Source

inferno / man / 1 / chmod

Full commit
.TH CHMOD 1
.SH NAME
chmod \- change file mode (permissions)
.SH SYNOPSIS
.B chmod
.I mode
.I file ...
.SH DESCRIPTION
.I Chmod
changes the mode (permissions) of each
.I file
according to
.IR mode ,
which may be an octal number or a symbolic change to the existing mode.
.PP
A
.I mode
can be numerically formed as the
.SM OR
of the following octal values (a leading
.B 8r
is ignored):
.TF 0000
.TP
0400
read by owner
.TP
0200
write by owner
.TP
0100
execute (search in directory) by owner
.TP
0070
read, write, execute (search) by group
.TP
0007
read, write, execute (search) by others
.PD
.PP
A symbolic
.I mode
has the form:
.IP
.RI [ who ]
.I 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
.BR ugo .
If
.I who
is omitted, the default is
.BR a .
.PP
The
.I op
field can be:
.B +
to add 
.I permission
to the file's mode,
.B -
to take away
.IR permission ,
.B =
to assign
.I permission
absolutely (all other bits being reset).
.PP
The
.I permission
field is any combination of the letters
.B r
(read),
.B w
(write),
.B x
(execute),
.B a
(append only),
.B l
(exclusive access), and
.B t
(temporary, not archived).
.SH SOURCE
.B /appl/cmd/chmod.b
.PP
.SH "SEE ALSO"
.IR chgrp (1),
.IR ls (1),
.IR sys-stat (2)
.SH BUGS
The interpretation of the modes is limited on some host operating systems,
particularly variants of Windows.