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|
rm(P) rm(P)
NAME
rm - remove directory entries
SYNOPSIS
rm [-fiRr] file...
DESCRIPTION
The rm utility shall remove the directory entry speci-
fied by each file argument.
If either of the files dot or dot-dot are specified as
the basename portion of an operand (that is, the final
pathname component), rm shall write a diagnostic message
to standard error and do nothing more with such oper-
ands.
For each file the following steps shall be taken:
If the file does not exist: <ol type="a">
If the -f option is not specified, rm shall write a
diagnostic message to standard error.
Go on to any remaining files.
If file is of type directory, the following steps shall
be taken: <ol type="a">
If neither the -R option nor the -r option is specified,
rm shall write a diagnostic message to standard error,
do nothing more with file, and go on to any remaining
files.
If the -f option is not specified, and either the per-
missions of file do not permit writing and the standard
input is a terminal or the -i option is specified, rm
shall write a prompt to standard error and read a line
from the standard input. If the response is not affirma-
tive, rm shall do nothing more with the current file and
go on to any remaining files.
For each entry contained in file, other than dot or dot-
dot, the four steps listed here (1 to 4) shall be taken
with the entry as if it were a file operand. The rm
utility shall not traverse directories by following sym-
bolic links into other parts of the hierarchy, but shall
remove the links themselves.
If the -i option is specified, rm shall write a prompt
to standard error and read a line from the standard
input. If the response is not affirmative, rm shall do
nothing more with the current file, and go on to any
remaining files.
If file is not of type directory, the -f option is not
specified, and either the permissions of file do not
permit writing and the standard input is a terminal or
the -i option is specified, rm shall write a prompt to
the standard error and read a line from the standard
input. If the response is not affirmative, rm shall do
nothing more with the current file and go on to any
remaining files.
If the current file is a directory, rm shall perform
actions equivalent to the rmdir() function defined in
the System Interfaces volume of IEEE Std 1003.1-2001
called with a pathname of the current file used as the
path argument. If the current file is not a directory,
rm shall perform actions equivalent to the unlink()
function defined in the System Interfaces volume of
IEEE Std 1003.1-2001 called with a pathname of the cur-
rent file used as the path argument.
If this fails for any reason, rm shall write a diagnos-
tic message to standard error, do nothing more with the
current file, and go on to any remaining files.
The rm utility shall be able to descend to arbitrary
depths in a file hierarchy, and shall not fail due to
path length limitations (unless an operand specified by
the user exceeds system limitations).
OPTIONS
The rm utility shall conform to the Base Definitions
volume of IEEE Std 1003.1-2001, Section 12.2, Utility
Syntax Guidelines.
The following options shall be supported:
-f Do not prompt for confirmation. Do not write
diagnostic messages or modify the exit status in
the case of nonexistent operands. Any previous
occurrences of the -i option shall be ignored.
-i Prompt for confirmation as described previously.
Any previous occurrences of the -f option shall
be ignored.
-R Remove file hierarchies. See the DESCRIPTION.
-r Equivalent to -R.
OPERANDS
The following operand shall be supported:
file A pathname of a directory entry to be removed.
STDIN
The standard input shall be used to read an input line
in response to each prompt specified in the STDOUT sec-
tion. Otherwise, the standard input shall not be used.
INPUT FILES
None.
ENVIRONMENT VARIABLES
The following environment variables shall affect the
execution of rm:
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_COLLATE
Determine the locale for the behavior of ranges,
equivalence classes, and multi-character collat-
ing elements used in the extended regular expres-
sion defined for the yesexpr locale keyword in
the LC_MESSAGES category.
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) and the behavior of
character classes within regular expressions used
in the extended regular expression defined for
the yesexpr locale keyword in the LC_MESSAGES
category.
LC_MESSAGES
Determine the locale for the processing of affir-
mative responses that should be used to affect
the format and contents of diagnostic messages
written to standard error.
NLSPATH
Determine the location of message catalogs for
the processing of LC_MESSAGES .
ASYNCHRONOUS EVENTS
Default.
STDOUT
Not used.
STDERR
Prompts shall be written to standard error under the
conditions specified in the DESCRIPTION and OPTIONS sec-
tions. The prompts shall contain the file pathname, but
their format is otherwise unspecified. The standard
error also shall be used for diagnostic messages.
OUTPUT FILES
None.
EXTENDED DESCRIPTION
None.
EXIT STATUS
The following exit values shall be returned:
0 All of the named directory entries for which rm
performed actions equivalent to the rmdir() or
unlink() functions were removed.
>0 An error occurred.
CONSEQUENCES OF ERRORS
Default.
The following sections are informative.
APPLICATION USAGE
The rm utility is forbidden to remove the names dot and
dot-dot in order to avoid the consequences of inadver-
tently doing something like:
rm -r .*
Some implementations do not permit the removal of the
last link to an executable binary file that is being
executed; see the [EBUSY] error in the unlink() function
defined in the System Interfaces volume of
IEEE Std 1003.1-2001. Thus, the rm utility can fail to
remove such files.
The -i option causes rm to prompt and read the standard
input even if the standard input is not a terminal, but
in the absence of -i the mode prompting is not done when
the standard input is not a terminal.
EXAMPLES
The following command:
rm a.out core
removes the directory entries: a.out and core.
The following command:
rm -Rf junk
removes the directory junk and all its contents, without
prompting.
RATIONALE
For absolute clarity, paragraphs (2b) and (3) in the
DESCRIPTION of rm describing the behavior when prompting
for confirmation, should be interpreted in the following
manner:
if ((NOT f_option) AND
((not_writable AND input_is_terminal) OR i_option))
The exact format of the interactive prompts is unspeci-
fied. Only the general nature of the contents of prompts
are specified because implementations may desire more
descriptive prompts than those used on historical imple-
mentations. Therefore, an application not using the -f
option, or using the -i option, relies on the system to
provide the most suitable dialog directly with the user,
based on the behavior specified.
The -r option is historical practice on all known sys-
tems. The synonym -R option is provided for consistency
with the other utilities in this volume of
IEEE Std 1003.1-2001 that provide options requesting
recursive descent through the file hierarchy.
The behavior of the -f option in historical versions of
rm is inconsistent. In general, along with "forcing" the
unlink without prompting for permission, it always
causes diagnostic messages to be suppressed and the exit
status to be unmodified for nonexistent operands and
files that cannot be unlinked. In some versions, how-
ever, the -f option suppresses usage messages and system
errors as well. Suppressing such messages is not a ser-
vice to either shell scripts or users.
It is less clear that error messages regarding files
that cannot be unlinked (removed) should be suppressed.
Although this is historical practice, this volume of
IEEE Std 1003.1-2001 does not permit the -f option to
suppress such messages.
When given the -r and -i options, historical versions of
rm prompt the user twice for each directory, once before
removing its contents and once before actually attempt-
ing to delete the directory entry that names it. This
allows the user to "prune" the file hierarchy walk. His-
torical versions of rm were inconsistent in that some
did not do the former prompt for directories named on
the command line and others had obscure prompting behav-
ior when the -i option was specified and the permissions
of the file did not permit writing. The POSIX Shell and
Utilities rm differs little from historic practice, but
does require that prompts be consistent. Historical ver-
sions of rm were also inconsistent in that prompts were
done to both standard output and standard error. This
volume of IEEE Std 1003.1-2001 requires that prompts be
done to standard error, for consistency with cp and mv,
and to allow historical extensions to rm that provide an
option to list deleted files on standard output.
The rm utility is required to descend to arbitrary
depths so that any file hierarchy may be deleted. This
means, for example, that the rm utility cannot run out
of file descriptors during its descent (that is, if the
number of file descriptors is limited, rm cannot be
implemented in the historical fashion where one file
descriptor is used per directory level). Also, rm is not
permitted to fail because of path length restrictions,
unless an operand specified by the user is longer than
{PATH_MAX}.
The rm utility removes symbolic links themselves, not
the files they refer to, as a consequence of the depen-
dence on the unlink() functionality, per the DESCRIP-
TION. When removing hierarchies with -r or -R, the pro-
hibition on following symbolic links has to be made
explicit.
FUTURE DIRECTIONS
None.
SEE ALSO
rmdir() , the System Interfaces volume of
IEEE Std 1003.1-2001, remove(), rmdir(), 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 rm(P)
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