1.\" $NetBSD: chmod.1,v 1.17 2002/02/08 01:21:55 ross Exp $ 2.\" 3.\" Copyright (c) 1989, 1990, 1993, 1994 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. All advertising materials mentioning features or use of this software 18.\" must display the following acknowledgement: 19.\" This product includes software developed by the University of 20.\" California, Berkeley and its contributors. 21.\" 4. Neither the name of the University nor the names of its contributors 22.\" may be used to endorse or promote products derived from this software 23.\" without specific prior written permission. 24.\" 25.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35.\" SUCH DAMAGE. 36.\" 37.\" @(#)chmod.1 8.4 (Berkeley) 3/31/94 38.\" 39.Dd October 11, 2000 40.Dt CHMOD 1 41.Os 42.Sh NAME 43.Nm chmod 44.Nd change file modes 45.Sh SYNOPSIS 46.Nm 47.Oo 48.Fl R 49.Op Fl H | Fl L | Fl P 50.Oc 51.Op Fl h 52.Ar mode 53.Ar 54.Sh DESCRIPTION 55The 56.Nm 57utility modifies the file mode bits of the listed files 58as specified by the 59.Ar mode 60operand. 61.Pp 62The options are as follows: 63.Bl -tag -width Ds 64.It Fl H 65If the 66.Fl R 67option is specified, symbolic links on the command line are followed. 68(Symbolic links encountered in the tree traversal are not followed.) 69.It Fl L 70If the 71.Fl R 72option is specified, all symbolic links are followed. 73.It Fl P 74If the 75.Fl R 76option is specified, no symbolic links are followed. 77.It Fl R 78Change the modes of the file hierarchies rooted in the files 79instead of just the files themselves. 80.It Fl h 81If 82.Ar file 83is symbolic link, the mode of the link is changed. 84.El 85.Pp 86If the option 87.Fl h 88is not given, unless the 89.Fl H 90or 91.Fl L 92option is set, 93.Nm 94on a symbolic link always succeeds and has no effect. 95The 96.Fl H , 97.Fl L 98and 99.Fl P 100options are ignored unless the 101.Fl R 102option is specified. 103In addition, these options override each other and the 104command's actions are determined by the last one specified. 105.Pp 106Only the owner of a file or the super-user is permitted to change 107the mode of a file. 108.Sh EXIT STATUS 109The 110.Nm 111utility exits 0 on success, and \*[Gt]0 if an error occurs. 112.Sh MODES 113Modes may be absolute or symbolic. 114An absolute mode is an octal number constructed by 115.Em or Ap ing 116the following values: 117.Pp 118.Bl -tag -width 6n -compact -offset indent 119.It Li 4000 120set-user-ID-on-execution 121.It Li 2000 122set-group-ID-on-execution 123.It Li 1000 124sticky bit, see 125.Xr chmod 2 126.It Li 0400 127read by owner 128.It Li 0200 129write by owner 130.It Li 0100 131execute (or search for directories) by owner 132.It Li 0070 133read, write, execute/search by group 134.It Li 0007 135read, write, execute/search by others 136.El 137.Pp 138The read, write, and execute/search values for group and others 139are encoded as described for owner. 140.Pp 141The symbolic mode is described by the following grammar: 142.Bd -literal -offset indent 143mode ::= clause [, clause ...] 144clause ::= [who ...] [action ...] last_action 145action ::= op [perm ...] 146last_action ::= op [perm ...] 147who ::= a | u | g | o 148op ::= + | \- | = 149perm ::= r | s | t | w | x | X | u | g | o 150.Ed 151.Pp 152The 153.Ar who 154symbols ``u'', ``g'', and ``o'' specify the user, group, and other parts 155of the mode bits, respectively. 156The 157.Ar who 158symbol ``a'' is equivalent to ``ugo''. 159.Pp 160.ne 1i 161The 162.Ar perm 163symbols represent the portions of the mode bits as follows: 164.Pp 165.Bl -tag -width Ds -compact -offset indent 166.It r 167The read bits. 168.It s 169The set-user-ID-on-execution and set-group-ID-on-execution bits. 170.It t 171The sticky bit. 172.It w 173The write bits. 174.It x 175The execute/search bits. 176.It X 177The execute/search bits if the file is a directory or any of the 178execute/search bits are set in the original (unmodified) mode. 179Operations with the 180.Ar perm 181symbol ``X'' are only meaningful in conjunction with the 182.Ar op 183symbol ``+'', and are ignored in all other cases. 184.It u 185The user permission bits in the mode of the original file. 186.It g 187The group permission bits in the mode of the original file. 188.It o 189The other permission bits in the mode of the original file. 190.El 191.Pp 192The 193.Ar op 194symbols represent the operation performed, as follows: 195.Bl -tag -width 4n 196.It + 197If no value is supplied for 198.Ar perm , 199the ``+'' operation has no effect. 200If no value is supplied for 201.Ar who , 202each permission bit specified in 203.Ar perm , 204for which the corresponding bit in the file mode creation mask 205is clear, is set. 206Otherwise, the mode bits represented by the specified 207.Ar who 208and 209.Ar perm 210values are set. 211.It \&\- 212If no value is supplied for 213.Ar perm , 214the ``\-'' operation has no effect. 215If no value is supplied for 216.Ar who , 217each permission bit specified in 218.Ar perm , 219for which the corresponding bit in the file mode creation mask 220is clear, is cleared. 221Otherwise, the mode bits represented by the specified 222.Ar who 223and 224.Ar perm 225values are cleared. 226.It = 227The mode bits specified by the 228.Ar who 229value are cleared, or, if no who value is specified, the owner, group 230and other mode bits are cleared. 231Then, if no value is supplied for 232.Ar who , 233each permission bit specified in 234.Ar perm , 235for which the corresponding bit in the file mode creation mask 236is clear, is set. 237Otherwise, the mode bits represented by the specified 238.Ar who 239and 240.Ar perm 241values are set. 242.El 243.Pp 244Each 245.Ar clause 246specifies one or more operations to be performed on the mode 247bits, and each operation is applied to the mode bits in the 248order specified. 249.Pp 250Operations upon the other permissions only (specified by the symbol 251``o'' by itself), in combination with the 252.Ar perm 253symbols ``s'' or ``t'', are ignored. 254.Sh EXAMPLES 255.Bl -tag -width "u=rwx,go=u-w" -compact 256.It Li 644 257make a file readable by anyone and writable by the owner only. 258.Pp 259.It Li go-w 260deny write permission to group and others. 261.Pp 262.It Li =rw,+X 263set the read and write permissions to the usual defaults, but 264retain any execute permissions that are currently set. 265.Pp 266.It Li +X 267make a directory or file searchable/executable by everyone if it is 268already searchable/executable by anyone. 269.Pp 270.It Li 755 271.It Li u=rwx,go=rx 272.It Li u=rwx,go=u-w 273make a file readable/executable by everyone and writable by the owner only. 274.Pp 275.It Li go= 276clear all mode bits for group and others. 277.Pp 278.It Li g=u-w 279set the group bits equal to the user bits, but clear the group write bit. 280.El 281.Sh SEE ALSO 282.Xr install 1 , 283.Xr chmod 2 , 284.Xr stat 2 , 285.Xr umask 2 , 286.Xr fts 3 , 287.Xr setmode 3 , 288.Xr symlink 7 , 289.Xr chown 8 290.Sh STANDARDS 291The 292.Nm 293utility is expected to be 294.St -p1003.2-92 295compatible with the exception of the 296.Ar perm 297symbol 298.Dq t 299which is not included in that standard. 300.Sh BUGS 301There's no 302.Ar perm 303option for the naughty bits. 304