CHMOD(1) General Commands Manual CHMOD(1)

chmod - change file mode (permissions)

chmod mode file ...

Chmod changes the mode (permissions) of each file according to mode, which may be an octal number or a symbolic change to the existing mode.

A mode can be numerically formed as the OR of the following octal values (a leading 8r is ignored):

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

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.

The op field can be: + to add permission to the file's mode, - to take away permission, = to assign permission absolutely (all other bits being reset).

The permission field is any combination of the letters r (read), w (write), x (execute), a (append only), l (exclusive access), and t (temporary, not archived).

/appl/cmd/chmod.b

chgrp (1), ls (1), sys-stat (2)

The interpretation of the modes is limited on some host operating systems, particularly variants of Windows.