1.\" Copyright (c) 1989, 1990 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" the Institute of Electrical and Electronics Engineers, Inc. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. All advertising materials mentioning features or use of this software 16.\" must display the following acknowledgement: 17.\" This product includes software developed by the University of 18.\" California, Berkeley and its contributors. 19.\" 4. Neither the name of the University nor the names of its contributors 20.\" may be used to endorse or promote products derived from this software 21.\" without specific prior written permission. 22.\" 23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33.\" SUCH DAMAGE. 34.\" 35.\" @(#)chmod.1 6.15 (Berkeley) 7/23/91 36.\" 37.Dd July 23, 1991 38.Dt CHMOD 1 39.Os 40.Sh NAME 41.Nm chmod 42.Nd change file modes 43.Sh SYNOPSIS 44.Nm chmod 45.Op Fl R 46.Ar mode 47.Ar file ... 48.Sh DESCRIPTION 49The 50.Nm chmod 51utility modifies the file mode bits of the listed files 52as specified by the 53.Ar mode 54operand. 55.Pp 56The options are as follows: 57.Bl -tag -width Ds 58.It Fl R 59Traverse a file hierarchy. 60For each file that is of type directory, 61.Nm chmod 62changes the mode of all files in the file hierarchy below it followed 63by the mode of the directory itself. 64.El 65.Pp 66Symbolic links are not indirected through, nor are their modes altered. 67.Pp 68Only the owner of a file or the super-user is permitted to change 69the mode of a file. 70.Pp 71The 72.Nm chmod 73utility exits 0 on success, and >0 if an error occurs. 74.Sh MODES 75Modes may be absolute or symbolic. 76An absolute mode is an octal number constructed by 77.Ar or Ap ing 78the following values: 79.Pp 80.Bl -tag -width 6n -compact -offset indent 81.It Li 4000 82set-user-ID-on-execution 83.It Li 2000 84set-group-ID-on-execution 85.It Li 1000 86sticky bit, see chmod(2) 87.It Li 0400 88read by owner 89.It Li 0200 90write by owner 91.It Li 0100 92execute (or search for directories) by owner 93.It Li 0070 94read, write, execute/search by group 95.It Li 0007 96read, write, execute/search by others 97.El 98.Pp 99The read, write, and execute/search values for group and others 100are encoded as described for owner. 101.Pp 102The symbolic mode is described by the following grammar: 103.Bd -literal -offset indent 104mode ::= clause [, clause ...] 105clause ::= [who ...] [action ...] last_action 106action ::= op [perm ...] 107last_action ::= op [perm ...] 108who ::= a | u | g | o 109op ::= + | \- | = 110perm ::= r | s | t | w | X | x | u | g | o 111.Ed 112.Pp 113The 114.Ar who 115symbols ``u'', ``g'', and ``o'' specify the user, group, and other parts 116of the mode bits, respectively. 117The 118.Ar who 119symbol ``a'' is equivalent to ``ugo''. 120.Pp 121The 122.Ar perm 123symbols represent the portions of the mode bits as follows: 124.Pp 125.Bl -tag -width Ds -compact -offset indent 126.It r 127The read bits. 128.It s 129The set-user-ID-on-execution and set-group-ID-on-execution bits. 130.It t 131The sticky bit. 132.It w 133The write bits. 134.It x 135The execute/search bits. 136.It X 137The execute/search bits if the file is a directory or any of the 138execute/search bits are set in the original (unmodified) mode. 139Operations with the 140.Ar perm 141symbol ``X'' are only meaningful in conjunction with the 142.Ar op 143symbol ``+'', and it is ignored in all other cases. 144.El 145.Pp 146The 147.Ar op 148symbols represent the operation performed, as follows: 149.Bl -tag -width 4n 150.It + 151If no value is supplied for 152.Ar perm , 153the ``+'' operation has no effect. 154If no value is supplied for 155.Ar who , 156each permission bit specified in 157.Ar perm , 158for which the corresponding bit in the file mode creation mask 159is clear, is set. 160Otherwise, the mode bits represented by the specified 161.Ar who 162and 163.Ar perm 164values are set. 165.It \&\- 166If no value is supplied for 167.Ar perm , 168the ``\-'' operation has no effect. 169If no value is supplied for 170.Ar who , 171the mode bits represented by 172.Ar perm 173are cleared for the owner, group and other permissions. 174Otherwise, the mode bits represented by the specified 175.Ar who 176and 177.Ar perm 178values are cleared. 179.It = 180The mode bits specified by the 181.Ar who 182value are cleared, or, if no who value is specified, the owner, group 183and other mode bits are cleared. 184Then, if no value is supplied for 185.Ar who , 186each permission bit specified in 187.Ar perm , 188for which the corresponding bit in the file mode creation mask 189is clear, is set. 190Otherwise, the mode bits represented by the specified 191.Ar who 192and 193.Ar perm 194values are set. 195.El 196.Pp 197Each 198.Ar clause 199specifies one or more operations to be performed on the mode 200bits, and each operation is applied to the mode bits in the 201order specified. 202.Pp 203Operations upon the other permissions only (specified by the symbol 204``o'' by itself), in combination with the 205.Ar perm 206symbols ``s'' or ``t'', are ignored. 207.Sh EXAMPLES 208.Bl -tag -width "u=rwx,go=u-w" -compact 209.It Li 644 210make a file readable by anyone and writable by the owner only. 211.Pp 212.It Li go-w 213deny write permission to group and others. 214.Pp 215.It Li =rw,+X 216set the read and write permissions to the usual defaults, but 217retain any execute permissions that are currently set. 218.Pp 219.It Li +X 220make a directory or file searchable/executable by everyone if it is 221already searchable/executable by anyone. 222.Pp 223.It Li 755 224.It Li u=rwx,go=rx 225.It Li u=rwx,go=u-w 226make a file readable/executable by everyone and writeable by the owner only. 227.Pp 228.It Li go= 229clear all mode bits for group and others. 230.Pp 231.It Li g=u-w 232set the group bits equal to the user bits, but clear the group write bit. 233.El 234.Sh BUGS 235There's no 236.Ar perm 237option for the naughty bits. 238.Sh SEE ALSO 239.Xr install 1 , 240.Xr chmod 2 , 241.Xr stat 2 , 242.Xr umask 2 , 243.Xr fts 3 , 244.Xr setmode 3 , 245.Xr chown 8 246.Sh STANDARDS 247The 248.Nm chmod 249utility is expected to be 250.St -p1003.2 251compatible with the exception 252of the 253.Ar perm 254symbols 255.Dq t 256and 257.Dq X 258which are not included in that standard. 259