[unix-history] / usr / man / man1 / chmod.1

.TH CHMOD 1 
.SH NAME
chmod \- change mode
.SH SYNOPSIS
.B chmod
mode file ...
.SH DESCRIPTION
The mode of
each named file
is changed
according to
.I mode,
which may be absolute or symbolic.
An absolute
.I mode
is an octal
number constructed
from the OR of the
following modes:
.TP 10
4000
set user ID on execution
.br
.br
.ns
.TP 10
2000
set group ID on execution
.br
.br
.ns
.TP 10
1000
sticky bit, see
.IR  chmod (2)
.br
.br
.ns
.TP 10
0400
read by owner
.br
.br
.ns
.TP 10
0200
write by owner
.br
.br
.ns
.TP 10
0100
execute (search in directory) by owner
.br
.br
.ns
.TP 10
0070
read, write, execute (search) by group
.br
.br
.ns
.TP 10
0007
read, write, execute (search) by others
.PP
A symbolic
.I mode
has the form:
.IP
.RI [ who ]
.I op permission
.RI [ "op permission" "] ..."
.PP
The
.I who
part is a combination
of the letters 
.B u
(for user's permissions),
.B g
(group)
and
.B o
(other).
The letter
.B a
stands for
.B ugo.
If
.I who
is omitted,
the default is
.I a
but the setting of
the file creation mask
(see umask(2))
is taken into account.
.PP
.I Op
can be
.B +
to add
.I permission
to the file's mode,
.B \-
to take away
.I permission
and
.B =
to assign
.I permission
absolutely
(all other bits will
be reset).
.PP
.I Permission
is any combination of the letters
.B r
(read),
.B w
(write),
.B x
(execute),
.B s
(set owner or group id)
and
.B t
(save text \- sticky).
Letters
.BR u,
.B g
or
.B o
indicate that
.I permission
is to be taken
from the current
mode.
Omitting
.I permission
is only useful
with
.B =
to take away
all permissions.
.PP
The first example denies write permission to others,
the second makes a file executable:
.IP
chmod o\-w file
.br
chmod +x file
.PP
Multiple symbolic modes separated by commas may be given.
Operations are performed
in the order specified.
The letter
.B s
is only useful
with
.B u
or
.B g.
.PP
Only the owner of a file (or the super-user) may change its mode.
.SH "SEE ALSO"
ls(1),
chmod(2),
chown (1),
stat(2),
umask(2)
Commit	Line	Data
c1db0f95 KT	1	.TH CHMOD 1
	2	.SH NAME
	3	chmod \- change mode
	4	.SH SYNOPSIS
	5	.B chmod
	6	mode file ...
	7	.SH DESCRIPTION
	8	The mode of
	9	each named file
	10	is changed
	11	according to
	12	.I mode,
	13	which may be absolute or symbolic.
	14	An absolute
	15	.I mode
	16	is an octal
	17	number constructed
	18	from the OR of the
	19	following modes:
	20	.TP 10
	21	4000
	22	set user ID on execution
	23	.br
	24	.br
	25	.ns
	26	.TP 10
	27	2000
	28	set group ID on execution
	29	.br
	30	.br
	31	.ns
	32	.TP 10
	33	1000
	34	sticky bit, see
	35	.IR chmod (2)
	36	.br
	37	.br
	38	.ns
	39	.TP 10
	40	0400
	41	read by owner
	42	.br
	43	.br
	44	.ns
	45	.TP 10
	46	0200
	47	write by owner
	48	.br
	49	.br
	50	.ns
	51	.TP 10
	52	0100
	53	execute (search in directory) by owner
	54	.br
	55	.br
	56	.ns
	57	.TP 10
	58	0070
	59	read, write, execute (search) by group
	60	.br
	61	.br
	62	.ns
	63	.TP 10
	64	0007
65	read, write, execute (search) by others
66	.PP
67	A symbolic
68	.I mode
69	has the form:
70	.IP
71	.RI [ who ]
72	.I op permission
73	.RI [ "op permission" "] ..."
74	.PP
75	The
76	.I who
77	part is a combination
78	of the letters
79	.B u
80	(for user's permissions),
81	.B g
82	(group)
83	and
84	.B o
85	(other).
86	The letter
87	.B a
88	stands for
89	.B ugo.
90	If
91	.I who
92	is omitted,
93	the default is
94	.I a
95	but the setting of
96	the file creation mask
97	(see umask(2))
98	is taken into account.
99	.PP
100	.I Op
101	can be
102	.B +
103	to add
104	.I permission
105	to the file's mode,
106	.B \-
107	to take away
108	.I permission
109	and
110	.B =
111	to assign
112	.I permission
113	absolutely
114	(all other bits will
115	be reset).
116	.PP
117	.I Permission
118	is any combination of the letters
119	.B r
120	(read),
121	.B w
122	(write),
123	.B x
124	(execute),
125	.B s
126	(set owner or group id)
127	and
128	.B t
129	(save text \- sticky).
130	Letters
131	.BR u,
132	.B g
133	or
134	.B o
135	indicate that
136	.I permission
137	is to be taken
138	from the current
139	mode.
140	Omitting
141	.I permission
142	is only useful
143	with
144	.B =
145	to take away
146	all permissions.
147	.PP
148	The first example denies write permission to others,
149	the second makes a file executable:
150	.IP
151	chmod o\-w file
152	.br
153	chmod +x file
154	.PP
155	Multiple symbolic modes separated by commas may be given.
156	Operations are performed
157	in the order specified.
158	The letter
159	.B s
160	is only useful
161	with
162	.B u
163	or
164	.B g.
165	.PP
166	Only the owner of a file (or the super-user) may change its mode.
167	.SH "SEE ALSO"
168	ls(1),
169	chmod(2),
170	chown (1),
171	stat(2),
172	umask(2)