1.\" $NetBSD: rm.1,v 1.27 2013/04/26 19:34:34 wiz Exp $ 2.\" 3.\" Copyright (c) 1990, 1993, 1994, 2003 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" the Institute of Electrical and Electronics Engineers, Inc. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. Neither the name of the University nor the names of its contributors 18.\" may be used to endorse or promote products derived from this software 19.\" without specific prior written permission. 20.\" 21.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31.\" SUCH DAMAGE. 32.\" 33.\" @(#)rm.1 8.5 (Berkeley) 12/5/94 34.\" 35.Dd April 26, 2013 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 dPRrvWx 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.It Fl r 103Equivalent to 104.Fl R . 105.It Fl v 106Cause 107.Nm 108to be verbose, showing files as they are processed. 109.It Fl W 110Attempts to undelete the named files. 111Currently, this option can only be used to recover 112files covered by whiteouts. 113.It Fl x 114When removing a hierarchy, do not cross mount points. 115.El 116.Pp 117The 118.Nm 119utility removes symbolic links, not the files referenced by the links. 120.Pp 121It is an error to attempt to remove the files ``.'' and ``..''. 122.Sh EXIT STATUS 123The 124.Nm 125utility exits 0 if all of the named files or file hierarchies were removed, 126or if the 127.Fl f 128option was specified and all of the existing files or file hierarchies were 129removed. 130If an error occurs, 131.Nm 132exits with a value \*[Gt]0. 133.Sh EXAMPLES 134.Nm 135uses 136.Xr getopt 3 137standard argument processing. 138Removing filenames that begin with a dash 139.Pq e.g., Ar -file 140in the current directory which might otherwise be taken as option flags to 141.Nm 142can be accomplished as follows: 143.Pp 144.Ic "rm -- -file" 145.Pp 146or 147.Pp 148.Ic "rm ./-file" 149.Sh COMPATIBILITY 150The 151.Nm 152utility differs from historical implementations in that the 153.Fl f 154option only masks attempts to remove non-existent files instead of 155masking a large variety of errors. 156.Pp 157Also, historical 158.Bx 159implementations prompted on the standard output, 160not the standard error output. 161.Sh SEE ALSO 162.Xr rmdir 1 , 163.Xr undelete 2 , 164.Xr unlink 2 , 165.Xr fts 3 , 166.Xr getopt 3 , 167.Xr symlink 7 168.Sh STANDARDS 169The 170.Nm 171utility is expected to be 172.St -p1003.2 173compatible. 174The 175.Fl v 176and 177.Fl x 178options are extensions. 179.Pp 180The 181.Fl P 182option attempts to conform to U.S. DoD 5220-22.M, "National Industrial 183Security Program Operating Manual" ("NISPOM") as updated by Change 1842 and the July 23, 2003 "Clearing \*[Am] Sanitization Matrix". 185However, unlike earlier revisions of NISPOM, the 2003 matrix imposes 186requirements which make it clear that the standard does not and 187can not apply to the erasure of individual files, in particular 188requirements relating to spare sector management for an entire 189magnetic disk. 190.Em Because these requirements are not met, the 191.Fl P 192.Em option does not conform to the standard . 193.Sh BUGS 194The 195.Fl P 196option assumes that the underlying file system is a fixed-block file 197system. 198FFS is a fixed-block file system, LFS is not. 199In addition, only regular files are overwritten, other types of files 200are not. 201Recent research indicates that as many as 35 overwrite passes with 202carefully chosen data patterns may be necessary to actually prevent 203recovery of data from a magnetic disk. 204Thus the 205.Fl P 206option is likely both insufficient for its design purpose and far 207too costly for default operation. 208However, it will at least prevent the recovery of data from FFS 209volumes with 210.Xr fsdb 8 . 211