Copyright (c) 1980 Regents of the University of California.
All rights reserved. The Berkeley software License Agreement
specifies the terms and conditions for redistribution.

@(#)chmod.2 4.1 (Berkeley) 05/09/85

C 4 chmod - change mode of file

 chmod(name, mode)  char *name; 

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 or ing together some combination of the following:

If an executable file is set up for sharing (this is the default) 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. Ability to set this bit is restricted to the super-user since swap space is consumed by the images. See sticky (8).

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

On some systems, writing or changing the owner of a file turns off the set-user-id bit. This makes the system somewhat more secure by protecting set-user-id files from remaining set-user-id if they are modified, at the expense of a degree of compatibility.

chmod(1) Zero is returned if the mode is changed; -1 is returned if name cannot be found or if the current user is neither the owner of the file nor the super-user. (chmod = 15.)

sys chmod; name; mode