freebsd/bin/rm/rm.1

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.\"	@(#)rm.1	8.5 (Berkeley) 12/5/94
.\" $FreeBSD$
.\"
.Dd October 31, 2010
.Dt RM 1
.Os
.Sh NAME
.Nm rm ,
.Nm unlink
.Nd remove directory entries
.Sh SYNOPSIS
.Nm
.Op Fl f | i
.Op Fl dIPRrvW
.Ar
.Nm unlink
.Ar file
.Sh DESCRIPTION
The
.Nm
utility attempts to remove the non-directory type files specified on the
command line.
If the permissions of the file do not permit writing, and the standard
input device is a terminal, the user is prompted (on the standard error
output) for confirmation.
.Pp
The options are as follows:
.Bl -tag -width indent
.It Fl d
Attempt to remove directories as well as other types of files.
.It Fl f
Attempt to remove the files without prompting for confirmation,
regardless of the file's permissions.
If the file does not exist, do not display a diagnostic message or modify
the exit status to reflect an error.
The
.Fl f
option overrides any previous
.Fl i
options.
.It Fl i
Request confirmation before attempting to remove each file, regardless of
the file's permissions, or whether or not the standard input device is a
terminal.
The
.Fl i
option overrides any previous
.Fl f
options.
.It Fl I
Request confirmation once if more than three files are being removed or if a
directory is being recursively removed.
This is a far less intrusive option than
.Fl i
yet provides almost the same level of protection against mistakes.
.It Fl P
Overwrite regular files before deleting them.
Files are overwritten three times, first with the byte pattern 0xff,
then 0x00, and then 0xff again, before they are deleted.
Files with multiple links will not be overwritten nor deleted
and a warning will be issued.
If the
.Fl f
option is specified, files with multiple links will also be overwritten
and deleted.
No warning will be issued.
.Pp
Specifying this flag for a read only file will cause
.Nm
to generate an error message and exit.
The file will not be removed or overwritten.
.Pp
N.B.: The
.Fl P
flag is not considered a security feature
.Pq see Sx BUGS .
.It Fl R
Attempt to remove the file hierarchy rooted in each
.Ar file
argument.
The
.Fl R
option implies the
.Fl d
option.
If the
.Fl i
option is specified, the user is prompted for confirmation before
each directory's contents are processed (as well as before the attempt
is made to remove the directory).
If the user does not respond affirmatively, the file hierarchy rooted in
that directory is skipped.
.Pp
.It Fl r
Equivalent to
.Fl R .
.It Fl v
Be verbose when deleting files, showing them as they are removed.
.It Fl W
Attempt to undelete the named files.
Currently, this option can only be used to recover
files covered by whiteouts in a union file system (see
.Xr undelete 2 ) .
.El
.Pp
The
.Nm
utility removes symbolic links, not the files referenced by the links.
.Pp
It is an error to attempt to remove the files
.Pa / ,
.Pa .\&
or
.Pa .. .
.Pp
When the utility is called as
.Nm unlink ,
only one argument,
which must not be a directory,
may be supplied.
No options may be supplied in this simple mode of operation,
which performs an
.Xr unlink 2
operation on the passed argument.
.Sh EXIT STATUS
The
.Nm
utility exits 0 if all of the named files or file hierarchies were removed,
or if the
.Fl f
option was specified and all of the existing files or file hierarchies were
removed.
If an error occurs,
.Nm
exits with a value >0.
.Sh NOTES
The
.Nm
command uses
.Xr getopt 3
to parse its arguments, which allows it to accept
the
.Sq Li --
option which will cause it to stop processing flag options at that
point.
This will allow the removal of file names that begin
with a dash
.Pq Sq - .
For example:
.Pp
.Dl "rm -- -filename"
.Pp
The same behavior can be obtained by using an absolute or relative
path reference.
For example:
.Pp
.Dl "rm /home/user/-filename"
.Dl "rm ./-filename"
.Pp
When
.Fl P
is specified with
.Fl f
the file will be overwritten and removed even if it has hard links.
.Sh COMPATIBILITY
The
.Nm
utility differs from historical implementations in that the
.Fl f
option only masks attempts to remove non-existent files instead of
masking a large variety of errors.
The
.Fl v
option is non-standard and its use in scripts is not recommended.
.Pp
Also, historical
.Bx
implementations prompted on the standard output,
not the standard error output.
.Sh SEE ALSO
.Xr chflags 1 ,
.Xr rmdir 1 ,
.Xr undelete 2 ,
.Xr unlink 2 ,
.Xr fts 3 ,
.Xr getopt 3 ,
.Xr symlink 7
.Sh STANDARDS
The
.Nm
command conforms to
.St -p1003.2 .
.Pp
The simplified
.Nm unlink
command conforms to
.St -susv2 .
.Sh HISTORY
A
.Nm
command appeared in
.At v1 .
.Sh BUGS
The
.Fl P
option assumes that the underlying storage overwrites file blocks
when data is written to an existing offset.
Several factors including the file system and its backing store could defeat
this assumption.
This includes, but is not limited to file systems that use a
Copy-On-Write strategy (e.g. ZFS or UFS when snapshots are being used), Flash
media that are using a wear leveling algorithm, or when the backing datastore
does journaling, etc.
In addition, only regular files are overwritten, other types of files are not.