FSF                                                      CHMOD(1)

NAME
     chmod - change file access permissions

SYNOPSIS
     chmod [OPTION]... MODE[,MODE]... FILE...
     chmod [OPTION]... OCTAL-MODE FILE...
     chmod [OPTION]... --reference=RFILE FILE...

DESCRIPTION
     This manual page documents the GNU version of chmod.   chmod
     changes  the  permissions  of  each  given file according to
     mode, which can  be  either  a  symbolic  representation  of
     changes  to  make,  or  an octal number representing the bit
     pattern for the new permissions.

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

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

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

     The letters `rwxXstugo' select the new permissions  for  the
     affected  users: read (r), write (w), execute (or access for
     directories) (x), execute only if the file is a directory or
     already  has  execute permission for some user (X), set user
     or group ID on execution (s), save program text on swap dev-
     ice  (t),  the  permissions  that the user who owns the file
     currently has for it (u), the permissions that  other  users
     in  the  file's  group  have for it (g), and the permissions
     that other users not in the file'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 user ID (4) and set group ID (2) and
     save text image (1) attributes.  The  second  digit  selects
     permissions  for the user who owns the file: read (4), write
     (2), and execute (1);  the  third  selects  permissions  for
     other  users  in the file's group, with the same values; and
     the fourth for other users not in the file's group, with the
     same values.

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FSF                                                      CHMOD(1)

     chmod never changes the permissions of symbolic  links;  the
     chmod  system call cannot change their permissions.  This is
     not a problem since the permissions of  symbolic  links  are
     never  used.   However, for each symbolic link listed on the
     command line, chmod changes the permissions of the  pointed-
     to  file.  In contrast, chmod 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 messages

     -v, --verbose
          output a diagnostic for every file processed

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

     -R, --recursive
          change files and directories recursively

     --help
          display this help and exit

     --version
          output version information and exit

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

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

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FSF                                                      CHMOD(1)

          info chmod

     should give you access to the complete manual.

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