xref: /netbsd-src/bin/rm/rm.1 (revision a5847cc334d9a7029f6352b847e9e8d71a0f9e0c)
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33.\"	@(#)rm.1	8.5 (Berkeley) 12/5/94
34.\"
35.Dd August 25, 2006
36.Dt RM 1
37.Os
38.Sh NAME
39.Nm rm
40.Nd remove directory entries
41.Sh SYNOPSIS
42.Nm
43.Op Fl f | Fl i
44.Op Fl dPRrvW
45.Ar
46.Sh DESCRIPTION
47The
48.Nm
49utility attempts to remove the non-directory type files specified on the
50command line.
51If the permissions of the file do not permit writing, and the standard
52input device is a terminal, the user is prompted (on the standard error
53output) for confirmation.
54.Pp
55The options are as follows:
56.Bl -tag -width flag
57.It Fl d
58Attempt to remove directories as well as other types of files.
59.It Fl f
60Attempt to remove the files without prompting for confirmation,
61regardless of the file's permissions.
62If the file does not exist, do not display a diagnostic message or modify
63the exit status to reflect an error.
64The
65.Fl f
66option overrides any previous
67.Fl i
68options.
69.It Fl i
70Request confirmation before attempting to remove each file, regardless of
71the file's permissions, or whether or not the standard input device is a
72terminal.
73The
74.Fl i
75option overrides any previous
76.Fl f
77options.
78.It Fl P
79Overwrite regular files before deleting them.
80Files are overwritten three times, first with the byte pattern 0xff,
81then 0x00, and then with random data, before they are deleted.
82Some care is taken to ensure that the data are actually written to
83disk, but this cannot be guaranteed, even on traditional filesystems;
84on log-structured filesystems or if any block-journaling scheme is
85in use, this option is completely useless.
86If the file cannot be
87overwritten, it will not be removed.
88.It Fl R
89Attempt to remove the file hierarchy rooted in each file argument.
90The
91.Fl R
92option implies the
93.Fl d
94option.
95If the
96.Fl i
97option is specified, the user is prompted for confirmation before
98each directory's contents are processed (as well as before the attempt
99is made to remove the directory).
100If the user does not respond affirmatively, the file hierarchy rooted in
101that directory is skipped.
102.Pp
103.It Fl r
104Equivalent to
105.Fl R .
106.It Fl v
107Cause
108.Nm
109to be verbose, showing files as they are processed.
110.It Fl W
111Attempts to undelete the named files.
112Currently, this option can only be used to recover
113files covered by whiteouts.
114.El
115.Pp
116The
117.Nm
118utility removes symbolic links, not the files referenced by the links.
119.Pp
120It is an error to attempt to remove the files ``.'' and ``..''.
121.Sh EXIT STATUS
122The
123.Nm
124utility exits 0 if all of the named files or file hierarchies were removed,
125or if the
126.Fl f
127option was specified and all of the existing files or file hierarchies were
128removed.
129If an error occurs,
130.Nm
131exits with a value \*[Gt]0.
132.Sh EXAMPLES
133.Nm
134uses
135.Xr getopt 3
136standard argument processing.
137Removing filenames that begin with a dash
138.Pq e.g., Ar -file
139in the current directory which might otherwise be taken as option flags to
140.Nm
141can be accomplished as follows:
142.Pp
143.Ic "rm -- -file"
144.Pp
145or
146.Pp
147.Ic "rm ./-file"
148.Sh SEE ALSO
149.Xr rmdir 1 ,
150.Xr undelete 2 ,
151.Xr unlink 2 ,
152.Xr fts 3 ,
153.Xr getopt 3 ,
154.Xr symlink 7
155.Sh BUGS
156The
157.Fl P
158option assumes that the underlying file system is a fixed-block file
159system.
160FFS is a fixed-block file system, LFS is not.
161In addition, only regular files are overwritten, other types of files
162are not.
163Recent research indicates that as many as 35 overwrite passes with
164carefully chosen data patterns may be necessary to actually prevent
165recovery of data from a magnetic disk.
166Thus the
167.Fl P
168option is likely both insufficient for its design purpose and far
169too costly for default operation.
170However, it will at least prevent the recovery of data from FFS
171volumes with
172.Xr fsdb 8 .
173.Sh COMPATIBILITY
174The
175.Nm
176utility differs from historical implementations in that the
177.Fl f
178option only masks attempts to remove non-existent files instead of
179masking a large variety of errors.
180.Pp
181Also, historical
182.Bx
183implementations prompted on the standard output,
184not the standard error output.
185.Sh STANDARDS
186The
187.Nm
188utility is expected to be
189.St -p1003.2
190compatible.
191The
192.Fl v
193option is an extension.
194.Pp
195The
196.Fl P
197option attempts to conform to U.S. DoD 5220-22.M, "National Industrial
198Security Program Operating Manual" ("NISPOM") as updated by Change
1992 and the July 23, 2003 "Clearing \*[Am] Sanitization Matrix".
200However, unlike earlier revisions of NISPOM, the 2003 matrix imposes
201requirements which make it clear that the standard does not and
202can not apply to the erasure of individual files, in particular
203requirements relating to spare sector management for an entire
204magnetic disk.
205.Em Because these requirements are not met, the
206.Fl P
207.Em option does not conform to the standard .
208