xref: /freebsd/lib/libc/gen/setmode.3 (revision 7d8f797b725e3efc0a4256554654780df83c456c)
1.\" Copyright (c) 1989, 1991, 1993
2.\"	The Regents of the University of California.  All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\"    notice, this list of conditions and the following disclaimer.
9.\" 2. Redistributions in binary form must reproduce the above copyright
10.\"    notice, this list of conditions and the following disclaimer in the
11.\"    documentation and/or other materials provided with the distribution.
12.\" 4. Neither the name of the University nor the names of its contributors
13.\"    may be used to endorse or promote products derived from this software
14.\"    without specific prior written permission.
15.\"
16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26.\" SUCH DAMAGE.
27.\"
28.\"     @(#)setmode.3	8.2 (Berkeley) 4/28/95
29.\" $FreeBSD$
30.\"
31.Dd February 22, 2015
32.Dt SETMODE 3
33.Os
34.Sh NAME
35.Nm getmode ,
36.Nm setmode
37.Nd modify mode bits
38.Sh LIBRARY
39.Lb libc
40.Sh SYNOPSIS
41.In unistd.h
42.Ft mode_t
43.Fn getmode "const void *set" "mode_t mode"
44.Ft void *
45.Fn setmode "const char *mode_str"
46.Sh DESCRIPTION
47The
48.Fn getmode
49function
50returns a copy of the file permission bits
51.Fa mode
52as altered by the values pointed to by
53.Fa set .
54While only the mode bits are altered, other parts of the file mode
55may be examined.
56.Pp
57The
58.Fn setmode
59function
60takes an absolute (octal) or symbolic value, as described in
61.Xr chmod 1 ,
62as an argument
63and returns a pointer to mode values to be supplied to
64.Fn getmode .
65Because some of the symbolic values are relative to the file
66creation mask,
67.Fn setmode
68may call
69.Xr umask 2 .
70If this occurs, the file creation mask will be restored before
71.Fn setmode
72returns.
73If the calling program changes the value of its file creation mask
74after calling
75.Fn setmode ,
76.Fn setmode
77must be called again if
78.Fn getmode
79is to modify future file modes correctly.
80.Pp
81If the mode passed to
82.Fn setmode
83is invalid or if memory cannot be allocated for the return value,
84.Fn setmode
85returns
86.Dv NULL .
87.Pp
88The value returned from
89.Fn setmode
90is obtained from
91.Fn malloc
92and should be returned to the system with
93.Fn free
94when the program is done with it, generally after a call to
95.Fn getmode .
96.Sh ERRORS
97The
98.Fn setmode
99function
100may fail and set errno for any of the errors specified for the library
101routine
102.Xr malloc 3
103or
104.Xr strtol 3 .
105In addition,
106.Fn setmode
107will fail and set
108.Va errno
109to:
110.Bl -tag -width Er
111.It Bq Er EINVAL
112The
113.Fa mode
114argument does not represent a valid mode.
115.El
116.Sh SEE ALSO
117.Xr chmod 1 ,
118.Xr stat 2 ,
119.Xr umask 2 ,
120.Xr malloc 3
121.Sh HISTORY
122The
123.Fn getmode
124and
125.Fn setmode
126functions first appeared in
127.Bx 4.4 .
128