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diff --git a/coreutils-5.3.0-bin/man/cat1p/ln.1p.txt b/coreutils-5.3.0-bin/man/cat1p/ln.1p.txt new file mode 100644 index 0000000..6e32c61 --- /dev/null +++ b/coreutils-5.3.0-bin/man/cat1p/ln.1p.txt @@ -0,0 +1,265 @@ +ln(P) ln(P) + + + + + +NAME + ln - link files + +SYNOPSIS + ln [-fs] source_file target_file + + ln [-fs] source_file ... target_dir + + +DESCRIPTION + In the first synopsis form, the ln utility shall create + a new directory entry (link) at the destination path + specified by the target_file operand. If the -s option + is specified, a symbolic link shall be created for the + file specified by the source_file operand. This first + synopsis form shall be assumed when the final operand + does not name an existing directory; if more than two + operands are specified and the final is not an existing + directory, an error shall result. + + In the second synopsis form, the ln utility shall create + a new directory entry (link), or if the -s option is + specified a symbolic link, for each file specified by a + source_file operand, at a destination path in the exist- + ing directory named by target_dir. + + If the last operand specifies an existing file of a type + not specified by the System Interfaces volume of + IEEE Std 1003.1-2001, the behavior is implementation- + defined. + + The corresponding destination path for each source_file + shall be the concatenation of the target directory path- + name, a slash character, and the last pathname component + of the source_file. The second synopsis form shall be + assumed when the final operand names an existing direc- + tory. + + For each source_file: + + If the destination path exists: <ol type="a"> + + If the -f option is not specified, ln shall write a + diagnostic message to standard error, do nothing more + with the current source_file, and go on to any remaining + source_files. + + Actions shall be performed equivalent to the unlink() + function defined in the System Interfaces volume of + IEEE Std 1003.1-2001, called using destination as the + path argument. If this fails for any reason, ln shall + write a diagnostic message to standard error, do nothing + more with the current source_file, and go on to any + remaining source_files. + + If the -s option is specified, ln shall create a sym- + bolic link named by the destination path and containing + as its pathname source_file. The ln utility shall do + nothing more with source_file and shall go on to any + remaining files. + + If source_file is a symbolic link, actions shall be per- + formed equivalent to the link() function using the + object that source_file references as the path1 argument + and the destination path as the path2 argument. The ln + utility shall do nothing more with source_file and shall + go on to any remaining files. + + Actions shall be performed equivalent to the link() + function defined in the System Interfaces volume of + IEEE Std 1003.1-2001 using source_file as the path1 + argument, and the destination path as the path2 argu- + ment. + +OPTIONS + The ln utility shall conform to the Base Definitions + volume of IEEE Std 1003.1-2001, Section 12.2, Utility + Syntax Guidelines. + + The following option shall be supported: + + -f Force existing destination pathnames to be + removed to allow the link. + + -s Create symbolic links instead of hard links. + + +OPERANDS + The following operands shall be supported: + + source_file + A pathname of a file to be linked. If the -s + option is specified, no restrictions on the type + of file or on its existence shall be made. If the + -s option is not specified, whether a directory + can be linked is implementation-defined. + + target_file + The pathname of the new directory entry to be + created. + + target_dir + A pathname of an existing directory in which the + new directory entries are created. + + +STDIN + Not used. + +INPUT FILES + None. + +ENVIRONMENT VARIABLES + The following environment variables shall affect the + execution of ln: + + LANG Provide a default value for the internationaliza- + tion variables that are unset or null. (See the + Base Definitions volume of IEEE Std 1003.1-2001, + Section 8.2, Internationalization Variables for + the precedence of internationalization variables + used to determine the values of locale cate- + gories.) + + LC_ALL If set to a non-empty string value, override the + values of all the other internationalization + variables. + + LC_CTYPE + Determine the locale for the interpretation of + sequences of bytes of text data as characters + (for example, single-byte as opposed to multi- + byte characters in arguments). + + LC_MESSAGES + Determine the locale that should be used to + affect the format and contents of diagnostic mes- + sages written to standard error. + + NLSPATH + Determine the location of message catalogs for + the processing of LC_MESSAGES . + + +ASYNCHRONOUS EVENTS + Default. + +STDOUT + Not used. + +STDERR + The standard error shall be used only for diagnostic + messages. + +OUTPUT FILES + None. + +EXTENDED DESCRIPTION + None. + +EXIT STATUS + The following exit values shall be returned: + + 0 All the specified files were linked successfully. + + >0 An error occurred. + + +CONSEQUENCES OF ERRORS + Default. + + The following sections are informative. + +APPLICATION USAGE + None. + +EXAMPLES + None. + +RATIONALE + Some historic versions of ln (including the one speci- + fied by the SVID) unlink the destination file, if it + exists, by default. If the mode does not permit writing, + these versions prompt for confirmation before attempting + the unlink. In these versions the -f option causes ln + not to attempt to prompt for confirmation. + + This allows ln to succeed in creating links when the + target file already exists, even if the file itself is + not writable (although the directory must be). Early + proposals specified this functionality. + + This volume of IEEE Std 1003.1-2001 does not allow the + ln utility to unlink existing destination paths by + default for the following reasons: + + The ln utility has historically been used to pro- + vide locking for shell applications, a usage that + is incompatible with ln unlinking the destination + path by default. There was no corresponding tech- + nical advantage to adding this functionality. + + This functionality gave ln the ability to destroy + the link structure of files, which changes the + historical behavior of ln. + + This functionality is easily replicated with a + combination of rm and ln. + + It is not historical practice in many systems; + BSD and BSD-derived systems do not support this + behavior. Unfortunately, whichever behavior is + selected can cause scripts written expecting the + other behavior to fail. + + It is preferable that ln perform in the same man- + ner as the link() function, which does not permit + the target to exist already. + + This volume of IEEE Std 1003.1-2001 retains the -f + option to provide support for shell scripts depending on + the SVID semantics. It seems likely that shell scripts + would not be written to handle prompting by ln and would + therefore have specified the -f option. + + The -f option is an undocumented feature of many histor- + ical versions of the ln utility, allowing linking to + directories. These versions require modification. + + Early proposals of this volume of IEEE Std 1003.1-2001 + also required a -i option, which behaved like the -i + options in cp and mv, prompting for confirmation before + unlinking existing files. This was not historical prac- + tice for the ln utility and has been omitted. + +FUTURE DIRECTIONS + None. + +SEE ALSO + chmod() , find , pax , rm , the System Interfaces volume + of IEEE Std 1003.1-2001, link(), unlink() + +COPYRIGHT + Portions of this text are reprinted and reproduced in + electronic form from IEEE Std 1003.1, 2003 Edition, + Standard for Information Technology -- Portable Operat- + ing System Interface (POSIX), The Open Group Base Speci- + fications Issue 6, Copyright (C) 2001-2003 by the Insti- + tute of Electrical and Electronics Engineers, Inc and + The Open Group. In the event of any discrepancy between + this version and the original IEEE and The Open Group + Standard, the original IEEE and The Open Group Standard + is the referee document. The original Standard can be + obtained online at http://www.open- + group.org/unix/online.html . + + + +POSIX 2003 ln(P) |