NAME

chmod − change mode

SYNOPSIS

chmod octal file ... 

DESCRIPTION

The octal mode replaces the mode of each of the files.  The mode is constructed from the OR of the following modes:

4000set user ID on execution

2000set group ID on execution

1000sticky bit for shared, pure-procedure programs (see below)

0400read by owner

0200write by owner

0100execute (search in directory) by owner

0070read, write, execute (search) by group

0007read, write, execute (search) by others

Only the owner of a file (or the super-user) may change its mode.  If an executable file is set up for sharing (“−n” option of "ld (I)" ), 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. 

SEE ALSO

ls (I), chmod (II)

BUGS