xref: /freebsd/lib/libc/gen/check_utility_compat.3 (revision 59c8e88e72633afbc47a4ace0d2170d00d51f7dc)
1.\"
2.\" Copyright 2002 Massachusetts Institute of Technology
3.\"
4.\" Permission to use, copy, modify, and distribute this software and
5.\" its documentation for any purpose and without fee is hereby
6.\" granted, provided that both the above copyright notice and this
7.\" permission notice appear in all copies, that both the above
8.\" copyright notice and this permission notice appear in all
9.\" supporting documentation, and that the name of M.I.T. not be used
10.\" in advertising or publicity pertaining to distribution of the
11.\" software without specific, written prior permission.  M.I.T. makes
12.\" no representations about the suitability of this software for any
13.\" purpose.  It is provided "as is" without express or implied
14.\" warranty.
15.\"
16.\" THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
17.\" ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
18.\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
19.\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
20.\" SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22.\" LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
23.\" USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24.\" ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
26.\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27.\" SUCH DAMAGE.
28.\"
29.Dd October 27, 2002
30.Dt CHECK_UTILITY_COMPAT 3
31.Os
32.Sh NAME
33.Nm check_utility_compat
34.Nd "determine whether a utility should be compatible"
35.Sh LIBRARY
36.Lb libc
37.Sh SYNOPSIS
38.In unistd.h
39.Ft int
40.Fn check_utility_compat "const char *utility"
41.Sh DESCRIPTION
42The
43.Fn check_utility_compat
44function checks whether
45.Fa utility
46should behave in a traditional
47.Pq Fx 4.7 Ns -compatible
48manner, or in accordance with
49.St -p1003.1-2001 .
50The configuration is given as a comma-separated list of utility names;
51if the list is present but empty, all supported utilities assume their
52most compatible mode.
53The
54.Fn check_utility_compat
55function first checks for an environment variable named
56.Ev _COMPAT_FreeBSD_4 .
57If that environment variable does not exist, then
58.Fn check_utility_compat
59will attempt to read the contents of a symbolic link named
60.Pa /etc/compat-FreeBSD-4-util .
61If no configuration is found, compatibility mode is disabled.
62.Sh RETURN VALUES
63The
64.Fn check_utility_compat
65function returns zero if
66.Fa utility
67should implement strict
68.St -p1003.1-2001
69behavior, and nonzero otherwise.
70.Sh FILES
71.Bl -tag -width ".Pa /etc/compat-FreeBSD-4-util"
72.It Pa /etc/compat-FreeBSD-4-util
73If present, a symbolic link whose expansion gives system-wide default settings
74for the
75.Fn check_utility_compat
76function.
77.El
78.Sh ERRORS
79No errors are detected.
80.Sh HISTORY
81The
82.Fn check_utility_compat
83function first appeared in
84.Fx 5.0 .
85.Sh AUTHORS
86This manual page was written by
87.An Garrett Wollman Aq Mt wollman@FreeBSD.org .
88