Ubuntu Manpage: rm - remove directory entries

NAME

       rm - remove directory entries

SYNOPSIS

       rm [-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 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 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 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.

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 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 current file used as the path argument.

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 Variables 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 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 affirmative 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
       sections. 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
       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 implementations may desire more descriptive prompts than those used on
historical 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 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, however, the -f option suppresses usage messages and system errors as well.
Suppressing such messages 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. Historical 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 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
dependence on the unlink() functionality, per the DESCRIPTION. When removing hierarchies with -r or -R,
the prohibition on following symbolic links has to be made explicit.

FUTURE DIRECTIONS

       None.

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)