chmod – change mode|
chmod mode file ...|
The mode of each named file is changed according to mode, which
may be an octal number or a symbolic change to the existing mode.
A mode is an octal number constructed from the OR of the following
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:
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), a (append only), l (exclusive access), and t (temporary file).
Only the owner of a file or the group leader of its group may
change the file's mode.
ls(1), stat(2), stat(5)|