32v 1m chmod
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CHMOD(1) UNIX Programmer's Manual CHMOD(1)
Contents
NAME
chmod - change mode
SYNOPSIS
chmod mode file ...
DESCRIPTION
The mode of each named file is changed according to _m_o_d_e, which may be absolute or symbolic. An absolute _m_o_d_e is an octal number constructed from the OR of the following modes:
4000 set user ID on execution 2000 set group ID on execution 1000 sticky bit, see _c_h_m_o_d(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 _m_o_d_e has the form:
[_w_h_o] _o_p _p_e_r_m_i_s_s_i_o_n [_o_p _p_e_r_m_i_s_s_i_o_n] ...
The _w_h_o part is a combination of the letters u (for user's permissions), g (group) and o (other). The letter a stands for ugo. If _w_h_o is omitted, the default is _a but the setting of the file creation mask (see umask(2)) is taken into account.
_O_p can be + to add _p_e_r_m_i_s_s_i_o_n to the file's mode, - to take away _p_e_r_m_i_s_s_i_o_n and = to assign _p_e_r_m_i_s_s_i_o_n absolutely (all other bits will be reset).
_P_e_r_m_i_s_s_i_o_n is any combination of the letters r (read), w (write), x (execute), s (set owner or group id) and t (save text - sticky). Letters u, g or o indicate that _p_e_r_m_i_s_s_i_o_n is to be taken from the current mode. Omitting _p_e_r_m_i_s_s_i_o_n 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)