# chmod(1)

    NAME
         chmod - change access mode for files

    SYNOPSIS
         chmod [-R] mode file ...

    OPTIONS

         -R   Change hierarchies recursively

    EXAMPLES

         chmod 755 file      # Owner: rwx Group: r-x Others: r-x

         chmod +x file1 file2
                             # Make file1 and file2 executable

         chmod a-w file      # Make file read only

         chmod u+s file      # Turn on SETUID for file

         chmod -R o+w dir    # Allow writing for all files in dir

    DESCRIPTION

         The given mode is applied to each file in the file list. If the  -R  flag
         is  present,  the files in a directory will be changed as well.  The mode
         can be either absolute or symbolic. Absolute modes are given as an  octal
         number  that  represents  the new file mode. The mode bits are defined as
         follows:

            4000    Set effective user id on execution to file's owner id
            2000    Set effective group id on execution to file's group id
            0400    file is readable by the owner of the file
            0200    writeable by owner
            0100    executable by owner
            0070    same as above, for other users in the same group
            0007    same as above, for all other users

         Symbolic modes modify the current file mode in a specified way. The  form
         is:

            [who] op permissions { op permissions ...} {, [who] op ... }

         The possibilities for who are u, g, o, and a, standing for  user,  group,
         other  and  all,  respectively.  If who is omitted, a is assumed, but the
         current umask is used. The op can be +, -, or =;  + turns  on  the  given
         permissions, - turns them off; = sets the permissions exclusively for the
         given who. For example g=x sets the group permissions to --x.

         The possible permissions are r, w, x; which stand for  read,  write,  and
         execute;   s  turns on the set effective user/group id bits. s only makes
         sense with u and g; o+s is harmless.

    SEE ALSO
         ls(1), chmod(2).