1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
|
<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="generator" content="Docutils 0.17.1: http://docutils.sourceforge.net/" />
<title>ctags</title>
<style type="text/css">
/*
:Author: David Goodger (goodger@python.org)
:Id: $Id: html4css1.css 7952 2016-07-26 18:15:59Z milde $
:Copyright: This stylesheet has been placed in the public domain.
Default cascading style sheet for the HTML output of Docutils.
See http://docutils.sf.net/docs/howto/html-stylesheets.html for how to
customize this style sheet.
*/
/* used to remove borders from tables and images */
.borderless, table.borderless td, table.borderless th {
border: 0 }
table.borderless td, table.borderless th {
/* Override padding for "table.docutils td" with "! important".
The right padding separates the table cells. */
padding: 0 0.5em 0 0 ! important }
.first {
/* Override more specific margin styles with "! important". */
margin-top: 0 ! important }
.last, .with-subtitle {
margin-bottom: 0 ! important }
.hidden {
display: none }
.subscript {
vertical-align: sub;
font-size: smaller }
.superscript {
vertical-align: super;
font-size: smaller }
a.toc-backref {
text-decoration: none ;
color: black }
blockquote.epigraph {
margin: 2em 5em ; }
dl.docutils dd {
margin-bottom: 0.5em }
object[type="image/svg+xml"], object[type="application/x-shockwave-flash"] {
overflow: hidden;
}
/* Uncomment (and remove this text!) to get bold-faced definition list terms
dl.docutils dt {
font-weight: bold }
*/
div.abstract {
margin: 2em 5em }
div.abstract p.topic-title {
font-weight: bold ;
text-align: center }
div.admonition, div.attention, div.caution, div.danger, div.error,
div.hint, div.important, div.note, div.tip, div.warning {
margin: 2em ;
border: medium outset ;
padding: 1em }
div.admonition p.admonition-title, div.hint p.admonition-title,
div.important p.admonition-title, div.note p.admonition-title,
div.tip p.admonition-title {
font-weight: bold ;
font-family: sans-serif }
div.attention p.admonition-title, div.caution p.admonition-title,
div.danger p.admonition-title, div.error p.admonition-title,
div.warning p.admonition-title, .code .error {
color: red ;
font-weight: bold ;
font-family: sans-serif }
/* Uncomment (and remove this text!) to get reduced vertical space in
compound paragraphs.
div.compound .compound-first, div.compound .compound-middle {
margin-bottom: 0.5em }
div.compound .compound-last, div.compound .compound-middle {
margin-top: 0.5em }
*/
div.dedication {
margin: 2em 5em ;
text-align: center ;
font-style: italic }
div.dedication p.topic-title {
font-weight: bold ;
font-style: normal }
div.figure {
margin-left: 2em ;
margin-right: 2em }
div.footer, div.header {
clear: both;
font-size: smaller }
div.line-block {
display: block ;
margin-top: 1em ;
margin-bottom: 1em }
div.line-block div.line-block {
margin-top: 0 ;
margin-bottom: 0 ;
margin-left: 1.5em }
div.sidebar {
margin: 0 0 0.5em 1em ;
border: medium outset ;
padding: 1em ;
background-color: #ffffee ;
width: 40% ;
float: right ;
clear: right }
div.sidebar p.rubric {
font-family: sans-serif ;
font-size: medium }
div.system-messages {
margin: 5em }
div.system-messages h1 {
color: red }
div.system-message {
border: medium outset ;
padding: 1em }
div.system-message p.system-message-title {
color: red ;
font-weight: bold }
div.topic {
margin: 2em }
h1.section-subtitle, h2.section-subtitle, h3.section-subtitle,
h4.section-subtitle, h5.section-subtitle, h6.section-subtitle {
margin-top: 0.4em }
h1.title {
text-align: center }
h2.subtitle {
text-align: center }
hr.docutils {
width: 75% }
img.align-left, .figure.align-left, object.align-left, table.align-left {
clear: left ;
float: left ;
margin-right: 1em }
img.align-right, .figure.align-right, object.align-right, table.align-right {
clear: right ;
float: right ;
margin-left: 1em }
img.align-center, .figure.align-center, object.align-center {
display: block;
margin-left: auto;
margin-right: auto;
}
table.align-center {
margin-left: auto;
margin-right: auto;
}
.align-left {
text-align: left }
.align-center {
clear: both ;
text-align: center }
.align-right {
text-align: right }
/* reset inner alignment in figures */
div.align-right {
text-align: inherit }
/* div.align-center * { */
/* text-align: left } */
.align-top {
vertical-align: top }
.align-middle {
vertical-align: middle }
.align-bottom {
vertical-align: bottom }
ol.simple, ul.simple {
margin-bottom: 1em }
ol.arabic {
list-style: decimal }
ol.loweralpha {
list-style: lower-alpha }
ol.upperalpha {
list-style: upper-alpha }
ol.lowerroman {
list-style: lower-roman }
ol.upperroman {
list-style: upper-roman }
p.attribution {
text-align: right ;
margin-left: 50% }
p.caption {
font-style: italic }
p.credits {
font-style: italic ;
font-size: smaller }
p.label {
white-space: nowrap }
p.rubric {
font-weight: bold ;
font-size: larger ;
color: maroon ;
text-align: center }
p.sidebar-title {
font-family: sans-serif ;
font-weight: bold ;
font-size: larger }
p.sidebar-subtitle {
font-family: sans-serif ;
font-weight: bold }
p.topic-title {
font-weight: bold }
pre.address {
margin-bottom: 0 ;
margin-top: 0 ;
font: inherit }
pre.literal-block, pre.doctest-block, pre.math, pre.code {
margin-left: 2em ;
margin-right: 2em }
pre.code .ln { color: grey; } /* line numbers */
pre.code, code { background-color: #eeeeee }
pre.code .comment, code .comment { color: #5C6576 }
pre.code .keyword, code .keyword { color: #3B0D06; font-weight: bold }
pre.code .literal.string, code .literal.string { color: #0C5404 }
pre.code .name.builtin, code .name.builtin { color: #352B84 }
pre.code .deleted, code .deleted { background-color: #DEB0A1}
pre.code .inserted, code .inserted { background-color: #A3D289}
span.classifier {
font-family: sans-serif ;
font-style: oblique }
span.classifier-delimiter {
font-family: sans-serif ;
font-weight: bold }
span.interpreted {
font-family: sans-serif }
span.option {
white-space: nowrap }
span.pre {
white-space: pre }
span.problematic {
color: red }
span.section-subtitle {
/* font-size relative to parent (h1..h6 element) */
font-size: 80% }
table.citation {
border-left: solid 1px gray;
margin-left: 1px }
table.docinfo {
margin: 2em 4em }
table.docutils {
margin-top: 0.5em ;
margin-bottom: 0.5em }
table.footnote {
border-left: solid 1px black;
margin-left: 1px }
table.docutils td, table.docutils th,
table.docinfo td, table.docinfo th {
padding-left: 0.5em ;
padding-right: 0.5em ;
vertical-align: top }
table.docutils th.field-name, table.docinfo th.docinfo-name {
font-weight: bold ;
text-align: left ;
white-space: nowrap ;
padding-left: 0 }
/* "booktabs" style (no vertical lines) */
table.docutils.booktabs {
border: 0px;
border-top: 2px solid;
border-bottom: 2px solid;
border-collapse: collapse;
}
table.docutils.booktabs * {
border: 0px;
}
table.docutils.booktabs th {
border-bottom: thin solid;
text-align: left;
}
h1 tt.docutils, h2 tt.docutils, h3 tt.docutils,
h4 tt.docutils, h5 tt.docutils, h6 tt.docutils {
font-size: 100% }
ul.auto-toc {
list-style-type: none }
</style>
</head>
<body>
<div class="document" id="ctags">
<span id="ctags-1"></span>
<h1 class="title">ctags</h1>
<h2 class="subtitle" id="generate-tag-files-for-source-code">Generate tag files for source code</h2>
<table class="docinfo" frame="void" rules="none">
<col class="docinfo-name" />
<col class="docinfo-content" />
<tbody valign="top">
<tr><th class="docinfo-name">Version:</th>
<td>5.9.0</td></tr>
<tr class="manual-group field"><th class="docinfo-name">Manual group:</th><td class="field-body">Universal Ctags</td>
</tr>
<tr class="manual-section field"><th class="docinfo-name">Manual section:</th><td class="field-body">1</td>
</tr>
</tbody>
</table>
<div class="section" id="synopsis">
<h1>SYNOPSIS</h1>
<div class="line-block">
<div class="line"><strong>ctags</strong> [<options>] [<source_file(s)>]</div>
<div class="line"><strong>etags</strong> [<options>] [<source_file(s)>]</div>
</div>
</div>
<div class="section" id="description">
<h1>DESCRIPTION</h1>
<p>The <em>ctags</em> and <em>etags</em> (see <tt class="docutils literal"><span class="pre">-e</span></tt> option) programs
(hereinafter collectively referred to as ctags,
except where distinguished) generate an index (or "tag") file for a
variety of <em>language objects</em> found in <em>source file(s)</em>. This tag file allows
these items to be quickly and easily located by a text editor or other
utilities (<em>client tools</em>). A <em>tag</em> signifies a language object for which an index entry is
available (or, alternatively, the index entry created for that object).</p>
<p>Alternatively, ctags can generate a cross reference
file which lists, in human readable form, information about the various
language objects found in a set of source files.</p>
<p>Tag index files are supported by numerous editors, which allow the user to
locate the object associated with a name appearing in a source file and
jump to the file and line which defines the name. See the manual of your
favorite editor about utilizing ctags command and
the tag index files in the editor.</p>
<p>ctags is capable of generating different <em>kinds</em> of tags
for each of many different <em>languages</em>. For a complete list of supported
languages, the names by which they are recognized, and the kinds of tags
which are generated for each, see the <tt class="docutils literal"><span class="pre">--list-languages</span></tt> and <tt class="docutils literal"><span class="pre">--list-kinds-full</span></tt>
options.</p>
<p>This man page describes <em>Universal Ctags</em>, an implementation of ctags
derived from <em>Exuberant Ctags</em>. The major incompatible changes between
Universal Ctags and Exuberant Ctags are enumerated in
ctags-incompatibilities(7).</p>
<p>One of the advantages of Exuberant Ctags is that it allows a user to
define a new parser from the command line. Extending this capability is one
of the major features of Universal Ctags. ctags-optlib(7)
describes how the capability is extended.</p>
<p>Newly introduced experimental features are not explained here. If you
are interested in such features and ctags internals,
visit <a class="reference external" href="https://docs.ctags.io/">https://docs.ctags.io/</a>.</p>
</div>
<div class="section" id="command-line-interface">
<h1>COMMAND LINE INTERFACE</h1>
<p>Despite the wealth of available options, defaults are set so that
ctags is most commonly executed without any options (e.g.
"<tt class="docutils literal">ctags *</tt>", or "<tt class="docutils literal">ctags <span class="pre">-R</span></tt>"), which will
create a tag file in the current directory for all recognized source
files. The options described below are provided merely to allow custom
tailoring to meet special needs.</p>
<p>Note that spaces separating the single-letter options from their parameters
are optional.</p>
<p>Note also that the boolean parameters to the long form options (those
beginning with <tt class="docutils literal"><span class="pre">--</span></tt> and that take a <tt class="docutils literal"><span class="pre">[=(yes|no)]</span></tt> parameter) may be omitted,
in which case <tt class="docutils literal">=yes</tt> is implied. (e.g. <tt class="docutils literal"><span class="pre">--sort</span></tt> is equivalent to <tt class="docutils literal"><span class="pre">--sort=yes</span></tt>).
Note further that <tt class="docutils literal">=1</tt>, <tt class="docutils literal">=on</tt>, and <tt class="docutils literal">=true</tt> are considered synonyms for <tt class="docutils literal">=yes</tt>,
and that <tt class="docutils literal">=0</tt>, <tt class="docutils literal">=off</tt>, and <tt class="docutils literal">=false</tt> are considered synonyms for <tt class="docutils literal">=no</tt>.</p>
<p>Some options are either ignored or useful only when used while running in
etags mode (see <tt class="docutils literal"><span class="pre">-e</span></tt> option). Such options will be noted.</p>
<p><em><options></em> must precede the <em><source_file(s)></em> following the standard POSIX
convention.</p>
<p>Options taking language names will accept those names in either upper or
lower case. See the <tt class="docutils literal"><span class="pre">--list-languages</span></tt> option for a complete list of the
built-in language names.</p>
<div class="section" id="letters-and-names">
<h2>Letters and names</h2>
<p>Some options take one-letter flags as parameters (e.g. <tt class="docutils literal"><span class="pre">--kinds-<LANG></span></tt> option).
Specifying just letters help a user create a complicated command line
quickly. However, a command line including sequences of one-letter flags
becomes difficult to understand.</p>
<p>Universal Ctags accepts long-name flags in
addition to such one-letter flags. The long-name and one-letter flags can be mixed in an
option parameter by surrounding each long-name by braces. Thus, for an
example, the following three notations for <tt class="docutils literal"><span class="pre">--kinds-C</span></tt> option have
the same meaning:</p>
<pre class="literal-block">
--kinds-C=+pLl
--kinds-C=+{prototype}{label}{local}
--kinds-C=+{prototype}L{local}
</pre>
<p>Note that braces may be meta characters in your shell. Put
single quotes in such case.</p>
<p><tt class="docutils literal"><span class="pre">--list-...</span></tt> options shows one-letter flags and associated long-name flags.</p>
</div>
<div class="section" id="list-options">
<h2>List options</h2>
<p>Universal Ctags introduces many <tt class="docutils literal"><span class="pre">--list-...</span></tt> options that provide
the internal data of Universal Ctags (See "<a class="reference internal" href="#listing-options">Listing Options</a>"). Both users and client tools may
use the data. <tt class="docutils literal"><span class="pre">--with-list-header</span></tt> and <tt class="docutils literal"><span class="pre">--machinable</span></tt> options
adjust the output of the most of <tt class="docutils literal"><span class="pre">--list-...</span></tt> options.</p>
<p>The default setting (<tt class="docutils literal"><span class="pre">--with-list-header=yes</span></tt> and <tt class="docutils literal"><span class="pre">--machinable=no</span></tt>)
is for using interactively from a terminal. The header that explains
the meaning of columns is simply added to the output, and each column is
aligned in all lines. The header line starts with a hash ('<tt class="docutils literal">#</tt>') character.</p>
<p>For scripting in a client tool, <tt class="docutils literal"><span class="pre">--with-list-header=no</span></tt> and
<tt class="docutils literal"><span class="pre">--machinable=yes</span></tt> may be useful. The header is not added to the
output, and each column is separated by tab characters.</p>
<p>Note the order of columns will change in the future release.
However, labels in the header will not change. So by scanning
the header, a client tool can find the index for the target
column.</p>
<!-- options that should be explained and revised here
``- -list-features`` (done)
``- -machinable`` (done)
``- -with-list-header`` (done) -->
</div>
</div>
<div class="section" id="options">
<h1>OPTIONS</h1>
<p>ctags has more options than listed here.
Options starting with an underscore character, such as <tt class="docutils literal"><span class="pre">--_echo=<msg></span></tt>,
are not listed here. They are experimental or for debugging purpose.</p>
<p>Notation: <tt class="docutils literal"><foo></tt> is for a variable string <tt class="docutils literal">foo</tt>, <tt class="docutils literal">[ ... ]</tt> for optional,
<tt class="docutils literal">|</tt> for selection, and <tt class="docutils literal">( ... )</tt> for grouping. For example
<tt class="docutils literal"><span class="pre">--foo[=(yes|no)]''</span> means <span class="pre">``--foo</span></tt>, <tt class="docutils literal"><span class="pre">-foo=yes</span></tt>, or <tt class="docutils literal"><span class="pre">-foo=no</span></tt>.</p>
<div class="section" id="input-output-file-options">
<span id="option-input-output-file"></span><h2>Input/Output File Options</h2>
<dl class="docutils">
<dt><tt class="docutils literal"><span class="pre">--exclude=<pattern></span></tt></dt>
<dd><p class="first">Add <em><pattern></em> to a list of excluded files and directories. This option may
be specified as many times as desired. For each file name considered
by ctags, each pattern specified using this option
will be compared against both the complete path (e.g.
<tt class="docutils literal">some/path/base.ext</tt>) and the base name (e.g. <tt class="docutils literal">base.ext</tt>) of the file, thus
allowing patterns which match a given file name irrespective of its
path, or match only a specific path.</p>
<p>If appropriate support is available
from the runtime library of your C compiler, then pattern may
contain the usual shell wildcards (not regular expressions) common on
Unix (be sure to quote the option parameter to protect the wildcards from
being expanded by the shell before being passed to ctags;
also be aware that wildcards can match the slash character, '<tt class="docutils literal">/</tt>').
You can determine if shell wildcards are available on your platform by
examining the output of the <tt class="docutils literal"><span class="pre">--list-features</span></tt> option, which will include
<tt class="docutils literal">wildcards</tt> in the compiled feature list; otherwise, pattern is matched
against file names using a simple textual comparison.</p>
<p>If <em><pattern></em> begins with the character '<tt class="docutils literal">@</tt>', then the rest of the string
is interpreted as a file name from which to read exclusion patterns,
one per line. If pattern is empty, the list of excluded patterns is
cleared.</p>
<p>Note that at program startup, the default exclude list contains names of
common hidden and system files, patterns for binary files, and directories
for which it is generally not desirable to descend while processing the
<tt class="docutils literal"><span class="pre">--recurse</span></tt> option. To see the list of built-in exclude patterns, use
<tt class="docutils literal"><span class="pre">--list-excludes</span></tt>.</p>
<p class="last">See also the description for <tt class="docutils literal"><span class="pre">--exclude-exception=</span></tt> option.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--exclude-exception=<pattern></span></tt></dt>
<dd><p class="first">Add <em><pattern></em> to a list of included files and directories. The pattern
affects the files and directories that are excluded by the pattern
specified with <tt class="docutils literal"><span class="pre">--exclude=</span></tt> option.</p>
<p class="last">For an example, you want ctags to ignore all files
under <tt class="docutils literal">foo</tt> directory except <tt class="docutils literal">foo/main.c</tt>, use the following command
line: <tt class="docutils literal"><span class="pre">--exclude=foo/*</span> <span class="pre">--exclude-exception=foo/main.c</span></tt>.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--filter[=(yes|no)]</span></tt></dt>
<dd>Makes ctags behave as a filter, reading source
file names from standard input and printing their tags to standard
output on a file-by-file basis. If <tt class="docutils literal"><span class="pre">--sort</span></tt> is enabled, tags are sorted
only within the source file in which they are defined. File names are
read from standard input in line-oriented input mode (see note for <tt class="docutils literal"><span class="pre">-L</span></tt>
option) and only after file names listed on the command line or from
any file supplied using the <tt class="docutils literal"><span class="pre">-L</span></tt> option. When this option is enabled,
the options <tt class="docutils literal"><span class="pre">-f</span></tt>, <tt class="docutils literal"><span class="pre">-o</span></tt>, and <tt class="docutils literal"><span class="pre">--totals</span></tt> are ignored. This option is quite
esoteric and is disabled by default.</dd>
<dt><tt class="docutils literal"><span class="pre">--filter-terminator=<string></span></tt></dt>
<dd><p class="first">Specifies a <em><string></em> to print to standard output following the tags for
each file name parsed when the <tt class="docutils literal"><span class="pre">--filter</span></tt> option is enabled. This may
permit an application reading the output of ctags
to determine when the output for each file is finished.</p>
<p>Note that if the
file name read is a directory and <tt class="docutils literal"><span class="pre">--recurse</span></tt> is enabled, this string will
be printed only once at the end of all tags found for by descending
the directory. This string will always be separated from the last tag
line for the file by its terminating newline.</p>
<p class="last">This option is quite esoteric and is empty by default.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--links[=(yes|no)]</span></tt></dt>
<dd>Indicates whether symbolic links (if supported) should be followed.
When disabled, symbolic links are ignored. This option is on by default.</dd>
<dt><tt class="docutils literal"><span class="pre">--maxdepth=<N></span></tt></dt>
<dd>Limits the depth of directory recursion enabled with the <tt class="docutils literal"><span class="pre">--recurse</span></tt>
(<tt class="docutils literal"><span class="pre">-R</span></tt>) option.</dd>
<dt><tt class="docutils literal"><span class="pre">--recurse[=(yes|no)]</span></tt></dt>
<dd><p class="first">Recurse into directories encountered in the list of supplied files.</p>
<p>If the list of supplied files is empty and no file list is specified with
the <tt class="docutils literal"><span class="pre">-L</span></tt> option, then the current directory (i.e. '<tt class="docutils literal">.</tt>') is assumed.
Symbolic links are followed by default (See <tt class="docutils literal"><span class="pre">--links</span></tt> option). If you don't like these behaviors, either
explicitly specify the files or pipe the output of <tt class="docutils literal">find(1)</tt> into
"<tt class="docutils literal">ctags <span class="pre">-L</span> -</tt>" instead. See, also, the <tt class="docutils literal"><span class="pre">--exclude</span></tt> and
<tt class="docutils literal"><span class="pre">--maxdepth</span></tt> to limit recursion.</p>
<p class="last">Note: This option is not supported on
all platforms at present. It is available if the output of the <tt class="docutils literal"><span class="pre">--help</span></tt>
option includes this option.</p>
</dd>
</dl>
<!-- TODO(code): - -list-features option should support this. -->
<dl class="docutils">
<dt><tt class="docutils literal"><span class="pre">-R</span></tt></dt>
<dd>Equivalent to <tt class="docutils literal"><span class="pre">--recurse</span></tt>.</dd>
<dt><tt class="docutils literal"><span class="pre">-L</span> <file></tt></dt>
<dd><p class="first">Read from <em><file></em> a list of file names for which tags should be generated.</p>
<p>If file is specified as '<tt class="docutils literal">-</tt>', then file names are read from standard
input. File names read using this option are processed following file
names appearing on the command line. Options are also accepted in this
input. If this option is specified more than once, only the last will
apply.</p>
<p class="last">Note: file is read in line-oriented mode, where a new line is
the only delimiter and non-trailing white space is considered significant,
in order that file names containing spaces may be supplied
(however, trailing white space is stripped from lines); this can affect
how options are parsed if included in the input.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--append[=(yes|no)]</span></tt></dt>
<dd>Indicates whether tags generated from the specified files should be
appended to those already present in the tag file or should replace them.
This option is <tt class="docutils literal">no</tt> by default.</dd>
<dt><tt class="docutils literal"><span class="pre">-a</span></tt></dt>
<dd>Equivalent to <tt class="docutils literal"><span class="pre">--append</span></tt>.</dd>
<dt><tt class="docutils literal"><span class="pre">-f</span> <tagfile></tt></dt>
<dd><p class="first">Use the name specified by <em><tagfile></em> for the tag file (default is "<tt class="docutils literal">tags</tt>",
or "<tt class="docutils literal">TAGS</tt>" when running in etags mode). If <em><tagfile></em> is specified as '<tt class="docutils literal">-</tt>',
then the tags are written to standard output instead.</p>
<p>ctags
will stubbornly refuse to take orders if tagfile exists and
its first line contains something other than a valid tags line. This
will save your neck if you mistakenly type "<tt class="docutils literal">ctags <span class="pre">-f</span>
*.c</tt>", which would otherwise overwrite your first C file with the tags
generated by the rest! It will also refuse to accept a multi-character
file name which begins with a '<tt class="docutils literal">-</tt>' (dash) character, since this most
likely means that you left out the tag file name and this option tried to
grab the next option as the file name. If you really want to name your
output tag file <tt class="docutils literal"><span class="pre">-ugly</span></tt>, specify it as "<tt class="docutils literal"><span class="pre">-f</span> <span class="pre">./-ugly</span></tt>".</p>
<p class="last">This option must
appear before the first file name. If this option is specified more
than once, only the last will apply.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">-o</span> <tagfile></tt></dt>
<dd>Equivalent to "<tt class="docutils literal"><span class="pre">-f</span> tagfile</tt>".</dd>
</dl>
</div>
<div class="section" id="output-format-options">
<span id="option-output-format"></span><h2>Output Format Options</h2>
<dl class="docutils">
<dt><tt class="docutils literal"><span class="pre">--format=(1|2)</span></tt></dt>
<dd>Change the format of the output tag file. Currently the only valid
values for level are 1 or 2. Level 1 specifies the original tag file
format and level 2 specifies a new extended format containing extension
fields (but in a manner which retains backward-compatibility with
original <tt class="docutils literal">vi(1)</tt> implementations). The default level is 2.
[Ignored in etags mode]</dd>
<dt><tt class="docutils literal"><span class="pre">--output-format=(u-ctags|e-ctags|etags|xref|json)</span></tt></dt>
<dd>Specify the output format. The default is <tt class="docutils literal"><span class="pre">u-ctags</span></tt>.
See tags(5) for <tt class="docutils literal"><span class="pre">u-ctags</span></tt> and <tt class="docutils literal"><span class="pre">e-ctags</span></tt>.
See <tt class="docutils literal"><span class="pre">-e</span></tt> for <tt class="docutils literal">etags</tt>, and <tt class="docutils literal"><span class="pre">-x</span></tt> for <tt class="docutils literal">xref</tt>.
<tt class="docutils literal">json</tt> format is available only if
the ctags executable is built with <tt class="docutils literal">libjansson</tt>.
See ctags-client-tools(7) for more about <tt class="docutils literal">json</tt> format.</dd>
<dt><tt class="docutils literal"><span class="pre">-e</span></tt></dt>
<dd>Same as <tt class="docutils literal"><span class="pre">--output-format=etags</span></tt>.
Enable etags mode, which will create a tag file for use with the Emacs
editor. Alternatively, if ctags is invoked by a
name containing the string "etags" (either by renaming,
or creating a link to, the executable), etags mode will be enabled.</dd>
<dt><tt class="docutils literal"><span class="pre">-x</span></tt></dt>
<dd><p class="first">Same as <tt class="docutils literal"><span class="pre">--output-format=xref</span></tt>.
Print a tabular, human-readable cross reference (xref) file to standard
output instead of generating a tag file. The information contained in
the output includes: the tag name; the kind of tag; the line number,
file name, and source line (with extra white space condensed) of the
file which defines the tag. No tag file is written and all options
affecting tag file output will be ignored.</p>
<p class="last">Example applications for this
feature are generating a listing of all functions located in a source
file (e.g. "<tt class="docutils literal">ctags <span class="pre">-x</span> <span class="pre">--kinds-c=f</span> file</tt>"), or generating
a list of all externally visible global variables located in a source
file (e.g. "<tt class="docutils literal">ctags <span class="pre">-x</span> <span class="pre">--kinds-c=v</span> <span class="pre">--extras=-F</span> file</tt>").</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--sort=(yes|no|foldcase)</span></tt></dt>
<dd>Indicates whether the tag file should be sorted on the tag name
(default is <tt class="docutils literal">yes</tt>). Note that the original <tt class="docutils literal">vi(1)</tt> required sorted tags.
The <tt class="docutils literal">foldcase</tt> value specifies case insensitive (or case-folded) sorting.
Fast binary searches of tag files sorted with case-folding will require
special support from tools using tag files, such as that found in the
ctags readtags library, or Vim version 6.2 or higher
(using "<tt class="docutils literal">set ignorecase</tt>").
[Ignored in etags mode]</dd>
<dt><tt class="docutils literal"><span class="pre">-u</span></tt></dt>
<dd>Equivalent to <tt class="docutils literal"><span class="pre">--sort=no</span></tt> (i.e. "unsorted").</dd>
<dt><tt class="docutils literal"><span class="pre">--etags-include=<file></span></tt></dt>
<dd>Include a reference to <em><file></em> in the tag file. This option may be specified
as many times as desired. This supports Emacs' capability to use a
tag file which <em>includes</em> other tag files. [Available only in etags mode]</dd>
<dt><tt class="docutils literal"><span class="pre">--input-encoding=<encoding></span></tt></dt>
<dd>Specifies the <em><encoding></em> of the input files.
If this option is specified, Universal Ctags converts the input from this
encoding to the encoding specified by <tt class="docutils literal"><span class="pre">--output-encoding=encoding</span></tt>.</dd>
<dt><tt class="docutils literal"><span class="pre">--input-encoding-<LANG>=<encoding></span></tt></dt>
<dd>Specifies a specific input <em><encoding></em> for <em><LANG></em>. It overrides the global
default value given with <tt class="docutils literal"><span class="pre">--input-encoding</span></tt>.</dd>
<dt><tt class="docutils literal"><span class="pre">--output-encoding=<encoding></span></tt></dt>
<dd><p class="first">Specifies the <em><encoding></em> of the tags file.
Universal Ctags converts the encoding of input files from the encoding
specified by <tt class="docutils literal"><span class="pre">--input-encoding=<encoding></span></tt> to this encoding.</p>
<p class="last">In addition <em><encoding></em> is specified at the top the tags file as the
value for the <tt class="docutils literal">TAG_FILE_ENCODING</tt> pseudo-tag. The default value of
<em><encoding></em> is <tt class="docutils literal"><span class="pre">UTF-8</span></tt>.</p>
</dd>
</dl>
</div>
<div class="section" id="language-selection-and-mapping-options">
<span id="option-lang-mapping"></span><h2>Language Selection and Mapping Options</h2>
<dl class="docutils">
<dt><tt class="docutils literal"><span class="pre">--language-force=(<language>|auto)</span></tt></dt>
<dd><p class="first">By default, ctags automatically selects the language
of a source file, ignoring those files whose language cannot be
determined (see "<a class="reference internal" href="#determining-file-language">Determining file language</a>"). This option forces the specified
<em>language</em> (case-insensitive; either built-in or user-defined) to be used
for every supplied file instead of automatically selecting the language
based upon its extension.</p>
<p class="last">In addition, the special value <tt class="docutils literal">auto</tt> indicates
that the language should be automatically selected (which effectively
disables this option).</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--languages=[+|-](<list>|all)</span></tt></dt>
<dd><p class="first">Specifies the languages for which tag generation is enabled, with <em><list></em>
containing a comma-separated list of language names (case-insensitive;
either built-in or user-defined).</p>
<p>If the first language of <em><list></em> is not
preceded by either a '<tt class="docutils literal">+</tt>' or '<tt class="docutils literal">-</tt>', the current list (the current settings
of enabled/disabled languages managed in ctags internally)
will be cleared before adding or removing the languages in <em><list></em>. Until a '<tt class="docutils literal">-</tt>' is
encountered, each language in the <em><list></em> will be added to the current list.</p>
<p>As either the '<tt class="docutils literal">+</tt>' or '<tt class="docutils literal">-</tt>' is encountered in the <em><list></em>, the languages
following it are added or removed from the current list, respectively.
Thus, it becomes simple to replace the current list with a new one, or
to add or remove languages from the current list.</p>
<p>The actual list of
files for which tags will be generated depends upon the language
extension mapping in effect (see the <tt class="docutils literal"><span class="pre">--langmap</span></tt> option). Note that the most of
languages, including user-defined languages, are enabled unless explicitly
disabled using this option. Language names included in list may be any
built-in language or one previously defined with <tt class="docutils literal"><span class="pre">--langdef</span></tt>.</p>
<p>The default
is <tt class="docutils literal">all</tt>, which is also accepted as a valid argument. See the
<tt class="docutils literal"><span class="pre">--list-languages</span></tt> option for a list of the all (built-in and user-defined)
language names.</p>
<p class="last">Note <tt class="docutils literal"><span class="pre">--languages=</span></tt> option works cumulative way; the option can be
specified with different arguments multiple times in a command line.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--alias-<LANG>=[+|-](<pattern>|default)</span></tt></dt>
<dd><p class="first">Adds ('<tt class="docutils literal">+</tt>') or removes ('<tt class="docutils literal">-</tt>') an alias <em><pattern></em> to a language specified
with <em><LANG></em>. ctags refers to the alias pattern in
"<a class="reference internal" href="#determining-file-language">Determining file language</a>" stage.</p>
<p>The parameter <em><pattern></em> is not a list. Use this option multiple
times in a command line to add or remove multiple alias
patterns.</p>
<p>To restore the default language aliases, specify <tt class="docutils literal">default</tt>.</p>
<p>Using <tt class="docutils literal">all</tt> for <em><LANG></em> has meaning in following two cases:</p>
<dl class="last docutils">
<dt><tt class="docutils literal"><span class="pre">--alias-all=</span></tt></dt>
<dd>This clears aliases setting of all languages.</dd>
<dt><tt class="docutils literal"><span class="pre">--alias-all=default</span></tt></dt>
<dd>This restores the default languages aliases for all languages.</dd>
</dl>
</dd>
<dt><tt class="docutils literal"><span class="pre">--guess-language-eagerly</span></tt></dt>
<dd>Looks into the file contents for heuristically guessing the proper language parser.
See "<a class="reference internal" href="#determining-file-language">Determining file language</a>".</dd>
<dt><tt class="docutils literal"><span class="pre">-G</span></tt></dt>
<dd>Equivalent to <tt class="docutils literal"><span class="pre">--guess-language-eagerly</span></tt>.</dd>
<dt><tt class="docutils literal"><span class="pre">--langmap=<map>[,<map>[...]]</span></tt></dt>
<dd><p class="first">Controls how file names are mapped to languages (see the <tt class="docutils literal"><span class="pre">--list-maps</span></tt>
option). Each comma-separated <em><map></em> consists of the language name (either
a built-in or user-defined language), a colon, and a list of <em>file
extensions</em> and/or <em>file name patterns</em>. A file extension is specified by
preceding the extension with a period (e.g. <tt class="docutils literal">.c</tt>). A file name pattern
is specified by enclosing the pattern in parentheses (e.g.
<tt class="docutils literal">([Mm]akefile)</tt>).</p>
<p>If appropriate support is available from the runtime
library of your C compiler, then the file name pattern may contain the usual
shell wildcards common on Unix (be sure to quote the option parameter to
protect the wildcards from being expanded by the shell before being
passed to ctags). You can determine if shell wildcards
are available on your platform by examining the output of the
<tt class="docutils literal"><span class="pre">--list-features</span></tt> option, which will include <tt class="docutils literal">wildcards</tt> in the compiled
feature list; otherwise, the file name patterns are matched against
file names using a simple textual comparison.</p>
<p>When mapping a file extension with <tt class="docutils literal"><span class="pre">--langmap</span></tt> option,
it will first be unmapped from any other languages. (<tt class="docutils literal"><span class="pre">--map-<LANG></span></tt>
option provides more fine-grained control.)</p>
<p>If the first character in a <em><map></em> is a plus sign ('<tt class="docutils literal">+</tt>'), then the extensions and
file name patterns in that map will be appended to the current map
for that language; otherwise, the map will replace the current map.
For example, to specify that only files with extensions of <tt class="docutils literal">.c</tt> and <tt class="docutils literal">.x</tt> are
to be treated as C language files, use <tt class="docutils literal"><span class="pre">--langmap=c:.c.x</span></tt>; to also add
files with extensions of <tt class="docutils literal">.j</tt> as Java language files, specify
<tt class="docutils literal"><span class="pre">--langmap=c:.c.x,java:+.j</span></tt>. To map makefiles (e.g. files named either
<tt class="docutils literal">Makefile</tt>, <tt class="docutils literal">makefile</tt>, or having the extension <tt class="docutils literal">.mak</tt>) to a language
called <tt class="docutils literal">make</tt>, specify <tt class="docutils literal"><span class="pre">--langmap=make:([Mm]akefile).mak</span></tt>. To map files
having no extension, specify a period not followed by a non-period
character (e.g. '<tt class="docutils literal">.</tt>', <tt class="docutils literal">..x</tt>, <tt class="docutils literal">.x.</tt>).</p>
<p>To clear the mapping for a
particular language (thus inhibiting automatic generation of tags for
that language), specify an empty extension list (e.g. <tt class="docutils literal"><span class="pre">--langmap=fortran:</span></tt>).
To restore the default language mappings for a particular language,
supply the keyword <tt class="docutils literal">default</tt> for the mapping. To specify restore the
default language mappings for all languages, specify <tt class="docutils literal"><span class="pre">--langmap=default</span></tt>.</p>
<p class="last">Note that file name patterns are tested before file extensions when inferring
the language of a file. This order of Universal Ctags is different from
Exuberant Ctags. See ctags-incompatibilities(7) for the background of
this incompatible change.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--map-<LANG>=[+|-]<extension>|<pattern></span></tt></dt>
<dd><p class="first">This option provides the way to control mapping(s) of file names to
languages in a more fine-grained way than <tt class="docutils literal"><span class="pre">--langmap</span></tt> option.</p>
<p>In ctags, more than one language can map to a
file name <em><pattern></em> or file <em><extension></em> (<em>N:1 map</em>). Alternatively,
<tt class="docutils literal"><span class="pre">--langmap</span></tt> option handle only <em>1:1 map</em>, only one language
mapping to one file name <em><pattern></em> or file <em><extension></em>. A typical N:1
map is seen in C++ and ObjectiveC language; both languages have
a map to <tt class="docutils literal">.h</tt> as a file extension.</p>
<p>A file extension is specified by preceding the extension with a period (e.g. <tt class="docutils literal">.c</tt>).
A file name pattern is specified by enclosing the pattern in parentheses (e.g.
<tt class="docutils literal">([Mm]akefile)</tt>). A prefixed plus ('<tt class="docutils literal">+</tt>') sign is for adding, and
minus ('<tt class="docutils literal">-</tt>') is for removing. No prefix means replacing the map of <em><LANG></em>.</p>
<p class="last">Unlike <tt class="docutils literal"><span class="pre">--langmap</span></tt>, <em><extension></em> (or <em><pattern></em>) is not a list.
<tt class="docutils literal"><span class="pre">--map-<LANG></span></tt> takes one extension (or pattern). However,
the option can be specified with different arguments multiple times
in a command line.</p>
</dd>
</dl>
</div>
<div class="section" id="tags-file-contents-options">
<span id="option-tags-file-contents"></span><h2>Tags File Contents Options</h2>
<p>See "<a class="reference internal" href="#id1">TAG ENTRIES</a>" about fields, kinds, roles, and extras.</p>
<dl class="docutils">
<dt><tt class="docutils literal"><span class="pre">--excmd=(number|pattern|mix|combine)</span></tt></dt>
<dd><p class="first">Determines the type of <tt class="docutils literal">EX</tt> command used to locate tags in the source
file. [Ignored in etags mode]</p>
<p>The valid values for type (either the entire word or the first letter
is accepted) are:</p>
<dl class="last docutils">
<dt><tt class="docutils literal">number</tt></dt>
<dd><p class="first">Use only line numbers in the tag file for locating tags. This has
four advantages:</p>
<ol class="arabic simple">
<li>Significantly reduces the size of the resulting tag file.</li>
<li>Eliminates failures to find tags because the line defining the
tag has changed, causing the pattern match to fail (note that
some editors, such as <tt class="docutils literal">vim</tt>, are able to recover in many such
instances).</li>
<li>Eliminates finding identical matching, but incorrect, source
lines (see "<a class="reference internal" href="#bugs">BUGS</a>").</li>
<li>Retains separate entries in the tag file for lines which are
identical in content. In pattern mode, duplicate entries are
dropped because the search patterns they generate are identical,
making the duplicate entries useless.</li>
</ol>
<p>However, this option has one significant drawback: changes to the
source files can cause the line numbers recorded in the tag file
to no longer correspond to the lines in the source file, causing
jumps to some tags to miss the target definition by one or more
lines. Basically, this option is best used when the source code
to which it is applied is not subject to change. Selecting this
option type causes the following options to be ignored: <tt class="docutils literal"><span class="pre">-B</span></tt>, <tt class="docutils literal"><span class="pre">-F</span></tt>.</p>
<p class="last"><tt class="docutils literal">number</tt> type is ignored in Xref and JSON output formats. Use
<tt class="docutils literal"><span class="pre">--_xformat="...%n"</span></tt> for Xref output format, or <tt class="docutils literal"><span class="pre">--fields=+n-P</span></tt> for
JSON output format.</p>
<!-- NOTE: #2792 -->
</dd>
<dt><tt class="docutils literal">pattern</tt></dt>
<dd>Use only search patterns for all tags, rather than the line numbers
usually used for macro definitions. This has the advantage of
not referencing obsolete line numbers when lines have been added or
removed since the tag file was generated.</dd>
<dt><tt class="docutils literal">mixed</tt></dt>
<dd><p class="first">In this mode, patterns are generally used with a few exceptions.
For C, line numbers are used for macro definition tags. For Fortran, line numbers
are used for common blocks because their corresponding source lines
are generally identical, making pattern searches useless
for finding all matches.</p>
<p class="last">This was the default format generated by the original ctags and is,
therefore, retained as the default for this option.</p>
</dd>
<dt><tt class="docutils literal">combine</tt></dt>
<dd>Concatenate the line number and pattern with a semicolon in between.</dd>
</dl>
</dd>
<dt><tt class="docutils literal"><span class="pre">-n</span></tt></dt>
<dd>Equivalent to <tt class="docutils literal"><span class="pre">--excmd=number</span></tt>.</dd>
<dt><tt class="docutils literal"><span class="pre">-N</span></tt></dt>
<dd>Equivalent to <tt class="docutils literal"><span class="pre">--excmd=pattern</span></tt>.</dd>
<dt><tt class="docutils literal"><span class="pre">--extras=[+|-][<flags>|*]</span></tt></dt>
<dd><p class="first">Specifies whether to include extra tag entries for certain kinds of
information. See also "<a class="reference internal" href="#extras">Extras</a>" subsection to know what are extras.</p>
<p>The parameter <em><flags></em> is a set of one-letter flags (and/or long-name flags), each
representing one kind of extra tag entry to include in the tag file.
If flags is preceded by either the '<tt class="docutils literal">+</tt>' or '<tt class="docutils literal">-</tt>' character, the effect of
each flag is added to, or removed from, those currently enabled;
otherwise the flags replace any current settings. All entries are
included if '<tt class="docutils literal">*</tt>' is given.</p>
<p class="last">This <tt class="docutils literal"><span class="pre">--extras=</span></tt> option is for controlling extras common in all
languages (or language-independent extras). Universal Ctags also
supports language-specific extras. (See "<a class="reference internal" href="#language-specific-fields-and-extras">Language-specific fields and
extras</a>" about the concept). Use <tt class="docutils literal"><span class="pre">--extras-<LANG>=</span></tt> option for
controlling them.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--extras-(<LANG>|all)=[+|-][<flags>|*]</span></tt></dt>
<dd><p class="first">Specifies whether to include extra tag entries for certain kinds of
information for language <em><LANG></em>. Universal Ctags
introduces language-specific extras. See "<a class="reference internal" href="#language-specific-fields-and-extras">Language-specific fields and
extras</a>" about the concept. This option is for controlling them.</p>
<p>Specifies <tt class="docutils literal">all</tt> as <em><LANG></em> to apply the parameter <em><flags></em> to all
languages; all extras are enabled with specifying '<tt class="docutils literal">*</tt>' as the
parameter flags. If specifying nothing as the parameter flags
(<tt class="docutils literal"><span class="pre">--extras-all=</span></tt>), all extras are disabled. These two combinations
are useful for testing.</p>
<p class="last">Check the output of the <tt class="docutils literal"><span class="pre">--list-extras=<LANG></span></tt> option for the
extras of specific language <em><LANG></em>.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--fields=[+|-][<flags>|*]</span></tt></dt>
<dd><p class="first">Specifies which language-independent fields are to be included in the tag
entries. Language-independent fields are extension fields which are common
in all languages. See "<a class="reference internal" href="#tag-file-format">TAG FILE FORMAT</a>" section, and "<a class="reference internal" href="#extension-fields">Extension fields</a>"
subsection, for details of extension fields.</p>
<p>The parameter <em><flags></em> is a set of one-letter or long-name flags,
each representing one type of extension field to include.
Each flag or group of flags may be preceded by either '<tt class="docutils literal">+</tt>' to add it
to the default set, or '<tt class="docutils literal">-</tt>' to exclude it. In the absence of any
preceding '<tt class="docutils literal">+</tt>' or '<tt class="docutils literal">-</tt>' sign, only those fields explicitly listed in flags
will be included in the output (i.e. overriding the default set). All
fields are included if '<tt class="docutils literal">*</tt>' is given.</p>
<p>This option is ignored if the
option <tt class="docutils literal"><span class="pre">--format=1</span></tt> (legacy tag file format) has been specified.</p>
<p class="last">Use <tt class="docutils literal"><span class="pre">--fields-<LANG>=</span></tt> option for controlling language-specific fields.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--fields-(<LANG>|all)=[+|-][<flags>|*]</span></tt></dt>
<dd><p class="first">Specifies which language-specific fields are to be included in
the tag entries. Universal Ctags
supports language-specific fields. (See "<a class="reference internal" href="#language-specific-fields-and-extras">Language-specific fields and
extras</a>" about the concept).</p>
<p>Specify <tt class="docutils literal">all</tt> as <em><LANG></em> to apply the parameter <em><flags></em> to all
languages; all fields are enabled with specifying '<tt class="docutils literal">*</tt>' as the
parameter flags. If specifying nothing as the parameter <em><flags></em>
(i.e. <tt class="docutils literal"><span class="pre">--fields-all=</span></tt>), all fields are disabled. These two combinations
are useful for testing.</p>
<p>See the description of <tt class="docutils literal"><span class="pre">--fields=[+|-][<flags>|*]</span></tt> about <em><flags></em>.</p>
<p class="last">Use <tt class="docutils literal"><span class="pre">--fields=</span></tt> option for controlling language-independent fields.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--kinds-(<LANG>|all)=[+|-](<kinds>|*)</span></tt></dt>
<dd><p class="first">Specifies a list of language-specific <em><kinds></em> of tags (or kinds) to
include in the output file for a particular language, where <em><LANG></em> is
case-insensitive and is one of the built-in language names (see the
<tt class="docutils literal"><span class="pre">--list-languages</span></tt> option for a complete list).</p>
<p>The parameter <em><kinds></em> is a group
of one-letter or long-name flags designating kinds of tags (particular to the language)
to either include or exclude from the output. The specific sets of
flags recognized for each language, their meanings and defaults may be
list using the <tt class="docutils literal"><span class="pre">--list-kinds-full</span></tt> option.</p>
<p>Each letter or group of letters
may be preceded by either '<tt class="docutils literal">+</tt>' to add it to, or '<tt class="docutils literal">-</tt>' to remove it from,
the default set. In the absence of any preceding '<tt class="docutils literal">+</tt>' or '<tt class="docutils literal">-</tt>' sign, only
those kinds explicitly listed in kinds will be included in the output
(i.e. overriding the default for the specified language).</p>
<p>Specify '<tt class="docutils literal">*</tt>' as the parameter to include all kinds implemented
in <em><LANG></em> in the output. Furthermore if <tt class="docutils literal">all</tt> is given as <em><LANG></em>,
specification of the parameter <tt class="docutils literal">kinds</tt> affects all languages defined
in ctags. Giving <tt class="docutils literal">all</tt> makes sense only when '<tt class="docutils literal">*</tt>' or
'<tt class="docutils literal">F</tt>' is given as the parameter <tt class="docutils literal">kinds</tt>.</p>
<p>As an example for the C language, in order to add prototypes and
external variable declarations to the default set of tag kinds,
but exclude macros, use <tt class="docutils literal"><span class="pre">--kinds-c=+px-d</span></tt>; to include only tags for
functions, use <tt class="docutils literal"><span class="pre">--kinds-c=f</span></tt>.</p>
<p class="last">Some kinds of C and C++ languages are synchronized; enabling
(or disabling) a kind in one language enables the kind having
the same one-letter and long-name in the other language. See also the
description of <tt class="docutils literal">MASTER</tt> column of <tt class="docutils literal"><span class="pre">--list-kinds-full</span></tt>.</p>
</dd>
</dl>
<!-- COMMENT:
``- -param-<LANG>:name=argument`` is moved to "Language Specific Options" -->
<dl class="docutils">
<dt><tt class="docutils literal"><span class="pre">--pattern-length-limit=<N></span></tt></dt>
<dd><p class="first">Truncate patterns of tag entries after <em><N></em> characters. Disable by setting to 0
(default is 96).</p>
<p>An input source file with long lines and multiple tag matches per
line can generate an excessively large tags file with an
unconstrained pattern length. For example, running ctags on a
minified JavaScript source file often exhibits this behavior.</p>
<p class="last">The truncation avoids cutting in the middle of a UTF-8 code point
spanning multiple bytes to prevent writing invalid byte sequences from
valid input files. This handling allows for an extra 3 bytes above the
configured limit in the worse case of a 4 byte code point starting
right before the limit. Please also note that this handling is fairly
naive and fast, and although it is resistant against any input, it
requires a valid input to work properly; it is not guaranteed to work
as the user expects when dealing with partially invalid UTF-8 input.
This also partially affect non-UTF-8 input, if the byte sequence at
the truncation length looks like a multibyte UTF-8 sequence. This
should however be rare, and in the worse case will lead to including
up to an extra 3 bytes above the limit.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--pseudo-tags=[+|-](<pseudo-tag>|*)</span></tt></dt>
<dd>Enable/disable emitting pseudo-tag named <em><pseudo-tag></em>.
If '<tt class="docutils literal">*</tt>' is given, enable/disable emitting all pseudo-tags.</dd>
<dt><tt class="docutils literal"><span class="pre">--put-field-prefix</span></tt></dt>
<dd><p class="first">Put <tt class="docutils literal">UCTAGS</tt> as prefix for the name of fields newly introduced in
Universal Ctags.</p>
<p>Some fields are newly introduced in Universal Ctags and more will
be introduced in the future. Other tags generators may also
introduce their specific fields.</p>
<p>In such a situation, there is a concern about conflicting field
names; mixing tags files generated by multiple tags generators
including Universal Ctags is difficult. This option provides a
workaround for such station.</p>
<pre class="code console literal-block">
<span class="generic prompt">$ </span>ctags --fields<span class="operator">=</span><span class="literal string single">'{line}{end}'</span> -o - hello.c
<span class="generic output">main hello.c /^main(int argc, char **argv)$/;" f line:3 end:6
</span><span class="generic prompt">$ </span>ctags --put-field-prefix --fields<span class="operator">=</span><span class="literal string single">'{line}{end}'</span> -o - hello.c
<span class="generic output">main hello.c /^main(int argc, char **argv)$/;" f line:3 UCTAGSend:6</span>
</pre>
<p class="last">In the above example, the prefix is put to <tt class="docutils literal">end</tt> field which is
newly introduced in Universal Ctags.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--roles-(<LANG>|all).(<kind>|all)=[+|-][<roles>|*]</span></tt></dt>
<dd><p class="first">Specifies a list of kind-specific roles of tags to include in the
output file for a particular language.
<em><kind></em> specifies the kind where the <em><roles></em> are defined.
<em><LANG></em> specifies the language where the kind is defined.
Each role in <em><roles></em> must be surrounded by braces (e.g. <tt class="docutils literal">{system}</tt>
for a role named "system").</p>
<p>Like <tt class="docutils literal"><span class="pre">--kinds-<LANG></span></tt> option, '<tt class="docutils literal">+</tt>' is for adding the role to the
list, and '<tt class="docutils literal">-</tt>' is for removing from the list. '<tt class="docutils literal">*</tt>' is for including
all roles of the kind to the list. The option with no argument
makes the list empty.</p>
<p>Both a one-letter flag or a long name flag surrounded by braces are
acceptable for specifying a kind (e.g. <tt class="docutils literal"><span class="pre">--roles-C.h=+{system}{local}</span></tt>
or <tt class="docutils literal"><span class="pre">--roles-C.{header}=+{system}{local}</span></tt>). '<tt class="docutils literal">*</tt>' can be used for <em><KIND></em>
only for adding/removing all roles of all kinds in a language to/from
the list (e.g. <tt class="docutils literal"><span class="pre">--roles-C.*=*</span></tt> or <tt class="docutils literal"><span class="pre">--roles-C.*=</span></tt>).</p>
<p class="last"><tt class="docutils literal">all</tt> can be used for <em><LANG></em> only for adding/removing all roles of
all kinds in all languages to/from the list
(e.g. <tt class="docutils literal"><span class="pre">--roles-all.*=*</span></tt> or <tt class="docutils literal"><span class="pre">--roles-all.*=</span></tt>).</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--tag-relative=(yes|no|always|never)</span></tt></dt>
<dd><p class="first">Specifies how the file paths recorded in the tag file.
The default is <tt class="docutils literal">yes</tt> when running in etags mode (see
the <tt class="docutils literal"><span class="pre">-e</span></tt> option), <tt class="docutils literal">no</tt> otherwise.</p>
<dl class="last docutils">
<dt><tt class="docutils literal">yes</tt></dt>
<dd>indicates that the file paths recorded in the tag file should be
<em>relative to the directory containing the tag file</em>
unless the files supplied on the command line
are specified with absolute paths.</dd>
<dt><tt class="docutils literal">no</tt></dt>
<dd>indicates that the file paths recorded in the tag file should be
<em>relative to the current directory</em>
unless the files supplied on the command line
are specified with absolute paths.</dd>
<dt><tt class="docutils literal">always</tt></dt>
<dd>indicates the recorded file paths should be relative
even if source file names are passed in with absolute paths.</dd>
<dt><tt class="docutils literal">never</tt></dt>
<dd>indicates the recorded file paths should be absolute
even if source file names are passed in with relative paths.</dd>
</dl>
</dd>
<dt><tt class="docutils literal"><span class="pre">--use-slash-as-filename-separator[=(yes|no)]</span></tt></dt>
<dd><p class="first">Uses slash ('<tt class="docutils literal">/</tt>') character as filename separators instead of backslash
('<tt class="docutils literal">\</tt>') character when printing <tt class="docutils literal">input:</tt> field.
The default is <tt class="docutils literal">yes</tt> for the default "u-ctags" output format, and
<tt class="docutils literal">no</tt> for the other formats.</p>
<p class="last">This option is available on MS Windows only.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">-B</span></tt></dt>
<dd>Use backward searching patterns (e.g. <tt class="docutils literal"><span class="pre">?pattern?</span></tt>). [Ignored in etags mode]</dd>
<dt><tt class="docutils literal"><span class="pre">-F</span></tt></dt>
<dd>Use forward searching patterns (e.g. <tt class="docutils literal">/pattern/</tt>) (default). [Ignored
in etags mode]</dd>
</dl>
</div>
<div class="section" id="option-file-options">
<h2>Option File Options</h2>
<!-- TODO: merge some of description in option-file.rst into FILE or a dedicated
section -->
<dl class="docutils">
<dt><tt class="docutils literal"><span class="pre">--options=<pathname></span></tt></dt>
<dd><p class="first">Read additional options from file or directory.</p>
<p>ctags searches <em><pathname></em> in the optlib path list
first. If ctags cannot find a file or directory
in the list, ctags reads a file or directory
at the specified <em><pathname></em>.</p>
<p>If a file is specified, it should contain one option per line. If
a directory is specified, files suffixed with <tt class="docutils literal">.ctags</tt> under it
are read in alphabetical order.</p>
<p class="last">As a special case, if <tt class="docutils literal"><span class="pre">--options=NONE</span></tt> is specified as the first
option on the command line, preloading is disabled; the option
will disable the automatic reading of any configuration options
from a file (see "<a class="reference internal" href="#files">FILES</a>").</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--options-maybe=<pathname></span></tt></dt>
<dd>Same as <tt class="docutils literal"><span class="pre">--options</span></tt> but doesn't cause an error if file
(or directory) specified with <em><pathname></em> doesn't exist.</dd>
<dt><tt class="docutils literal"><span class="pre">--optlib-dir=[+]<directory></span></tt></dt>
<dd>Add an optlib <em><directory></em> to or reset the optlib path list.
By default, the optlib path list is empty.</dd>
</dl>
</div>
<div class="section" id="optlib-options">
<h2>optlib Options</h2>
<p>See ctags-optlib(7) for details of each option.</p>
<dl class="docutils">
<dt><tt class="docutils literal"><span class="pre">--kinddef-<LANG>=<letter>,<name>,<description></span></tt></dt>
<dd>Define a kind for <em><LANG></em>.
Don't be confused this with <tt class="docutils literal"><span class="pre">--kinds-<LANG></span></tt>.</dd>
<dt><tt class="docutils literal"><span class="pre">--langdef=<name></span></tt></dt>
<dd>Defines a new user-defined language, <em><name></em>, to be parsed with regular
expressions.</dd>
<dt><tt class="docutils literal"><span class="pre">--mline-regex-<LANG>=/<line_pattern>/<name_pattern>/<kind-spec>/[<flags>]</span></tt></dt>
<dd>Define multi-line regular expression for locating tags in specific language.</dd>
<dt><tt class="docutils literal"><span class="pre">--regex-<LANG>=/<line_pattern>/<name_pattern>/<kind-spec>/[<flags>]</span></tt></dt>
<dd>Define single-line regular expression for locating tags in specific language.</dd>
</dl>
</div>
<div class="section" id="language-specific-options">
<span id="option-lang-specific"></span><h2>Language Specific Options</h2>
<dl class="docutils">
<dt><tt class="docutils literal"><span class="pre">--if0[=(yes|no)]</span></tt></dt>
<dd><p class="first">Indicates a preference as to whether code within an "<tt class="docutils literal">#if 0</tt>" branch of a
preprocessor conditional should be examined for non-macro tags (macro
tags are always included). Because the intent of this construct is to
disable code, the default value of this option is <tt class="docutils literal">no</tt> (disabled).</p>
<p class="last">Note that this
indicates a preference only and does not guarantee skipping code within
an "<tt class="docutils literal">#if 0</tt>" branch, since the fall-back algorithm used to generate
tags when preprocessor conditionals are too complex follows all branches
of a conditional.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--line-directives[=(yes|no)]</span></tt></dt>
<dd><p class="first">Specifies whether <tt class="docutils literal">#line</tt> directives should be recognized. These are
present in the output of a preprocessor and contain the line number, and
possibly the file name, of the original source file(s) from which the
preprocessor output file was generated. This option is off by default.</p>
<p>When enabled, this option will
cause ctags to generate tag entries marked with the
file names and line numbers of their locations original source file(s),
instead of their actual locations in the preprocessor output. The actual
file names placed into the tag file will have the same leading path
components as the preprocessor output file, since it is assumed that
the original source files are located relative to the preprocessor
output file (unless, of course, the <tt class="docutils literal">#line</tt> directive specifies an
absolute path).</p>
<p class="last">Note: This option is generally
only useful when used together with the <tt class="docutils literal"><span class="pre">--excmd=number</span></tt> (<tt class="docutils literal"><span class="pre">-n</span></tt>) option.
Also, you may have to use either the <tt class="docutils literal"><span class="pre">--langmap</span></tt> or <tt class="docutils literal"><span class="pre">--language-force</span></tt> option
if the extension of the preprocessor output file is not known to
ctags.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">-D</span> <span class="pre"><macro>=<definition></span></tt></dt>
<dd>Defines a C preprocessor <em><macro></em>. This emulates the behavior of the
corresponding gcc option. All types of macros are supported,
including the ones with parameters and variable arguments.
Stringification, token pasting and recursive macro expansion are also
supported.
This extends the function provided by <tt class="docutils literal"><span class="pre">-I</span></tt> option.</dd>
<dt><tt class="docutils literal"><span class="pre">-h</span> <span class="pre">(<list>|default)</span></tt></dt>
<dd><p class="first">Specifies a <em><list></em> of file extensions, separated by periods, which are
to be interpreted as include (or header) files. To indicate files having
no extension, use a period not followed by a non-period character
(e.g. '<tt class="docutils literal">.</tt>', <tt class="docutils literal">..x</tt>, <tt class="docutils literal">.x.</tt>).</p>
<p>This option only affects how the scoping of
particular kinds of tags are interpreted (i.e. whether or not they are
considered as globally visible or visible only within the file in which
they are defined); it does not map the extension to any particular
language. Any tag which is located in a non-include file and cannot be
seen (e.g. linked to) from another file is considered to have file-limited
(e.g. static) scope. No kind of tag appearing in an include file
will be considered to have file-limited scope.</p>
<p>If the first character in the list is '<tt class="docutils literal">+</tt>', then the extensions in the list will be
appended to the current list; otherwise, the list will replace the
current list. See, also, the <tt class="docutils literal">fileScope</tt>/<tt class="docutils literal">F</tt> flag of <tt class="docutils literal"><span class="pre">--extras</span></tt> option.</p>
<p>The default list is
<tt class="docutils literal"><span class="pre">.h.H.hh.hpp.hxx.h++.inc.def</span></tt>. To restore the default list, specify "<tt class="docutils literal"><span class="pre">-h</span>
default</tt>".</p>
<p class="last">Note that if an extension supplied to this option is not
already mapped to a particular language (see "<a class="reference internal" href="#determining-file-language">Determining file language</a>", above),
you will also need to use either the <tt class="docutils literal"><span class="pre">--map-<LANG></span></tt>, <tt class="docutils literal"><span class="pre">--langmap</span></tt> or
<tt class="docutils literal"><span class="pre">--language-force</span></tt> option.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">-I</span> <span class="pre"><identifier-list></span></tt></dt>
<dd><p class="first">Specifies a <em><identifier-list></em> of identifiers which are to be specially handled while
parsing C and C++ source files. This option is specifically provided
to handle special cases arising through the use of preprocessor macros.
When the identifiers listed are simple identifiers, these identifiers
will be ignored during parsing of the source files.</p>
<p>If an identifier is
suffixed with a '<tt class="docutils literal">+</tt>' character (i.e. "<tt class="docutils literal"><span class="pre">-I</span> FOO+</tt>"), ctags will also
ignore any parenthesis-enclosed argument list which may immediately
follow the identifier in the source files. See the example of "<tt class="docutils literal"><span class="pre">-I</span>
MODULE_VERSION+</tt>" below.</p>
<p>If two identifiers are
separated with the '<tt class="docutils literal">=</tt>' character (i.e. <tt class="docutils literal"><span class="pre">-I</span> FOO=BAR</tt>), the first identifiers is replaced by
the second identifiers for parsing purposes. The list of identifiers may
be supplied directly on the command line or read in from a separate file.
See the example of "<tt class="docutils literal"><span class="pre">-I</span> CLASS=class</tt>" below.</p>
<p>If the first character of <em><identifier-list></em> is '<tt class="docutils literal">@</tt>', '<tt class="docutils literal">.</tt>' or a pathname
separator ('<tt class="docutils literal">/</tt>' or '<tt class="docutils literal">\</tt>'), or the first two characters specify a drive
letter (e.g. <tt class="docutils literal">C:</tt>), the parameter <em><identifier-list></em> will be interpreted as
a filename from which to read a list of identifiers, one per input line.</p>
<p>Otherwise, <em><identifier-list></em> is a list of identifiers (or identifier
pairs) to be specially handled, each delimited by either a comma or
by white space (in which case the list should be quoted to keep the
entire list as one command line argument).</p>
<p>Multiple <tt class="docutils literal"><span class="pre">-I</span></tt> options may be
supplied. To clear the list of ignore identifiers, supply a single
dash ('<tt class="docutils literal">-</tt>') for <em><identifier-list></em>.</p>
<p>This feature is useful when preprocessor macros are used in such a way
that they cause syntactic confusion due to their presence. Indeed,
this is the best way of working around a number of problems caused by
the presence of syntax-busting macros in source files (see "<a class="reference internal" href="#caveats">CAVEATS</a>").
Some examples will illustrate this point.</p>
<pre class="code C literal-block">
<span class="keyword type">int</span> <span class="name">foo</span> <span class="name">ARGDECL4</span><span class="punctuation">(</span><span class="keyword type">void</span> <span class="operator">*</span><span class="punctuation">,</span> <span class="name">ptr</span><span class="punctuation">,</span> <span class="keyword type">long</span> <span class="keyword type">int</span><span class="punctuation">,</span> <span class="name">nbytes</span><span class="punctuation">)</span>
</pre>
<p>In the above example, the macro <tt class="docutils literal">ARGDECL4</tt> would be mistakenly
interpreted to be the name of the function instead of the correct name
of <tt class="docutils literal">foo</tt>. Specifying "<tt class="docutils literal"><span class="pre">-I</span> ARGDECL4</tt>" results in the correct behavior.</p>
<pre class="code C literal-block">
<span class="comment multiline">/* creates an RCS version string in module */</span>
<span class="name">MODULE_VERSION</span><span class="punctuation">(</span><span class="literal string">"$Revision$"</span><span class="punctuation">)</span>
</pre>
<p>In the above example the macro invocation looks too much like a function
definition because it is not followed by a semicolon (indeed, it
could even be followed by a global variable definition that would look
much like a K&R style function parameter declaration). In fact, this
seeming function definition could possibly even cause the rest of the
file to be skipped over while trying to complete the definition.
Specifying "<tt class="docutils literal"><span class="pre">-I</span> MODULE_VERSION+</tt>" would avoid such a problem.</p>
<pre class="code C literal-block">
<span class="name">CLASS</span> <span class="name">Example</span> <span class="punctuation">{</span>
<span class="comment single">// your content here
</span><span class="punctuation">};</span>
</pre>
<p class="last">The example above uses <tt class="docutils literal">CLASS</tt> as a preprocessor macro which expands to
something different for each platform. For instance <tt class="docutils literal">CLASS</tt> may be
defined as <tt class="docutils literal">class __declspec(dllexport)</tt> on Win32 platforms and simply
<tt class="docutils literal">class</tt> on UNIX. Normally, the absence of the C++ keyword <tt class="docutils literal">class</tt>
would cause the source file to be incorrectly parsed. Correct behavior
can be restored by specifying "<tt class="docutils literal"><span class="pre">-I</span> CLASS=class</tt>".</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--param-<LANG>:<name>=<argument></span></tt></dt>
<dd><p class="first">Set a <em><LANG></em> specific parameter, a parameter specific to the <em><LANG></em>.</p>
<p class="last">Available parameters can be listed with <tt class="docutils literal"><span class="pre">--list-params</span></tt>.</p>
</dd>
</dl>
</div>
<div class="section" id="listing-options">
<span id="option-listing"></span><h2>Listing Options</h2>
<dl class="docutils">
<dt><tt class="docutils literal"><span class="pre">--list-aliases[=(<language>|all)]</span></tt></dt>
<dd>Lists the aliases for either the specified <em><language></em> or <tt class="docutils literal">all</tt>
languages, and then exits.
<tt class="docutils literal">all</tt> is used as default value if the option argument is omitted.
The aliases are used when heuristically testing a language parser for a
source file.</dd>
<dt><tt class="docutils literal"><span class="pre">--list-excludes</span></tt></dt>
<dd>Lists the current exclusion patterns used to exclude files.</dd>
<dt><tt class="docutils literal"><span class="pre">--list-extras[=(<language>|all)]</span></tt></dt>
<dd><p class="first">Lists the extras recognized for either the specified <em><language></em> or
<tt class="docutils literal">all</tt> languages. See "<a class="reference internal" href="#extras">Extras</a>" subsection to know what are extras.
<tt class="docutils literal">all</tt> is used as default value if the option argument is omitted.</p>
<p>An extra can be enabled or disabled with <tt class="docutils literal"><span class="pre">--extras=</span></tt> for common
extras in all languages, or <tt class="docutils literal"><span class="pre">--extras-<LANG>=</span></tt> for the specified
language. These option takes one-letter flag or long-name flag as a parameter
for specifying an extra.</p>
<p>The meaning of columns in output are as follows:</p>
<dl class="last docutils">
<dt>LETTER</dt>
<dd>One-letter flag. '<tt class="docutils literal">-</tt>' means the extra does not have one-letter flag.</dd>
<dt>NAME</dt>
<dd>Long-name flag. The long-name is used in <tt class="docutils literal">extras</tt> field.</dd>
<dt>ENABLED</dt>
<dd>Whether the extra is enabled or not. It takes <tt class="docutils literal">yes</tt> or <tt class="docutils literal">no</tt>.</dd>
<dt>LANGUAGE</dt>
<dd>The name of language if the extra is owned by a parser.
<tt class="docutils literal">NONE</tt> means the extra is common in parsers.</dd>
<dt>DESCRIPTION</dt>
<dd>Human readable description for the extra.</dd>
</dl>
</dd>
<dt><tt class="docutils literal"><span class="pre">--list-features</span></tt></dt>
<dd>Lists the compiled features.</dd>
<dt><tt class="docutils literal"><span class="pre">--list-fields[=(<language>|all)]</span></tt></dt>
<dd><p class="first">Lists the fields recognized for either the specified <em><language></em> or
<tt class="docutils literal">all</tt> languages. See "<a class="reference internal" href="#extension-fields">Extension fields</a>" subsection to know what are fields.
<tt class="docutils literal">all</tt> is used as default value if the option argument is omitted.</p>
<p>The meaning of columns are as follows:</p>
<dl class="last docutils">
<dt>LETTER</dt>
<dd>One-letter flag. '<tt class="docutils literal">-</tt>' means the field does not have one-letter flag.</dd>
<dt>NAME</dt>
<dd>Long-name of field.</dd>
<dt>ENABLED</dt>
<dd>Whether the field is enabled or not. It takes <tt class="docutils literal">yes</tt> or <tt class="docutils literal">no</tt>.</dd>
<dt>LANGUAGE</dt>
<dd>The name of language if the field is owned by a parser.
<tt class="docutils literal">NONE</tt> means that the field is a language-independent field which is
common in all languages.</dd>
<dt>JSTYPE</dt>
<dd>JSON type used in printing the value of field when <tt class="docutils literal"><span class="pre">--output-format=json</span></tt>
is specified. See ctags-client-tools(7).</dd>
<dt>FIXED</dt>
<dd><p class="first">Whether this field can be disabled or not in tags output.</p>
<p>Some fields are printed always in tags output.
They have <tt class="docutils literal">yes</tt> as the value for this column.</p>
<p class="last">Unlike the tag output mode, JSON output mode allows disabling
any fields.</p>
</dd>
<dt>OP</dt>
<dd>How this field can be accessed from optscript code.
This field is for Universal Ctags developers.</dd>
<dt>DESCRIPTION</dt>
<dd>Human readable description for the field.</dd>
</dl>
</dd>
<dt><tt class="docutils literal"><span class="pre">--list-kinds[=(<language>|all)]</span></tt></dt>
<dd><p class="first">Subset of <tt class="docutils literal"><span class="pre">--list-kinds-full</span></tt>. This option is kept for
backward-compatibility with Exuberant Ctags.</p>
<p>This option prints only LETTER, DESCRIPTION, and ENABLED fields
of <tt class="docutils literal"><span class="pre">--list-kinds-full</span></tt> output. However, the presentation of
ENABLED column is different from that of <tt class="docutils literal"><span class="pre">--list-kinds-full</span></tt>
option; <tt class="docutils literal">[off]</tt> follows after description if the kind is disabled,
and nothing follows if enabled. The most of all kinds are enabled
by default.</p>
<p>The critical weakness of this option is that this option does not
print the name of kind. Universal Ctags introduces
<tt class="docutils literal"><span class="pre">--list-kinds-full</span></tt> because it considers that names are
important.</p>
<p class="last">This option does not work with <tt class="docutils literal"><span class="pre">--machinable</span></tt> nor
<tt class="docutils literal"><span class="pre">--with-list-header</span></tt>.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--list-kinds-full[=(<language>|all)]</span></tt></dt>
<dd><p class="first">Lists the tag kinds recognized for either the specified <em><language></em>
or <tt class="docutils literal">all</tt> languages, and then exits. See "<a class="reference internal" href="#kinds">Kinds</a>" subsection to
learn what kinds are.
<tt class="docutils literal">all</tt> is used as default value if the option argument is omitted.</p>
<p>Each kind of tag recorded in the tag file is represented by a
one-letter flag, or a long-name flag. They are also used to filter the tags
placed into the output through use of the <tt class="docutils literal"><span class="pre">--kinds-<LANG></span></tt>
option.</p>
<p>The meaning of columns are as follows:</p>
<dl class="last docutils">
<dt>LANGUAGE</dt>
<dd>The name of language having the kind.</dd>
<dt>LETTER</dt>
<dd>One-letter flag. This must be unique in a language.</dd>
<dt>NAME</dt>
<dd>The long-name flag of the kind. This can be used as the alternative
to the one-letter flag described above. If enabling <tt class="docutils literal">K</tt> field with
<tt class="docutils literal"><span class="pre">--fields=+K</span></tt>, ctags uses long-names instead of
one-letters in tags output. To enable/disable a kind with
<tt class="docutils literal"><span class="pre">--kinds-<LANG></span></tt> option, long-name surrounded by braces instead
of one-letter. See "<a class="reference internal" href="#letters-and-names">Letters and names</a>" for details. This must be
unique in a language.</dd>
<dt>ENABLED</dt>
<dd>Whether the kind is enabled or not. It takes <tt class="docutils literal">yes</tt> or <tt class="docutils literal">no</tt>.</dd>
<dt>REFONLY</dt>
<dd>Whether the kind is specialized for reference tagging or not.
If the column is <tt class="docutils literal">yes</tt>, the kind is for reference tagging, and
it is never used for definition tagging. See also "<a class="reference internal" href="#id1">TAG ENTRIES</a>".</dd>
<dt>NROLES</dt>
<dd>The number of roles this kind has. See also "<a class="reference internal" href="#roles">Roles</a>".</dd>
<dt>MASTER</dt>
<dd><p class="first">The master parser controlling enablement of the kind.
A kind belongs to a language (owner) in Universal Ctags;
enabling and disabling a kind in a language has no effect on
a kind in another language even if both kinds has the
same one-letter flag and/or the same long-name flag. In other words,
the namespace of kinds are separated by language.</p>
<p>However, Exuberant Ctags does not separate the kinds of C and
C++. Enabling/disabling kindX in C language enables/disables a
kind in C++ language having the same long-name flag with kindX. To
emulate this behavior in Universal Ctags, a concept named
<em>master parser</em> is introduced. Enabling/disabling some kinds
are synchronized under the control of a master language.</p>
<pre class="code console literal-block">
<span class="generic prompt">$ </span>ctags --kinds-C<span class="operator">=</span>+<span class="literal string single">'{local}'</span> --list-kinds-full <span class="literal string escape">\
</span><span class="generic output"> | grep -E '^(#|C\+\+ .* local)'
</span><span class="generic prompt">#</span>LANGUAGE LETTER NAME ENABLED REFONLY NROLES MASTER DESCRIPTION
<span class="generic output">C++ l local yes no 0 C local variables
</span><span class="generic prompt">$ </span>ctags --kinds-C<span class="operator">=</span>-<span class="literal string single">'{local}'</span> --list-kinds-full <span class="literal string escape">\
</span><span class="generic output"> | grep -E '^(#|C\+\+ .* local)'
</span><span class="generic prompt">#</span>LANGUAGE LETTER NAME ENABLED REFONLY NROLES MASTER DESCRIPTION
<span class="generic output">C++ l local no no 0 C local variables</span>
</pre>
<p class="last">You see <tt class="docutils literal">ENABLED</tt> field of <tt class="docutils literal">local</tt> kind of C++ language is changed
Though <tt class="docutils literal">local</tt> kind of C language is enabled/disabled. If you swap the languages, you
see the same result.</p>
<!-- TODO: need a reference to "master parser" -->
</dd>
<dt>DESCRIPTION</dt>
<dd>Human readable description for the kind.</dd>
</dl>
</dd>
<dt><tt class="docutils literal"><span class="pre">--list-languages</span></tt></dt>
<dd><p class="first">Lists the names of the languages understood by ctags,
and then exits. These language names are case insensitive and may be
used in many other options like <tt class="docutils literal"><span class="pre">--language-force</span></tt>,
<tt class="docutils literal"><span class="pre">--languages</span></tt>, <tt class="docutils literal"><span class="pre">--kinds-<LANG></span></tt>, <tt class="docutils literal"><span class="pre">--regex-<LANG></span></tt>, and so on.</p>
<p>Each language listed is disabled if followed by <tt class="docutils literal">[disabled]</tt>.
To use the parser for such a language, specify the language as an
argument of <tt class="docutils literal"><span class="pre">--languages=+</span></tt> option.</p>
<p class="last"><tt class="docutils literal"><span class="pre">--machinable</span></tt> and <tt class="docutils literal"><span class="pre">--with-list-header</span></tt> options are ignored if they are
specified with this option.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--list-map-extensions[=(<language>|all)]</span></tt></dt>
<dd>Lists the file extensions which associate a file
name with a language for either the specified <em><language></em> or <tt class="docutils literal">all</tt>
languages, and then exits.
<tt class="docutils literal">all</tt> is used as default value if the option argument is omitted.</dd>
<dt><tt class="docutils literal"><span class="pre">--list-map-patterns[=(<language>|all)]</span></tt></dt>
<dd>Lists the file name patterns which associate a file
name with a language for either the specified <em><language></em> or <tt class="docutils literal">all</tt>
languages, and then exits.
<tt class="docutils literal">all</tt> is used as default value if the option argument is omitted.</dd>
<dt><tt class="docutils literal"><span class="pre">--list-maps[=(<language>|all)]</span></tt></dt>
<dd><p class="first">Lists file name patterns and the file extensions which associate a file
name with a language for either the specified <em><language></em> or <tt class="docutils literal">all</tt>
languages, and then exits.
<tt class="docutils literal">all</tt> is used as default value if the option argument is omitted.</p>
<p>To list the file extensions or file name patterns individually, use
<tt class="docutils literal"><span class="pre">--list-map-extensions</span></tt> or <tt class="docutils literal"><span class="pre">--list-map-patterns</span></tt> option.
See the <tt class="docutils literal"><span class="pre">--langmap</span></tt> option, and "<a class="reference internal" href="#determining-file-language">Determining file language</a>", above.</p>
<p class="last">This option does not work with <tt class="docutils literal"><span class="pre">--machinable</span></tt> nor
<tt class="docutils literal"><span class="pre">--with-list-header</span></tt>.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--list-mline-regex-flags</span></tt></dt>
<dd>Output list of flags which can be used in a multiline regex parser
definition.
See ctags-optlib(7).</dd>
<dt><tt class="docutils literal"><span class="pre">--list-params[=(<language>|all)]</span></tt></dt>
<dd>Lists the parameters for either the specified <em><language></em> or <tt class="docutils literal">all</tt>
languages, and then exits.
<tt class="docutils literal">all</tt> is used as default value if the option argument is omitted.</dd>
<dt><tt class="docutils literal"><span class="pre">--list-pseudo-tags</span></tt></dt>
<dd>Output list of pseudo-tags.</dd>
<dt><tt class="docutils literal"><span class="pre">--list-regex-flags</span></tt></dt>
<dd>Lists the flags that can be used in <tt class="docutils literal"><span class="pre">--regex-<LANG></span></tt> option.
See ctags-optlib(7).</dd>
<dt><tt class="docutils literal"><span class="pre">--list-roles[=(<language>|all)[.(<kind-specs>|*)]]</span></tt></dt>
<dd><p class="first">List the roles for either the specified <em><language></em> or <tt class="docutils literal">all</tt> languages.
<tt class="docutils literal">all</tt> is used as default value if the option argument is omitted.</p>
<p>If the parameter <em><kindspecs></em> is given after the parameter
<em><language></em> or <tt class="docutils literal">all</tt> with concatenating with '<tt class="docutils literal">.</tt>', list only roles
defined in the kinds. Both one-letter flags and long name flags surrounded
by braces are acceptable as the parameter <em><kindspecs></em>.</p>
<p>The meaning of columns are as follows:</p>
<dl class="last docutils">
<dt>LANGUAGE</dt>
<dd>The name of language having the role.</dd>
<dt>KIND(L/N)</dt>
<dd>The one-letter flag and the long-name flag of kind having the role.</dd>
<dt>NAME</dt>
<dd>The long-name flag of the role.</dd>
<dt>ENABLED</dt>
<dd>Whether the kind is enabled or not. It takes <tt class="docutils literal">yes</tt> or <tt class="docutils literal">no</tt>.</dd>
<dt>DESCRIPTION</dt>
<dd>Human readable description for the role.</dd>
</dl>
</dd>
<dt><tt class="docutils literal"><span class="pre">--list-subparsers[=(<baselang>|all)]</span></tt></dt>
<dd>Lists the subparsers for a base language for either the specified
<em><baselang></em> or <tt class="docutils literal">all</tt> languages, and then exits.
<tt class="docutils literal">all</tt> is used as default value if the option argument is omitted.</dd>
<dt><tt class="docutils literal"><span class="pre">--machinable[=(yes|no)]</span></tt></dt>
<dd>Use tab character as separators for <tt class="docutils literal"><span class="pre">--list-</span></tt> option output. It
may be suitable for scripting. See "<a class="reference internal" href="#list-options">List options</a>" for considered
use cases. Disabled by default.</dd>
<dt><tt class="docutils literal"><span class="pre">--with-list-header[=(yes|no)]</span></tt></dt>
<dd>Print headers describing columns in <tt class="docutils literal"><span class="pre">--list-</span></tt> option output.
See also "<a class="reference internal" href="#list-options">List options</a>".</dd>
</dl>
</div>
<div class="section" id="miscellaneous-options">
<span id="option-misc"></span><h2>Miscellaneous Options</h2>
<dl class="docutils">
<dt><tt class="docutils literal"><span class="pre">--help</span></tt></dt>
<dd>Prints to standard output a detailed usage description, and then exits.</dd>
<dt><tt class="docutils literal"><span class="pre">-?</span></tt></dt>
<dd>Equivalent to <tt class="docutils literal"><span class="pre">--help</span></tt>.</dd>
<dt><tt class="docutils literal"><span class="pre">--help-full</span></tt></dt>
<dd>Prints to standard output a detailed usage description including experimental
features, and then exits. Visit <a class="reference external" href="https://docs.ctags.io/">https://docs.ctags.io/</a> for information
about the latest exciting experimental features.</dd>
<dt><tt class="docutils literal"><span class="pre">--license</span></tt></dt>
<dd>Prints a summary of the software license to standard output, and then exits.</dd>
<dt><tt class="docutils literal"><span class="pre">--print-language</span></tt></dt>
<dd>Just prints the language parsers for specified source files, and then exits.</dd>
<dt><tt class="docutils literal"><span class="pre">--quiet[=(yes|no)]</span></tt></dt>
<dd>Write fewer messages (default is <tt class="docutils literal">no</tt>).</dd>
<dt><tt class="docutils literal"><span class="pre">--totals[=(yes|no|extra)]</span></tt></dt>
<dd><p class="first">Prints statistics about the source files read and the tag file written
during the current invocation of ctags. This option
is <tt class="docutils literal">no</tt> by default.</p>
<p class="last">The <tt class="docutils literal">extra</tt> value prints parser specific statistics for parsers
gathering such information.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">--verbose[=(yes|no)]</span></tt></dt>
<dd>Enable verbose mode. This prints out information on option processing
and a brief message describing what action is being taken for each file
considered by ctags. Normally, ctags
does not read command line arguments until after options are read
from the configuration files (see "<a class="reference internal" href="#files">FILES</a>", below).
However, if this option is the first argument on
the command line, it will take effect before any options are read from
these sources. The default is <tt class="docutils literal">no</tt>.</dd>
<dt><tt class="docutils literal"><span class="pre">-V</span></tt></dt>
<dd>Equivalent to <tt class="docutils literal"><span class="pre">--verbose</span></tt>.</dd>
<dt><tt class="docutils literal"><span class="pre">--version</span></tt></dt>
<dd>Prints a version identifier for ctags to standard
output, and then exits. This is guaranteed to always contain the string
"Universal Ctags".</dd>
</dl>
</div>
<div class="section" id="obsoleted-options">
<h2>Obsoleted Options</h2>
<p>These options are kept for backward-compatibility with Exuberant Ctags.</p>
<dl class="docutils">
<dt><tt class="docutils literal"><span class="pre">-w</span></tt></dt>
<dd>This option is silently ignored for backward-compatibility with the
ctags of SVR4 Unix.</dd>
<dt><tt class="docutils literal"><span class="pre">--file-scope[=(yes|no)]</span></tt></dt>
<dd>This options is removed. Use <tt class="docutils literal"><span class="pre">--extras=[+|-]F</span></tt> or
<tt class="docutils literal"><span class="pre">--extras=[+|-]{fileScope}</span></tt> instead.</dd>
<dt><tt class="docutils literal"><span class="pre">--extra=[+|-][<flags>|*]</span></tt></dt>
<dd>Equivalent to <tt class="docutils literal"><span class="pre">--extras=[+|-][<flags>|*]</span></tt>, which was introduced to make
the option naming convention align to the other options like
<tt class="docutils literal"><span class="pre">--kinds-<LANG>=</span></tt> and <tt class="docutils literal"><span class="pre">--fields=</span></tt>.</dd>
<dt><tt class="docutils literal"><span class="pre">--<LANG>-kinds=[+|-](<kinds>|*)</span></tt></dt>
<dd>This option is obsolete. Use <tt class="docutils literal"><span class="pre">--kinds-<LANG>=...</span></tt> instead.</dd>
</dl>
</div>
</div>
<div class="section" id="operational-details">
<h1>OPERATIONAL DETAILS</h1>
<p>As ctags considers each source file name in turn, it tries to
determine the language of the file by applying tests described in
"<a class="reference internal" href="#determining-file-language">Determining file language</a>".</p>
<p>If a language was identified, the file is opened and then the appropriate
language parser is called to operate on the currently open file. The parser
parses through the file and adds an entry to the tag file for each
language object it is written to handle. See "<a class="reference internal" href="#tag-file-format">TAG FILE FORMAT</a>", below,
for details on these entries.</p>
<div class="section" id="notes-for-c-c-parser">
<h2>Notes for C/C++ Parser</h2>
<!-- TODO: move the following description to parser-cxx.rst. -->
<p>This implementation of ctags imposes no formatting
requirements on C code as do legacy implementations. Older implementations
of ctags tended to rely upon certain formatting assumptions in order to
help it resolve coding dilemmas caused by preprocessor conditionals.</p>
<p>In general, ctags tries to be smart about conditional
preprocessor directives. If a preprocessor conditional is encountered
within a statement which defines a tag, ctags follows
only the first branch of that conditional (except in the special case of
<tt class="docutils literal">#if 0</tt>, in which case it follows only the last branch). The reason for
this is that failing to pursue only one branch can result in ambiguous
syntax, as in the following example:</p>
<pre class="code C literal-block">
<span class="comment preproc">#ifdef TWO_ALTERNATIVES
</span><span class="keyword">struct</span> <span class="punctuation">{</span>
<span class="comment preproc">#else
</span><span class="keyword">union</span> <span class="punctuation">{</span>
<span class="comment preproc">#endif
</span> <span class="keyword type">short</span> <span class="name">a</span><span class="punctuation">;</span>
<span class="keyword type">long</span> <span class="name">b</span><span class="punctuation">;</span>
<span class="punctuation">}</span>
</pre>
<p>Both branches cannot be followed, or braces become unbalanced and
ctags would be unable to make sense of the syntax.</p>
<p>If the application of this heuristic fails to properly parse a file,
generally due to complicated and inconsistent pairing within the
conditionals, ctags will retry the file using a
different heuristic which does not selectively follow conditional
preprocessor branches, but instead falls back to relying upon a closing
brace ('<tt class="docutils literal">}</tt>') in column 1 as indicating the end of a block once any brace
imbalance results from following a <tt class="docutils literal">#if</tt> conditional branch.</p>
<p>ctags will also try to specially handle arguments lists
enclosed in double sets of parentheses in order to accept the following
conditional construct:</p>
<pre class="literal-block">
extern void foo __ARGS((int one, char two));
</pre>
<p>Any name immediately preceding the '<tt class="docutils literal">((</tt>' will be automatically ignored and
the previous name will be used.</p>
<p>C++ operator definitions are specially handled. In order for consistency
with all types of operators (overloaded and conversion), the operator
name in the tag file will always be preceded by the string "operator "
(i.e. even if the actual operator definition was written as "operator<<").</p>
<p>After creating or appending to the tag file, it is sorted by the tag name,
removing identical tag lines.</p>
</div>
<div class="section" id="determining-file-language">
<span id="guessing"></span><h2>Determining file language</h2>
<div class="section" id="file-name-mapping">
<h3>File name mapping</h3>
<p>Unless the <tt class="docutils literal"><span class="pre">--language-force</span></tt> option is specified, the language of each source
file is automatically selected based upon a <em>mapping</em> of file names to
languages. The mappings in effect for each language may be displayed using
the <tt class="docutils literal"><span class="pre">--list-maps</span></tt> option and may be changed using the <tt class="docutils literal"><span class="pre">--langmap</span></tt> or
<tt class="docutils literal"><span class="pre">--map-<LANG></span></tt> options.</p>
<p>If the name of a file is not mapped to a language, ctags tries
to heuristically guess the language for the file by inspecting its content.</p>
<p>All files that have no file name mapping and no guessed parser are
ignored. This permits running ctags on all files in
either a single directory (e.g. "<tt class="docutils literal">ctags *</tt>"), or on
all files in an entire source directory tree
(e.g. "<tt class="docutils literal">ctags <span class="pre">-R</span></tt>"), since only those files whose
names are mapped to languages will be scanned.</p>
<p>An extension may be mapped to multiple parsers. For example, <tt class="docutils literal">.h</tt>
are mapped to C++, C and ObjectiveC. These mappings can cause
issues. ctags tries to select the proper parser
for the source file by applying heuristics to its content, however
it is not perfect. In case of issues one can use <tt class="docutils literal"><span class="pre">--language-force=<language></span></tt>,
<tt class="docutils literal"><span class="pre">--langmap=<map>[,<map>[...]]</span></tt>, or the <tt class="docutils literal"><span class="pre">--map-<LANG>=[+|-]<extension>|<pattern></span></tt>
options. (Some of the heuristics are applied whether <tt class="docutils literal"><span class="pre">--guess-language-eagerly</span></tt>
is given or not.)</p>
<!-- TODO: all heuristics??? To be confirmed. -->
</div>
<div class="section" id="heuristically-guessing">
<h3>Heuristically guessing</h3>
<p>If ctags cannot select a parser from the mapping of file names,
various heuristic tests are conducted to determine the language:</p>
<dl class="docutils">
<dt>template file name testing</dt>
<dd>If the file name has an <tt class="docutils literal">.in</tt> extension, ctags applies
the mapping to the file name without the extension. For example,
<tt class="docutils literal">config.h</tt> is tested for a file named <tt class="docutils literal">config.h.in</tt>.</dd>
<dt>"interpreter" testing</dt>
<dd><p class="first">The first line of the file is checked to see if the file is a <tt class="docutils literal">#!</tt>
script for a recognized language. ctags looks for
a parser having the same name.</p>
<p>If ctags finds no such parser,
ctags looks for the name in alias lists. For
example, consider if the first line is <tt class="docutils literal"><span class="pre">#!/bin/sh</span></tt>. Though
ctags has a "shell" parser, it doesn't have a "sh"
parser. However, <tt class="docutils literal">sh</tt> is listed as an alias for <tt class="docutils literal">shell</tt>, therefore
ctags selects the "shell" parser for the file.</p>
<p>An exception is <tt class="docutils literal">env</tt>. If <tt class="docutils literal">env</tt> is specified (for example
"<tt class="docutils literal"><span class="pre">#!/usr/bin/env</span> python</tt>"), ctags
reads more lines to find real interpreter specification.</p>
<p class="last">To display the list of aliases, use <tt class="docutils literal"><span class="pre">--list-aliases</span></tt> option.
To add an item to the list or to remove an item from the list, use the
<tt class="docutils literal"><span class="pre">--alias-<LANG>=+<pattern></span></tt> or <tt class="docutils literal"><span class="pre">--alias-<LANG>=-<pattern></span></tt> option
respectively.</p>
</dd>
<dt>"zsh autoload tag" testing</dt>
<dd>If the first line starts with <tt class="docutils literal">#compdef</tt> or <tt class="docutils literal">#autoload</tt>,
ctags regards the line as "zsh".</dd>
<dt>"emacs mode at the first line" testing</dt>
<dd><p class="first">The Emacs editor has multiple editing modes specialized for programming
languages. Emacs can recognize a marker called modeline in a file
and utilize the marker for the mode selection. This heuristic test does
the same as what Emacs does.</p>
<p>ctags treats <tt class="docutils literal">MODE</tt> as a name of interpreter and applies the same
rule of "interpreter" testing if the first line has one of
the following patterns:</p>
<pre class="literal-block">
-*- mode: MODE -*-
</pre>
<p>or</p>
<pre class="last literal-block">
-*- MODE -*-
</pre>
</dd>
<dt>"emacs mode at the EOF" testing</dt>
<dd><p class="first">Emacs editor recognizes another marker at the end of file as a
mode specifier. This heuristic test does the same as what Emacs does.</p>
<p>ctags treats <tt class="docutils literal">MODE</tt> as a name of an interpreter and applies the same
rule of "interpreter" heuristic testing, if the lines at the tail of the file
have the following pattern:</p>
<pre class="literal-block">
Local Variables:
...
mode: MODE
...
End:
</pre>
<p class="last">3000 characters are sought from the end of file to find the pattern.</p>
</dd>
<dt>"vim modeline" testing</dt>
<dd><p class="first">Like the modeline of the Emacs editor, Vim editor has the same concept.
ctags treats <tt class="docutils literal">TYPE</tt> as a name of interpreter and applies the same
rule of "interpreter" heuristic testing if the last 5 lines of the file
have one of the following patterns:</p>
<pre class="literal-block">
filetype=TYPE
</pre>
<p>or</p>
<pre class="last literal-block">
ft=TYPE
</pre>
</dd>
<dt>"PHP marker" testing</dt>
<dd>If the first line is started with <tt class="docutils literal"><span class="pre"><?php</span></tt>,
ctags regards the line as "php".</dd>
</dl>
<p>Looking into the file contents is a more expensive operation than file
name matching. So ctags runs the testings in limited
conditions. "interpreter" testing is enabled only when a file is an
executable or the <tt class="docutils literal"><span class="pre">--guess-language-eagerly</span></tt> (<tt class="docutils literal"><span class="pre">-G</span></tt> in short) option is
given. The other heuristic tests are enabled only when <tt class="docutils literal"><span class="pre">-G</span></tt> option is
given.</p>
<p>The <tt class="docutils literal"><span class="pre">--print-language</span></tt> option can be used just to print the results of
parser selections for given files instead of generating a tags file.</p>
<p>Examples:</p>
<pre class="code console literal-block">
<span class="generic prompt">$ </span>ctags --print-language config.h.in input.m input.unknown
<span class="generic output">config.h.in: C++
input.m: MatLab
input.unknown: NONE</span>
</pre>
<p><tt class="docutils literal">NONE</tt> means that ctags does not select any parser for the file.</p>
</div>
</div>
</div>
<div class="section" id="tag-file-format">
<h1>TAG FILE FORMAT</h1>
<p>This section describes the tag file format briefly. See tags(5) and
ctags-client-tools(7) for more details.</p>
<p>When not running in etags mode, each entry in the tag file consists of a
separate line, each looking like this, called <em>regular tags</em>, in the most general case:</p>
<pre class="literal-block">
<tag_name><TAB><file_name><TAB><ex_cmd>;"<TAB><extension_fields>
</pre>
<p>The fields and separators of these lines are specified as follows:</p>
<blockquote>
<ol class="arabic">
<li><p class="first"><tt class="docutils literal"><tag_name></tt>: tag name</p>
</li>
<li><p class="first"><tt class="docutils literal"><TAB></tt>: single tab character</p>
</li>
<li><p class="first"><tt class="docutils literal"><file_name></tt>: name of the file in which the object associated with the tag is located</p>
</li>
<li><p class="first"><tt class="docutils literal"><TAB></tt>: single tab character</p>
</li>
<li><p class="first"><tt class="docutils literal"><ex_cmd></tt>: EX command used to locate the tag within the file; generally a
search pattern (either <tt class="docutils literal">/pattern/</tt> or <tt class="docutils literal"><span class="pre">?pattern?</span></tt>) or line number (see
<tt class="docutils literal"><span class="pre">--excmd=<type></span></tt> option).</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">;"<TAB><extension_fields></span></tt>: a set of extension fields. See
"<a class="reference internal" href="#extension-fields">Extension fields</a>" for more details.</p>
<p>Tag file format 2 (see <tt class="docutils literal"><span class="pre">--format</span></tt>) extends the EX command
to include the extension fields embedded in an EX comment immediately appended
to the EX command, which leaves it backward-compatible with original
<tt class="docutils literal">vi(1)</tt> implementations.</p>
</li>
</ol>
</blockquote>
<p>A few special tags, called <em>pseudo tags</em>, are written into the tag file for internal purposes.</p>
<pre class="literal-block">
!_TAG_FILE_FORMAT 2 /extended format; --format=1 will not append ;" to lines/
!_TAG_FILE_SORTED 1 /0=unsorted, 1=sorted, 2=foldcase/
...
</pre>
<p><tt class="docutils literal"><span class="pre">--pseudo-tags=[+|-](<pseudo-tag>|*)</span></tt> option enables or disables emitting pseudo-tags.</p>
<p>See the output of "<tt class="docutils literal">ctags <span class="pre">--list-pseudo-tags</span></tt>" for the list of
the kinds.
See also tags(5) and ctags-client-tools(7) for more details of the pseudo tags.</p>
<p>These tags are composed in such a way that they always sort to the top of
the file. Therefore, the first two characters of these tags are used a magic
number to detect a tag file for purposes of determining whether a
valid tag file is being overwritten rather than a source file.</p>
<p>Note that the name of each source file will be recorded in the tag file
exactly as it appears on the command line. Therefore, if the path you
specified on the command line was relative to the current directory, then
it will be recorded in that same manner in the tag file. See, however,
the <tt class="docutils literal"><span class="pre">--tag-relative=(yes|no|always|never)</span></tt> option for how this behavior can be
modified.</p>
</div>
<div class="section" id="id1">
<span id="tag-entries"></span><h1>TAG ENTRIES</h1>
<p>A tag is an index for a language object. The concept of a tag and related
items in Exuberant Ctags are refined and extended in Universal Ctags.</p>
<p>A tag is categorized into <em>definition tags</em> or <em>reference tags</em>.
In general, Exuberant Ctags only tags <em>definitions</em> of
language objects: places where newly named language objects <em>are introduced</em>.
Universal Ctags, on the other hand, can also tag <em>references</em> of language
objects: places where named language objects <em>are used</em>. However, support
for generating reference tags is new and limited to specific areas of
specific languages in the current version.</p>
<div class="section" id="extension-fields">
<h2>Extension fields</h2>
<p>A tag can record various information, called <em>extension fields</em>.</p>
<p>Extension fields are tab-separated key-value pairs appended to the end of
the EX command as a comment, as described above. These key value pairs
appear in the general form <tt class="docutils literal">key:value</tt>.</p>
<p>In addition, information on the scope of the tag definition may be
available, with the key portion equal to some language-dependent construct
name and its value the name declared for that construct in the program.
This scope entry indicates the scope in which the tag was found.
For example, a tag generated for a C structure member would have a scope
looking like <tt class="docutils literal">struct:myStruct</tt>.</p>
<p><tt class="docutils literal"><span class="pre">--fields=[+|-][<flags>|*]</span></tt> and <tt class="docutils literal"><span class="pre">--fields-(<LANG>|all)=[+|-][<flags>|*]</span></tt> options specifies
which available extension fields are to be included in the tag entries.</p>
<p>See the output of "<tt class="docutils literal">ctags <span class="pre">--list-fields</span></tt>" for the list of
extension fields.
The essential fields are <tt class="docutils literal">name</tt>, <tt class="docutils literal">input</tt>, <tt class="docutils literal">pattern</tt>, and <tt class="docutils literal">line</tt>.
The meaning of major fields is as follows (long-name flag/one-letter flag):</p>
<dl class="docutils">
<dt><tt class="docutils literal">access</tt>/<tt class="docutils literal">a</tt></dt>
<dd>Indicates the visibility of this class member, where value is specific
to the language.</dd>
<dt><tt class="docutils literal">end</tt>/<tt class="docutils literal">e</tt></dt>
<dd>Indicates the line number of the end lines of the language object.</dd>
<dt><tt class="docutils literal">extras</tt>/<tt class="docutils literal">E</tt></dt>
<dd>Extra tag type information. See "<a class="reference internal" href="#extras">Extras</a>" for details.</dd>
<dt><tt class="docutils literal">file</tt>/<tt class="docutils literal">f</tt></dt>
<dd>Indicates that the tag has file-limited visibility. This key has no
corresponding value. Enabled by default.</dd>
<dt><tt class="docutils literal">implementation</tt>/<tt class="docutils literal">m</tt></dt>
<dd>When present, this indicates a limited implementation (abstract vs.
concrete) of a routine or class, where value is specific to the
language (<tt class="docutils literal">virtual</tt> or <tt class="docutils literal">pure virtual</tt> for C++; <tt class="docutils literal">abstract</tt> for Java).</dd>
<dt><tt class="docutils literal">inherits</tt>/<tt class="docutils literal">i</tt></dt>
<dd>When present, value is a comma-separated list of classes from which
this class is derived (i.e. inherits from).</dd>
<dt><tt class="docutils literal">input</tt>/<tt class="docutils literal">F</tt></dt>
<dd>The name of source file where <tt class="docutils literal">name</tt> is defined or referenced.</dd>
<dt><tt class="docutils literal">k</tt></dt>
<dd><a class="reference external" href="Kinds">Kind</a> of tag as one-letter. Enabled by default.
This field has no long-name.
See also <tt class="docutils literal">kind</tt>/<tt class="docutils literal">z</tt> flag.</dd>
<dt><tt class="docutils literal">K</tt></dt>
<dd><a class="reference external" href="Kinds">Kind</a> of tag as long-name.
This field has no long-name.
See also <tt class="docutils literal">kind</tt>/<tt class="docutils literal">z</tt> flag.</dd>
<dt><tt class="docutils literal">kind</tt>/<tt class="docutils literal">z</tt></dt>
<dd>Include the <tt class="docutils literal">kind:</tt> key in <a class="reference external" href="Kinds">kind field</a>. See also <tt class="docutils literal">k</tt> and <tt class="docutils literal">K</tt> flags.</dd>
<dt><tt class="docutils literal">language</tt>/<tt class="docutils literal">l</tt></dt>
<dd>Language of source file containing tag</dd>
<dt><tt class="docutils literal">line</tt>/<tt class="docutils literal">n</tt></dt>
<dd>The line number where <tt class="docutils literal">name</tt> is defined or referenced in <tt class="docutils literal">input</tt>.</dd>
<dt><tt class="docutils literal">name</tt>/<tt class="docutils literal">N</tt></dt>
<dd>The name of language objects.</dd>
<dt><tt class="docutils literal">pattern</tt>/<tt class="docutils literal">P</tt></dt>
<dd>Can be used to search the <tt class="docutils literal">name</tt> in <tt class="docutils literal">input</tt></dd>
<dt><tt class="docutils literal">roles</tt>/<tt class="docutils literal">r</tt></dt>
<dd>Roles assigned to the tag. See "<a class="reference internal" href="#roles">Roles</a>" for more details.</dd>
<dt><tt class="docutils literal">s</tt></dt>
<dd>Scope of tag definition. Enabled by default.
This field has no long-name.
See also <tt class="docutils literal">scope</tt>/<tt class="docutils literal">Z</tt> flag.</dd>
<dt><tt class="docutils literal">scope</tt>/<tt class="docutils literal">Z</tt></dt>
<dd>Prepend the <tt class="docutils literal">scope:</tt> key to scope (<tt class="docutils literal">s</tt>) field.
See also <tt class="docutils literal">s</tt> flag.</dd>
<dt><tt class="docutils literal">scopeKind</tt>/<tt class="docutils literal">p</tt></dt>
<dd>Kind of scope as long-name</dd>
<dt><tt class="docutils literal">signature</tt>/<tt class="docutils literal">S</tt></dt>
<dd>When present, value is a language-dependent representation of the
signature of a routine (e.g. prototype or parameter list). A routine signature in its complete form
specifies the return type of a routine and its formal argument list.
This extension field is presently supported only for C-based
languages and does not include the return type.</dd>
<dt><tt class="docutils literal">typeref</tt>/<tt class="docutils literal">t</tt></dt>
<dd>Type and name of a variable, typedef, or return type of
callable like function as <tt class="docutils literal">typeref:</tt> field.
Enabled by default.</dd>
</dl>
<div class="section" id="kinds">
<h3>Kinds</h3>
<p><tt class="docutils literal">kind</tt> is a field which represents the <em>kind</em> of language object
specified by a tag. Kinds used and defined are very different between
parsers. For example, C language defines <tt class="docutils literal">macro</tt>, <tt class="docutils literal">function</tt>,
<tt class="docutils literal">variable</tt>, <tt class="docutils literal">typedef</tt>, etc.</p>
<p><tt class="docutils literal"><span class="pre">--kinds-(<LANG>|all)=[+|-](<kinds>|*)</span></tt> option specifies a list of language-specific
kinds of tags (or kinds) to include in the output file for a particular
language.</p>
<p>See the output of "<tt class="docutils literal">ctags <span class="pre">--list-kinds-full</span></tt>" for the complete
list of the kinds.</p>
<p>Its value is either one of the
corresponding one-letter flags or a long-name flag. It is permitted
(and is, in fact, the default) for the key portion of this field to be
omitted. The optional behaviors are controlled with the <tt class="docutils literal"><span class="pre">--fields</span></tt> option as follows.</p>
<pre class="code console literal-block">
<span class="generic prompt">$ </span>ctags -o - kinds.c
<span class="generic output">foo kinds.c /^int foo() {$/;" f typeref:typename:int
</span><span class="generic prompt">$ </span>ctags --fields<span class="operator">=</span>+k -o - kinds.c
<span class="generic output">foo kinds.c /^int foo() {$/;" f typeref:typename:int
</span><span class="generic prompt">$ </span>ctags --fields<span class="operator">=</span>+K -o - kinds.c
<span class="generic output">foo kinds.c /^int foo() {$/;" function typeref:typename:int
</span><span class="generic prompt">$ </span>ctags --fields<span class="operator">=</span>+z -o - kinds.c
<span class="generic output">foo kinds.c /^int foo() {$/;" kind:f typeref:typename:int
</span><span class="generic prompt">$ </span>ctags --fields<span class="operator">=</span>+zK -o - kinds.c
<span class="generic output">foo kinds.c /^int foo() {$/;" kind:function typeref:typename:int</span>
</pre>
</div>
<div class="section" id="roles">
<h3>Roles</h3>
<p><em>Role</em> is a newly introduced concept in Universal Ctags. Role is a
concept associated with reference tags, and is not implemented widely yet.</p>
<p>As described previously in "<a class="reference internal" href="#kinds">Kinds</a>", the <tt class="docutils literal">kind</tt> field represents the type
of language object specified with a tag, such as a function vs. a variable.
Specific kinds are defined for reference tags, such as the C++ kind <tt class="docutils literal">header</tt> for
header file, or Java kind <tt class="docutils literal">package</tt> for package statements. For such reference
kinds, a <tt class="docutils literal">roles</tt> field can be added to distinguish the role of the reference
kind. In other words, the <tt class="docutils literal">kind</tt> field identifies the <em>what</em> of the language
object, whereas the <tt class="docutils literal">roles</tt> field identifies the <em>how</em> of a referenced language
object. Roles are only used with specific kinds.</p>
<p>For a definition tag, this field takes <tt class="docutils literal">def</tt> as a value.</p>
<p>For example, <tt class="docutils literal">Baz</tt> is tagged as a reference tag with kind <tt class="docutils literal">package</tt> and with
role <tt class="docutils literal">imported</tt> with the following code.</p>
<pre class="code java literal-block">
<span class="keyword namespace">package</span> <span class="name namespace">Bar</span><span class="punctuation">;</span>
<span class="keyword namespace">import</span> <span class="name namespace">Baz</span><span class="punctuation">;</span>
<span class="keyword declaration">class</span> <span class="name class">Foo</span> <span class="punctuation">{</span>
<span class="comment single">// ...
</span><span class="punctuation">}</span>
</pre>
<pre class="code console literal-block">
<span class="generic prompt">$ </span>ctags --fields<span class="operator">=</span>+KEr -uo - roles.java
<span class="generic output">Bar roles.java /^package Bar;$/;" package roles:def
Foo roles.java /^class Foo {$/;" class roles:def
</span><span class="generic prompt">$ </span>ctags --fields<span class="operator">=</span>+EKr --extras<span class="operator">=</span>+r -uo - roles.java
<span class="generic output">Bar roles.java /^package Bar;$/;" package roles:def
Baz roles.java /^import Baz;$/;" package roles:imported extras:reference
Foo roles.java /^class Foo {$/;" class roles:def</span>
</pre>
<p><tt class="docutils literal"><span class="pre">--roles-(<LANG>|all).(<kind>|all)=[+|-][<roles>|*]</span></tt> option specifies a list of kind-specific
roles of tags to include in the output file for a particular language.</p>
<p>Inquire the output of "<tt class="docutils literal">ctags <span class="pre">--list-roles</span></tt>" for the list of
roles.</p>
</div>
</div>
<div class="section" id="extras">
<h2>Extras</h2>
<p>Generally, ctags tags only language objects appearing
in source files, as is. In other words, a value for a <tt class="docutils literal">name:</tt> field
should be found on the source file associated with the <tt class="docutils literal">name:</tt>. An
<tt class="docutils literal">extra</tt> type tag (<em>extra</em>) is for tagging a language object with a processed
name, or for tagging something not associated with a language object. A typical
extra tag is <tt class="docutils literal">qualified</tt>, which tags a language object with a
class-qualified or scope-qualified name.</p>
<p><tt class="docutils literal"><span class="pre">--extras-(<LANG>|all)=[+|-][<flags>|*]</span></tt> option specifies
whether to include extra tag entries for certain kinds of information.</p>
<p>Inquire the output of <tt class="docutils literal">ctags <span class="pre">--list-extras</span></tt> for the list of extras.
The meaning of major extras is as follows (long-name flag/one-letter flag):</p>
<dl class="docutils">
<dt><tt class="docutils literal">anonymous</tt>/none</dt>
<dd><p class="first">Include an entry for the language object that has no name like lambda
function. This extra has no one-letter flag and is enabled by
default.</p>
<p>The extra tag is useful as a placeholder to fill scope fields
for language objects defined in a language object with no name.</p>
<pre class="code C literal-block">
<span class="keyword">struct</span> <span class="punctuation">{</span>
<span class="keyword type">double</span> <span class="name">x</span><span class="punctuation">,</span> <span class="name">y</span><span class="punctuation">;</span>
<span class="punctuation">}</span> <span class="name">p</span> <span class="operator">=</span> <span class="punctuation">{</span> <span class="punctuation">.</span><span class="name">x</span> <span class="operator">=</span> <span class="literal number float">0.0</span><span class="punctuation">,</span> <span class="punctuation">.</span><span class="name">y</span> <span class="operator">=</span> <span class="literal number float">0.0</span> <span class="punctuation">};</span>
</pre>
<p>'<tt class="docutils literal">x</tt>' and '<tt class="docutils literal">y</tt>' are the members of a structure. When filling the scope
fields for them, ctags has trouble because the struct
where '<tt class="docutils literal">x</tt>' and '<tt class="docutils literal">y</tt>' belong to has no name. For overcoming the trouble,
ctags generates an anonymous extra tag for the struct
and fills the scope fields with the name of the extra tag.</p>
<pre class="code console literal-block">
<span class="generic prompt">$ </span>ctags --fields<span class="operator">=</span>-f -uo - input.c
<span class="generic output">__anon9f26d2460108 input.c /^struct {$/;" s
x input.c /^ double x, y;$/;" m struct:__anon9f26d2460108
y input.c /^ double x, y;$/;" m struct:__anon9f26d2460108
p input.c /^} p = { .x = 0.0, .y = 0.0 };$/;" v typeref:struct:__anon9f26d2460108</span>
</pre>
<p class="last">The above tag output has <tt class="docutils literal">__anon9f26d2460108</tt> as an anonymous extra tag.
The typeref field of '<tt class="docutils literal">p</tt>' also receives the benefit of it.</p>
</dd>
<dt><tt class="docutils literal">fileScope</tt>/<tt class="docutils literal">F</tt></dt>
<dd><p class="first">Indicates whether tags scoped only for a single file (i.e. tags which
cannot be seen outside of the file in which they are defined, such as
language objects with <tt class="docutils literal">static</tt> modifier of C language) should be included
in the output. See also the <tt class="docutils literal"><span class="pre">-h</span></tt> option.</p>
<p>This extra tag is enabled by default. Add <tt class="docutils literal"><span class="pre">--extras=-F</span></tt> option not to
output tags scoped only for a single-file. This is the replacement for
<tt class="docutils literal"><span class="pre">--file-scope</span></tt> option of Exuberant Ctags.</p>
<pre class="code c literal-block">
<span class="keyword">static</span> <span class="keyword type">int</span> <span class="name function">f</span><span class="punctuation">()</span> <span class="punctuation">{</span>
<span class="keyword">return</span> <span class="literal number integer">0</span><span class="punctuation">;</span>
<span class="punctuation">}</span>
<span class="keyword type">int</span> <span class="name function">g</span><span class="punctuation">()</span> <span class="punctuation">{</span>
<span class="keyword">return</span> <span class="literal number integer">0</span><span class="punctuation">;</span>
<span class="punctuation">}</span>
</pre>
<pre class="code console last literal-block">
<span class="generic prompt">$ </span>ctags -uo - filescope.c
<span class="generic output">f filescope.c /^static int f() {$/;" f typeref:typename:int file:
g filescope.c /^int g() {$/;" f typeref:typename:int
</span><span class="generic prompt">$ </span>ctags --extras<span class="operator">=</span>-F -uo - filescope.c
<span class="generic output">g filescope.c /^int g() {$/;" f typeref:typename:int</span>
</pre>
</dd>
<dt><tt class="docutils literal">inputFile</tt>/<tt class="docutils literal">f</tt></dt>
<dd><p class="first">Include an entry for the base file name of every source file
(e.g. <tt class="docutils literal">example.c</tt>), which addresses the first line of the file.
This flag is the replacement for <tt class="docutils literal"><span class="pre">--file-tags</span></tt> hidden option of
Exuberant Ctags.</p>
<p>If the <tt class="docutils literal">end:</tt> field is enabled, the end line number of the file can be
attached to the tag. (However, ctags omits the <tt class="docutils literal">end:</tt> field
if no newline is in the file like an empty file.)</p>
<p>By default, ctags doesn't create the <tt class="docutils literal">inputFile</tt>/<tt class="docutils literal">f</tt> extra
tag for the source file when ctags doesn't find a parser
for it. Enabling <tt class="docutils literal">Unknown</tt> parser with <tt class="docutils literal"><span class="pre">--languages=+Unknown</span></tt> forces
ctags to create the extra tags for any source files.</p>
<p class="last">The etags mode enables the <tt class="docutils literal">Unknown</tt> parser implicitly.</p>
</dd>
<dt><tt class="docutils literal">pseudo</tt>/<tt class="docutils literal">p</tt></dt>
<dd>Include pseudo-tags. Enabled by default unless the tag file is
written to standard output. See ctags-client-tools(7) about
the detail of pseudo-tags.</dd>
<dt><tt class="docutils literal">qualified</tt>/<tt class="docutils literal">q</tt></dt>
<dd><p class="first">Include an extra class-qualified or namespace-qualified tag entry
for each tag which is a member of a class or a namespace.</p>
<p>This may allow easier location of a specific tags when
multiple occurrences of a tag name occur in the tag file.
Note, however, that this could potentially more than double
the size of the tag file.</p>
<p>The actual form of the qualified tag depends upon the language
from which the tag was derived (using a form that is most
natural for how qualified calls are specified in the
language). For C++ and Perl, it is in the form
<tt class="docutils literal"><span class="pre">class::member</span></tt>; for Eiffel and Java, it is in the form
<tt class="docutils literal">class.member</tt>.</p>
<p>Note: Using backslash characters as separators forming
qualified name in PHP. However, in tags output of
Universal Ctags, a backslash character in a name is escaped
with a backslash character. See tags(5) about the escaping.</p>
<p>The following example demonstrates the <tt class="docutils literal">qualified</tt> extra tag.</p>
<pre class="code Java literal-block">
<span class="keyword declaration">class</span> <span class="name class">point</span> <span class="punctuation">{</span>
<span class="keyword type">double</span> <span class="name">x</span><span class="punctuation">;</span>
<span class="punctuation">};</span>
</pre>
<p>For the above source file, ctags tags <tt class="docutils literal">point</tt> and <tt class="docutils literal">x</tt> by
default. If the <tt class="docutils literal">qualified</tt> extra is enabled from the command line
(<tt class="docutils literal"><span class="pre">--extras=+q</span></tt>), then <tt class="docutils literal">point.x</tt> is also tagged even though the string
"<tt class="docutils literal">point.x</tt>" is not in the source code.</p>
<pre class="code console last literal-block">
<span class="generic prompt">$ </span>ctags --fields<span class="operator">=</span>+K -uo - qualified.java
<span class="generic output">point qualified.java /^class point {$/;" class
x qualified.java /^ double x;$/;" field class:point
</span><span class="generic prompt">$ </span>ctags --fields<span class="operator">=</span>+K --extras<span class="operator">=</span>+q -uo - qualified.java
<span class="generic output">point qualified.java /^class point {$/;" class
x qualified.java /^ double x;$/;" field class:point
point.x qualified.java /^ double x;$/;" field class:point</span>
</pre>
</dd>
<dt><tt class="docutils literal">reference</tt>/<tt class="docutils literal">r</tt></dt>
<dd><p class="first">Include reference tags. See "<a class="reference internal" href="#id1">TAG ENTRIES</a>" about reference tags.</p>
<p>The following example demonstrates the <tt class="docutils literal">reference</tt> extra tag.</p>
<pre class="code c literal-block">
<span class="comment preproc">#include</span> <span class="comment preprocfile"><stdio.h></span><span class="comment preproc">
#include</span> <span class="comment preprocfile">"utils.h"</span><span class="comment preproc">
#define X
#undef X</span>
</pre>
<p>The <tt class="docutils literal">roles:system</tt> or <tt class="docutils literal">roles:local</tt> fields will be
added depending on whether the include file name begins with '<tt class="docutils literal"><</tt>' or not.</p>
<p>"<tt class="docutils literal">#define X</tt>" emits a definition tag. On the other hand "<tt class="docutils literal">#undef X</tt>" emits a
reference tag.</p>
<pre class="code console last literal-block">
<span class="generic prompt">$ </span>ctags --fields<span class="operator">=</span>+EKr -uo - inc.c
<span class="generic output">X inc.c /^#define X$/;" macro file: roles:def extras:fileScope
</span><span class="generic prompt">$ </span>ctags --fields<span class="operator">=</span>+EKr --extras<span class="operator">=</span>+r -uo - inc.c
<span class="generic output">stdio.h inc.c /^#include <stdio.h>/;" header roles:system extras:reference
utils.h inc.c /^#include "utils.h"/;" header roles:local extras:reference
X inc.c /^#define X$/;" macro file: roles:def extras:fileScope
X inc.c /^#undef X$/;" macro file: roles:undef extras:fileScope,reference</span>
</pre>
</dd>
</dl>
</div>
<div class="section" id="language-specific-fields-and-extras">
<h2>Language-specific fields and extras</h2>
<p>Exuberant Ctags has the concept of <em>fields</em> and <em>extras</em>. They are common
between parsers of different languages. Universal Ctags extends this concept
by providing language-specific fields and extras.</p>
<!-- Note: kinds are language-specific since e-ctags. roles are new to u-ctags. -->
<!-- TODO: move the following "Hot to ..." sections to FAQ man page when available -->
</div>
</div>
<div class="section" id="how-to-use-with-vi">
<h1>HOW TO USE WITH VI</h1>
<p><tt class="docutils literal">vi(1)</tt> will, by default, expect a tag file by the name <tt class="docutils literal">tags</tt> in the current
directory. Once the tag file is built, the following commands exercise
the tag indexing feature:</p>
<dl class="docutils">
<dt><tt class="docutils literal">vi <span class="pre">-t</span> tag</tt></dt>
<dd>Start vi and position the cursor at the file and line where <tt class="docutils literal">tag</tt>
is defined.</dd>
<dt><tt class="docutils literal">:ta tag</tt></dt>
<dd>Find a tag.</dd>
<dt><tt class="docutils literal"><span class="pre">Ctrl-]</span></tt></dt>
<dd>Find the tag under the cursor.</dd>
<dt><tt class="docutils literal"><span class="pre">Ctrl-T</span></tt></dt>
<dd>Return to previous location before jump to tag (not widely implemented).</dd>
</dl>
</div>
<div class="section" id="how-to-use-with-gnu-emacs">
<h1>HOW TO USE WITH GNU EMACS</h1>
<p><tt class="docutils literal">emacs(1)</tt> will, by default, expect a tag file by the name <tt class="docutils literal">TAGS</tt> in the
current directory. Once the tag file is built, the following commands
exercise the tag indexing feature:</p>
<dl class="docutils">
<dt><tt class="docutils literal"><span class="pre">M-x</span> <span class="pre">visit-tags-table</span> <RET> FILE <RET></tt></dt>
<dd>Select the tag file, <tt class="docutils literal">FILE</tt>, to use.</dd>
<dt><tt class="docutils literal"><span class="pre">M-.</span> [TAG] <RET></tt></dt>
<dd>Find the first definition of TAG. The default tag is the identifier
under the cursor.</dd>
<dt><tt class="docutils literal"><span class="pre">M-*</span></tt></dt>
<dd>Pop back to where you previously invoked <tt class="docutils literal"><span class="pre">M-.</span></tt>.</dd>
<dt><tt class="docutils literal"><span class="pre">C-u</span> <span class="pre">M-.</span></tt></dt>
<dd>Find the next definition for the last tag.</dd>
</dl>
<p>For more commands, see the Tags topic in the Emacs info document.</p>
</div>
<div class="section" id="how-to-use-with-nedit">
<h1>HOW TO USE WITH NEDIT</h1>
<p>NEdit version 5.1 and later can handle the new extended tag file format
(see <tt class="docutils literal"><span class="pre">--format</span></tt>).</p>
<ul class="simple">
<li>To make NEdit use the tag file, select "File->Load Tags File".</li>
<li>To jump to the definition for a tag, highlight the word, then press <tt class="docutils literal"><span class="pre">Ctrl-D</span></tt>.</li>
</ul>
<p>NEdit 5.1 can read multiple tag files from different
directories. Setting the X resource <tt class="docutils literal">nedit.tagFile</tt> to the name of a tag
file instructs NEdit to automatically load that tag file at startup time.</p>
</div>
<div class="section" id="caveats">
<h1>CAVEATS</h1>
<p>Because ctags is neither a preprocessor nor a compiler,
use of preprocessor macros can fool ctags into either
missing tags or improperly generating inappropriate tags. Although
ctags has been designed to handle certain common cases,
this is the single biggest cause of reported problems. In particular,
the use of preprocessor constructs which alter the textual syntax of C
can fool ctags. You can work around many such problems
by using the <tt class="docutils literal"><span class="pre">-I</span></tt> option.</p>
<p>Note that since ctags generates patterns for locating
tags (see the <tt class="docutils literal"><span class="pre">--excmd</span></tt> option), it is entirely possible that the wrong line
may be found by your editor if there exists another source line which is
identical to the line containing the tag. The following example
demonstrates this condition:</p>
<pre class="code C literal-block">
<span class="keyword type">int</span> <span class="name">variable</span><span class="punctuation">;</span>
<span class="comment multiline">/* ... */</span>
<span class="keyword type">void</span> <span class="name function">foo</span><span class="punctuation">(</span><span class="name">variable</span><span class="punctuation">)</span>
<span class="keyword type">int</span> <span class="name">variable</span><span class="punctuation">;</span>
<span class="punctuation">{</span>
<span class="comment multiline">/* ... */</span>
<span class="punctuation">}</span>
</pre>
<p>Depending upon which editor you use and where in the code you happen to be,
it is possible that the search pattern may locate the local parameter
declaration before it finds the actual global variable definition,
since the lines (and therefore their search patterns) are
identical.</p>
<p>This can be avoided by use of the <tt class="docutils literal"><span class="pre">--excmd=n</span></tt> option.</p>
</div>
<div class="section" id="bugs">
<h1>BUGS</h1>
<p>ctags has more options than <tt class="docutils literal">ls(1)</tt>.</p>
<p>ctags assumes the input file is written in the correct
grammar. Otherwise output of ctags is undefined. In other words it has garbage
in, garbage out (GIGO) feature.</p>
<!-- TODO: move the following paragraph to parser-cxx.rst. -->
<p>When parsing a C++ member function definition (e.g. <tt class="docutils literal"><span class="pre">className::function</span></tt>),
ctags cannot determine whether the scope specifier
is a class name or a namespace specifier and always lists it as a class name
in the scope portion of the extension fields. Also, if a C++ function
is defined outside of the class declaration (the usual case), the access
specification (i.e. public, protected, or private) and implementation
information (e.g. virtual, pure virtual) contained in the function
declaration are not known when the tag is generated for the function
definition. It will, however be available for prototypes (e.g. <tt class="docutils literal"><span class="pre">--kinds-c++=+p</span></tt>).</p>
<p>No qualified tags are generated for language objects inherited into a class.</p>
</div>
<div class="section" id="environment-variables">
<h1>ENVIRONMENT VARIABLES</h1>
<dl class="docutils">
<dt><tt class="docutils literal">TMPDIR</tt></dt>
<dd><p class="first">On Unix-like hosts where <tt class="docutils literal">mkstemp(3)</tt> is available, the value of this
variable specifies the directory in which to place temporary files.
This can be useful if the size of a temporary file becomes too large
to fit on the partition holding the default temporary directory
defined at compilation time.</p>
<p>ctags creates temporary
files only if either (1) an emacs-style tag file is being
generated, (2) the tag file is being sent to standard output, or
(3) the program was compiled to use an internal sort algorithm to sort
the tag files instead of the <tt class="docutils literal">sort(1)</tt> utility of the operating system.
If the <tt class="docutils literal">sort(1)</tt> utility of the operating system is being used, it will
generally observe this variable also.</p>
<p class="last">Note that if ctags
is setuid, the value of <tt class="docutils literal">TMPDIR</tt> will be ignored.</p>
</dd>
</dl>
</div>
<div class="section" id="files">
<h1>FILES</h1>
<dl class="docutils">
<dt><tt class="docutils literal">tags</tt></dt>
<dd>The default tag file created by ctags.</dd>
<dt><tt class="docutils literal">TAGS</tt></dt>
<dd>The default tag file created by etags.</dd>
</dl>
<p><tt class="docutils literal"><span class="pre">$XDG_CONFIG_HOME/ctags/*.ctags</span></tt>, or <tt class="docutils literal"><span class="pre">$HOME/.config/ctags/*.ctags</span></tt> if
<tt class="docutils literal">$XDG_CONFIG_HOME</tt> is not defined
(on other than MS Windows)</p>
<p><tt class="docutils literal"><span class="pre">$HOME/.ctags.d/*.ctags</span></tt></p>
<p><tt class="docutils literal"><span class="pre">$HOMEDRIVE$HOMEPATH/ctags.d/*.ctags</span></tt> (on MS Windows only)</p>
<p><tt class="docutils literal"><span class="pre">.ctags.d/*.ctags</span></tt></p>
<p><tt class="docutils literal"><span class="pre">ctags.d/*.ctags</span></tt></p>
<blockquote>
<p>If any of these configuration files exist, each will be expected to
contain a set of default options which are read in the order listed
when ctags starts, but before any command line options
are read. This makes it possible to set up personal or project-level defaults.</p>
<p>It
is possible to compile ctags to read an additional
configuration file before any of those shown above, which will be
indicated if the output produced by the <tt class="docutils literal"><span class="pre">--version</span></tt> option lists the
<tt class="docutils literal"><span class="pre">custom-conf</span></tt> feature.</p>
<p>Options appearing on the command line will override options
specified in these files. Only options will be read from these
files.</p>
<p>Note that the option
files are read in line-oriented mode in which spaces are significant
(since shell quoting is not possible) but spaces at the beginning
of a line are ignored. Each line of the file is read as
one command line parameter (as if it were quoted with single quotes).
Therefore, use new lines to indicate separate command-line arguments.</p>
<p>A line starting with '<tt class="docutils literal">#</tt>' is treated as a comment.</p>
<p><tt class="docutils literal">*.ctags</tt> files in a directory are loaded in alphabetical order.</p>
</blockquote>
</div>
<div class="section" id="see-also">
<h1>SEE ALSO</h1>
<p>See ctags-optlib(7) for defining (or extending) a parser
in a configuration file.</p>
<p>See tags(5) for the format of tag files.</p>
<p>See ctags-incompatibilities(7) about known incompatible changes
with Exuberant Ctags.</p>
<p>See ctags-client-tools(7) if you are interested in writing
a tool for processing tags files.</p>
<p>See ctags-lang-python(7) about python input specific notes.</p>
<p>See readtags(1) about a client tool for binary searching a
name in a sorted tags file.</p>
<p>The official Universal Ctags web site at: <a class="reference external" href="https://ctags.io/">https://ctags.io/</a></p>
<p>Also <tt class="docutils literal">ex(1)</tt>, <tt class="docutils literal">vi(1)</tt>, <tt class="docutils literal">elvis(1)</tt>, or, better yet, <tt class="docutils literal">vim(1)</tt>, the official editor of ctags.
For more information on <tt class="docutils literal">vim(1)</tt>, see the Vim web site at: <a class="reference external" href="https://www.vim.org/">https://www.vim.org/</a></p>
</div>
<div class="section" id="author">
<h1>AUTHOR</h1>
<p>Universal Ctags project
<a class="reference external" href="https://ctags.io/">https://ctags.io/</a></p>
<p>Darren Hiebert <<a class="reference external" href="mailto:dhiebert@users.sourceforge.net">dhiebert@users.sourceforge.net</a>>
<a class="reference external" href="http://DarrenHiebert.com/">http://DarrenHiebert.com/</a></p>
</div>
<div class="section" id="motivation">
<h1>MOTIVATION</h1>
<p>"Think ye at all times of rendering some service to every member of the
human race."</p>
<p>"All effort and exertion put forth by man from the fullness of his heart is
worship, if it is prompted by the highest motives and the will to do
service to humanity."</p>
<p>-- From the Baha'i Writings</p>
</div>
<div class="section" id="credits">
<h1>CREDITS</h1>
<p>This version of ctags (Universal Ctags) derived from
the repository, known as fishman-ctags, started by Reza Jelveh.</p>
<p>The fishman-ctags was derived from Exuberant Ctags.</p>
<p>Some parsers are taken from <tt class="docutils literal">tagmanager</tt> of the Geany (<a class="reference external" href="https://www.geany.org/">https://www.geany.org/</a>)
project.</p>
<p>Exuberant Ctags was originally derived from and
inspired by the ctags program by Steve Kirkendall <<a class="reference external" href="mailto:kirkenda@cs.pdx.edu">kirkenda@cs.pdx.edu</a>>
that comes with the Elvis vi clone (though virtually none of the original
code remains).</p>
<p>Credit is also due Bram Moolenaar <<a class="reference external" href="mailto:Bram@vim.org">Bram@vim.org</a>>, the author of vim,
who has devoted so much of his time and energy both to developing the editor
as a service to others, and to helping the orphans of Uganda.</p>
<p>The section entitled "<a class="reference internal" href="#how-to-use-with-gnu-emacs">HOW TO USE WITH GNU EMACS</a>" was shamelessly stolen
from the info page for GNU etags.</p>
</div>
</div>
</body>
</html>
|
