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 .