RM(P) POSIX Programmer's Manual RM(P)NAMErm - remove directory entries
SYNOPSISrm [-fiRr] file...
DESCRIPTION
The rm utility shall remove the directory entry specified 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 operands.
For each file the following steps shall be taken:
1. If the file does not exist:
a. If the -f option is not specified, rm shall write a diagnostic
message to standard error.
b. Go on to any remaining files.
2. If file is of type directory, the following steps shall be taken:
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.
b. If the -f option is not specified, and either the permissions
of file do not permit writing and the standard input is a ter‐
minal 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 affirmative, rm shall do nothing more with the
current file and go on to any remaining files.
c. 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 symbolic links into other
parts of the hierarchy, but shall remove the links themselves.
d. If the -i option is specified, rm shall write a prompt to stan‐
dard 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.
3. 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.
4. If the current file is a directory, rm shall perform actions equiv‐
alent to the rmdir() function defined in the System Interfaces vol‐
ume 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 direc‐
tory, 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 current file used as the path argu‐
ment.
If this fails for any reason, rm shall write a diagnostic 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 section. 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 internationalization variables
that are unset or null. (See the Base Definitions volume of
IEEE Std 1003.1-2001, Section 8.2, Internationalization Vari‐
ables for the precedence of internationalization variables used
to determine the values of locale categories.)
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 collating elements used in the
extended regular expression defined for the yesexpr locale key‐
word 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 key‐
word in the LC_MESSAGES category.
LC_MESSAGES
Determine the locale for the processing of affirmative responses
that should be used to affect the format and contents of diag‐
nostic 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 speci‐
fied in the DESCRIPTION and OPTIONS sections. The prompts shall contain
the file pathname, but their format is otherwise unspecified. The stan‐
dard 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 inadvertently 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
1. The following command:
rm a.out core
removes the directory entries: a.out and core.
2. 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 unspecified. Only the
general nature of the contents of prompts are specified because imple‐
mentations may desire more descriptive prompts than those used on his‐
torical implementations. 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 systems. 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 recur‐
sive descent through the file hierarchy.
The behavior of the -f option in historical versions of rm is inconsis‐
tent. 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, however, the -f option sup‐
presses usage messages and system errors as well. Suppressing such mes‐
sages is not a service 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 attempting 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 behavior 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 versions of rm were also incon‐
sistent 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 direc‐
tory 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 dependence on the unlink() function‐
ality, per the DESCRIPTION. When removing hierarchies with -r or -R,
the prohibition on following symbolic links has to be made explicit.
FUTURE DIRECTIONS
None.
SEE ALSOrmdir() , 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 Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute 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.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 RM(P)
