STANDARD INPUT

Used to read an input line in response to each prompt specified in STANDARD OUTPUT . Otherwise, the standard input shall not be used.

INPUT FILES

None.

ENVIRONMENT VARIABLES

The following environment variables shall affect the execution of rm:

LANG

This variable shall determine the locale to use for the locale categories when both LC_ALL and the corresponding environment variable (beginning with LC_ ) do not specify a locale. See 2.6.

LC_ALL

This variable shall determine the locale to be used to override any values for locale categories specified by the settings of LANG or any environment variables beginning with LC_.

LC_COLLATE

This variable shall determine the locale for the behavior of ranges, equivalence classes, and multicharacter collating elements used in the extended regular expression defined for the yesexpr locale keyword in the LC_MESSAGES category.

LC_CTYPE

This variable shall determine the locale for the interpretation of sequences of bytes of text data as characters (e.g., single- versus multibyte 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

This variable shall determine the processing of affirmative responses and the language in which messages should be written.

ASYNCHRONOUS EVENTS

Default.

STANDARD OUTPUT

None.

STANDARD ERROR

Prompts shall be written to standard error under the conditions specified in

OUTPUT FILES

None.

EXAMPLES

The SVID requires that systems do not permit the removal of the last link to an executable binary file that is being executed. 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.

For absolute clarity, paragraphs (2)(b) and (3) in AND 4.53.3. THE PROMPTS SHALL CONTAIN THE FILE PATHNAME, BUT THEIR FORMAT , describing rm ’s 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)) It is forbidden to remove the names dot and dot-dot in order to avoid the consequences of inadvertently doing something like: rm −r .∗ 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.

HISTORY OF DECISIONS MADE

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 dialogue directly with the user, based on the behavior specified. The −r option is existing practice on all known systems. The synonym −R option is provided for consistency with the other utilities in this standard that provide options requesting recursive descent. 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 unlinkable files should be suppressed. Although this is historical practice, this standard 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. 2 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. POSIX. 2 requires that prompts be done to standard error, for consistency with cp and mv and to allow existing 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, i.e., if the number of file descriptors is limited, rm cannot be implemented in the historical fashion where a 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.