Seth Woolley's Man Viewer

Manual for chmod - man chmod

([section] manual, -k keyword, -K [section] search, -f whatis)
man plain no title

CHMOD(1)                              FSF                             CHMOD(1)



NAME
       chmod(1,2) - change file(1,n) access(2,5) permissions

SYNOPSIS
       chmod(1,2) [OPTION]... MODE[,MODE]... FILE...
       chmod(1,2) [OPTION]... OCTAL-MODE FILE...
       chmod(1,2) [OPTION]... --reference=RFILE FILE...

DESCRIPTION
       This manual page documents the GNU version(1,3,5) of chmod(1,2).  chmod(1,2) changes the
       permissions of each given file(1,n) according to mode, which can be either a
       symbolic  representation  of changes to make, or an octal number repre-
       senting the bit pattern for the new permissions.

       The   format   of   a   symbolic   mode   is    `[ugoa...][[+-=][rwxXs-
       tugo...]...][,...]'.   Multiple symbolic operations can be given, sepa-
       rated by commas.

       A combination of the letters `ugoa' controls which users(1,5)' access(2,5) to the
       file(1,n)  will  be  changed:  the  user who owns it (u), other users(1,5) in(1,8) the
       file(1,n)'s group (g), other users(1,5) not in(1,8) the file(1,n)'s group (o), or all users(1,5)
       (a).   If  none of these are given, the effect is as if(3,n) `a' were given,
       but bits that are set(7,n,1 builtins) in(1,8) the umask are not affected.

       The operator `+' causes the permissions selected to  be  added  to  the
       existing  permissions  of each file(1,n); `-' causes them to be removed; and
       `=' causes them to be the only permissions that the file(1,n) has.

       The letters `rwxXstugo' select(2,7,2 select_tut) the new  permissions  for  the  affected
       users:  read(2,n,1 builtins)  (r),  write(1,2) (w), execute (or access(2,5) for directories) (x),
       execute only if(3,n) the file(1,n) is a directory or already has execute  permis-
       sion  for  some  user  (X), set(7,n,1 builtins) user or group ID on execution (s), save
       program text on swap device (t), the permissions that the user who owns
       the  file(1,n) currently has for it (u), the permissions that other users(1,5) in(1,8)
       the file(1,n)'s group have for it (g), and the permissions that other  users(1,5)
       not in(1,8) the file(1,n)'s group have for it (o).

       A  numeric  mode  is  from  one  to four octal digits (0-7), derived by
       adding up the bits with values 4, 2, and 1.   Any  omitted  digits  are
       assumed  to  be leading zeros.  The first digit selects the set(7,n,1 builtins) user ID
       (4) and set(7,n,1 builtins) group ID (2) and save text image (1) attributes.  The  sec-
       ond digit selects permissions for the user who owns the file: read(2,n,1 builtins) (4),
       write(1,2) (2), and execute (1); the third  selects  permissions  for  other
       users(1,5)  in(1,8)  the  file(1,n)'s  group, with the same values; and the fourth for
       other users(1,5) not in(1,8) the file(1,n)'s group, with the same values.

       chmod(1,2) never changes the permissions of symbolic links; the chmod(1,2) system
       call  cannot change their permissions.  This is not a problem since the
       permissions of symbolic links are never used.  However, for  each  sym-
       bolic link(1,2) listed on the command line, chmod(1,2) changes the permissions of
       the pointed-to file.  In contrast, chmod(1,2) ignores symbolic links encoun-
       tered during recursive directory traversals.

OPTIONS
       Change the mode of each FILE to MODE.

       -c, --changes
              like verbose but report only when a change is made

       -f, --silent, --quiet
              suppress most error(8,n) messages

       -v, --verbose
              output a diagnostic for every file(1,n) processed

       --reference=RFILE
              use RFILE's mode instead of MODE values

       -R, --recursive
              change files and directories recursively

       --help display this help and exit(3,n,1 builtins)

       --version
              output version(1,3,5) information and exit(3,n,1 builtins)

       Each  MODE  is  one or more of the letters ugoa, one of the symbols +-=
       and one or more of the letters rwxXstugo.

AUTHOR
       Written by David MacKenzie.

REPORTING BUGS
       Report bugs to <bug-fileutils@gnu.org>.

COPYRIGHT
       Copyright  2001 Free Software Foundation, Inc.
       This is free software; see the source for copying conditions.  There is
       NO  warranty;  not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
       PURPOSE.

SEE ALSO
       The full documentation for chmod(1,2) is maintained as a Texinfo manual.  If
       the  info(1,5,n)  and  chmod(1,2) programs are properly installed at your site, the
       command

              info(1,5,n) chmod(1,2)

       should give you access(2,5) to the complete manual.



chmod(1,2) (fileutils) 4.1             April 2001                          CHMOD(1)

References for this manual (incoming links)