chmod(2) [v7 man page]

CHMOD(2)							System Calls Manual							  CHMOD(2)

NAME

       chmod - change mode of file

SYNOPSIS

       chmod(name, mode)
       char *name;

DESCRIPTION

       The file whose name is given as the null-terminated string pointed to by name has its mode changed to mode.  Modes are constructed by ORing
       together some combination of the following:

	       04000 set user ID on execution
	       02000 set group ID on execution
	       01000 save text image after execution
	       00400 read by owner
	       00200 write by owner
	       00100 execute (search on directory) by owner
	       00070 read, write, execute (search) by group
	       00007 read, write, execute (search) by others

       If an executable file is set up for sharing (-n or -i option of ld(1)) then mode 1000 prevents the system from  abandoning  the	swap-space
       image  of  the  program-text  portion of the file when its last user terminates.  Thus when the next user of the file executes it, the text
       need not be read from the file system but can simply be swapped in, saving time.  Ability to set this bit is restricted to  the	super-user
       since swap space is consumed by the images; it is only worth while for heavily used commands.

       Only the owner of a file (or the super-user) may change the mode.  Only the super-user can set the 1000 mode.

SEE ALSO

       chmod(1)

DIAGNOSTIC

       Zero is returned if the mode is changed; -1 is returned if name cannot be found or if current user is neither the owner of the file nor the
       super-user.

ASSEMBLER

       (chmod = 15.)
       sys chmod; name; mode

																	  CHMOD(2)

CHMOD(1)						      General Commands Manual							  CHMOD(1)

NAME

       chmod - change mode

SYNOPSIS

       chmod mode file ...

DESCRIPTION

       The  mode  of  each  named  file is changed according to mode, which may be absolute or symbolic.  An absolute mode is an octal number con-
       structed from the OR of the following modes:

       4000	 set user ID on execution
       2000	 set group ID on execution
       1000	 sticky bit, see chmod(2)
       0400	 read by owner
       0200	 write by owner
       0100	 execute (search in directory) by owner
       0070	 read, write, execute (search) by group
       0007	 read, write, execute (search) by others

       A symbolic mode has the form:

	      [who] op permission [op permission] ...

       The who part is a combination of the letters u (for user's permissions), g (group) and o (other).  The letter a stands for ugo.	If who	is
       omitted, the default is a but the setting of the file creation mask (see umask(2)) is taken into account.

       Op  can	be + to add permission to the file's mode, - to take away permission and = to assign permission absolutely (all other bits will be
       reset).

       Permission is any combination of the letters r (read), w (write), x (execute), s (set owner or group id) and t (save text - sticky).   Let-
       ters  u,  g or o indicate that permission is to be taken from the current mode.	Omitting permission is only useful with = to take away all
       permissions.

       The first example denies write permission to others, the second makes a file executable:

	      chmod o-w file
	      chmod +x file

       Multiple symbolic modes separated by commas may be given.  Operations are performed in the order specified.  The letter s  is  only  useful
       with u or g.

       Only the owner of a file (or the super-user) may change its mode.

SEE ALSO

       ls(1), chmod(2), chown (1), stat(2), umask(2)

																	  CHMOD(1)