xref: /freebsd/usr.bin/getconf/getconf.1 (revision a3e8fd0b7f663db7eafff527d5c3ca3bcfa8a537)
1.\"
2.\" Copyright 2000 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.\" $FreeBSD$
30.\"
31.Dd September 18, 2002
32.Dt GETCONF 1
33.Os
34.Sh NAME
35.Nm getconf
36.Nd retrieve standard configuration variables
37.Sh SYNOPSIS
38.Nm
39.Op Fl v Ar environment
40.Ar path_var
41.Ar file
42.Pp
43.Nm
44.Op Fl v Ar environment
45.Ar system_var
46.Sh DESCRIPTION
47The
48.Nm
49utility prints the value of a
50.Tn POSIX
51or
52.Tn X/Open
53path or system configuration variable to the standard output.
54If the specified variable is undefined, the string
55.Dq Li undefined
56is output.
57.Pp
58The first form of the command, with two mandatory
59arguments, retrieves file- and filesystem-specific
60configuration variables using
61.Xr pathconf 2 .
62The second form, with a single argument, retrieves system
63configuration variables using
64.Xr confstr 3
65and
66.Xr sysconf 3 ,
67depending on the type of variable.
68As an extension, the second form can also be used to query static limits from
69.Aq Pa limits.h .
70.Pp
71All
72.Xr sysconf 3
73and
74.Xr pathconf 2
75variables use the same name as the manifest constants defined in
76the relevant standard C-language bindings, including any leading
77underscore or prefix.
78That is to say,
79.Ar system_var
80might be
81.Dv ARG_MAX
82or
83.Dv _POSIX_VERSION ,
84as opposed to the
85.Xr sysconf 3
86names
87.Dv _SC_ARG_MAX
88or
89.Dv _SC_POSIX_VERSION .
90Variables retrieved from
91.Xr confstr 3
92have the leading
93.Ql _CS_
94stripped off; thus,
95.Dv _CS_PATH
96is queried by a
97.Ar system_var
98of
99.Dq Li PATH .
100.Ss Programming Environments
101The
102.Fl v Ar environment
103option specifies a
104.St -p1003.1-2001
105programming environment under which the values are to be queried.
106This option currently does nothing, but may in the future be used
107to select between 32-bit and 64-bit execution environments on platforms
108which support both.
109Specifying an environment which is not supported on the current execution
110platform gives undefined results.
111.Pp
112The standard programming environments are as follows:
113.Bl -tag -width ".Li POSIX_V6_LPBIG_OFFBIG" -offset indent
114.It Li POSIX_V6_ILP32_OFF32
115Exactly 32-bit integer, long, pointer, and file offset.
116.Sy Supported platforms :
117None.
118.It Li POSIX_V6_ILP32_OFFBIG
119Exactly 32-bit integer, long, and pointer; at least 64-bit file offset.
120.Sy Supported platforms :
121.Tn IA32 ,
122.Tn PowerPC .
123.It Li POSIX_V6_LP64_OFF64
124Exactly 32-bit integer; exactly 64-bit long, pointer, and file offset.
125.Sy Supported platforms :
126.Tn Alpha ,
127.Tn SPARC64 .
128.It Li POSIX_V6_LPBIG_OFFBIG
129At least 32-bit integer; at least 64-bit long, pointer, and file offset.
130.Sy Supported platforms :
131None.
132.El
133.Pp
134The command:
135.Bd -literal -offset indent
136getconf POSIX_V6_WIDTH_RESTRICTED_ENVS
137.Ed
138.Pp
139returns a newline-separated list of environments in which the width
140of certain fundamental types is no greater than the width of the native
141C type
142.Ql long .
143At present, all programming environments supported by
144.Fx
145have this property.
146Several of the
147.Xr confstr 3
148variables provide information on the necessary compiler and linker flags
149to use the standard programming environments described above.
150.Sh DIAGNOSTICS
151.Ex -std
152Use of a
153.Ar system_var
154or
155.Ar path_var
156which is completely unrecognized is considered an error,
157causing a diagnostic message to be written to standard error.
158One
159which is known but merely undefined does not result in an error
160indication.
161The
162.Nm
163command recognizes all of the variables defined for
164.St -p1003.1-2001 ,
165including those which are not currently implemented.
166.Sh EXAMPLES
167The command:
168.Bd -literal -offset indent
169getconf PATH
170.Ed
171.Pp
172will display the system default setting for the
173.Ev PATH
174environment variable.
175.Pp
176The command:
177.Bd -literal -offset indent
178getconf NAME_MAX /tmp
179.Ed
180.Pp
181will display the maximum length of a filename in the
182.Pa /tmp
183directory.
184.Pp
185The command:
186.Bd -literal -offset indent
187getconf -v POSIX_V6_LPBIG_OFFBIG LONG_MAX
188.Ed
189.Pp
190will display the maximum value of the C type
191.Ql long
192in the
193.Li POSIX_V6_LPBIG_OFFBIG
194programming environment,
195if the system supports that environment.
196.Sh SEE ALSO
197.Xr pathconf 2 ,
198.Xr confstr 3 ,
199.Xr sysconf 3
200.Sh STANDARDS
201The
202.Nm
203utility is expected to be compliant with
204.St -p1003.1-2001 .
205.Sh HISTORY
206The
207.Nm
208command first appeared in
209.Fx 5.0 .
210.Sh AUTHORS
211.An Garrett A. Wollman Aq wollman@lcs.mit.edu
212