xref: /freebsd/usr.bin/getconf/getconf.1 (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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29.\" $FreeBSD$
30.\"
31.Dd September 15, 2017
32.Dt GETCONF 1
33.Os
34.Sh NAME
35.Nm getconf
36.Nd retrieve standard configuration variables
37.Sh SYNOPSIS
38.Nm
39.Fl a
40.Op Ar file
41.Nm
42.Op Fl v Ar environment
43.Ar path_var
44.Ar file
45.Nm
46.Op Fl v Ar environment
47.Ar system_var
48.Sh DESCRIPTION
49The
50.Nm
51utility prints the values of
52.Tn POSIX
53or
54.Tn X/Open
55path or system configuration variables to the standard output.
56If a variable is undefined, the string
57.Dq Li undefined
58is output.
59.Pp
60The first form of the command displays all of the path or system configuration
61variables to standard output.
62If
63.Ar file
64is provided,
65all path configuration variables are reported for
66.Ar file
67using
68.Xr pathconf 2 .
69Otherwise,
70all system configuration variables are reported using
71.Xr confstr 3
72and
73.Xr sysconf 3 .
74.Pp
75The second form of the command, with two mandatory
76arguments, retrieves file- and file system-specific
77configuration variables using
78.Xr pathconf 2 .
79The third form, with a single argument, retrieves system
80configuration variables using
81.Xr confstr 3
82and
83.Xr sysconf 3 ,
84depending on the type of variable.
85As an extension, the second form can also be used to query static limits from
86.In limits.h .
87.Pp
88All
89.Xr sysconf 3
90and
91.Xr pathconf 2
92variables use the same name as the manifest constants defined in
93the relevant standard C-language bindings, including any leading
94underscore or prefix.
95That is to say,
96.Ar system_var
97might be
98.Dv ARG_MAX
99or
100.Dv _POSIX_VERSION ,
101as opposed to the
102.Xr sysconf 3
103names
104.Dv _SC_ARG_MAX
105or
106.Dv _SC_POSIX_VERSION .
107Variables retrieved from
108.Xr confstr 3
109have the leading
110.Ql _CS_
111stripped off; thus,
112.Dv _CS_PATH
113is queried by a
114.Ar system_var
115of
116.Dq Li PATH .
117.Ss Programming Environments
118The
119.Fl v Ar environment
120option specifies a
121.St -p1003.1-2001
122programming environment under which the values are to be queried.
123This option currently does nothing, but may in the future be used
124to select between 32-bit and 64-bit execution environments on platforms
125which support both.
126Specifying an environment which is not supported on the current execution
127platform gives undefined results.
128.Pp
129The standard programming environments are as follows:
130.Bl -tag -width ".Li POSIX_V6_LPBIG_OFFBIG" -offset indent
131.It Li POSIX_V6_ILP32_OFF32
132Exactly 32-bit integer, long, pointer, and file offset.
133.Sy Supported platforms :
134None.
135.It Li POSIX_V6_ILP32_OFFBIG
136Exactly 32-bit integer, long, and pointer; at least 64-bit file offset.
137.Sy Supported platforms :
138.Tn IA32 ,
139.Tn PowerPC .
140.It Li POSIX_V6_LP64_OFF64
141Exactly 32-bit integer; exactly 64-bit long, pointer, and file offset.
142.Sy Supported platforms :
143.Tn AMD64 ,
144.Tn SPARC64 .
145.It Li POSIX_V6_LPBIG_OFFBIG
146At least 32-bit integer; at least 64-bit long, pointer, and file offset.
147.Sy Supported platforms :
148None.
149.El
150.Pp
151The command:
152.Pp
153.Dl "getconf POSIX_V6_WIDTH_RESTRICTED_ENVS"
154.Pp
155returns a newline-separated list of environments in which the width
156of certain fundamental types is no greater than the width of the native
157C type
158.Vt long .
159At present, all programming environments supported by
160.Fx
161have this property.
162Several of the
163.Xr confstr 3
164variables provide information on the necessary compiler and linker flags
165to use the standard programming environments described above.
166.Sh EXIT STATUS
167.Ex -std
168.Sh EXAMPLES
169The command:
170.Pp
171.Dl "getconf PATH"
172.Pp
173will display the system default setting for the
174.Ev PATH
175environment variable.
176.Pp
177The command:
178.Pp
179.Dl "getconf NAME_MAX /tmp"
180.Pp
181will display the maximum length of a filename in the
182.Pa /tmp
183directory.
184.Pp
185The command:
186.Pp
187.Dl "getconf -v POSIX_V6_LPBIG_OFFBIG LONG_MAX"
188.Pp
189will display the maximum value of the C type
190.Vt long
191in the
192.Li POSIX_V6_LPBIG_OFFBIG
193programming environment,
194if the system supports that environment.
195.Sh DIAGNOSTICS
196Use of a
197.Ar system_var
198or
199.Ar path_var
200which is completely unrecognized is considered an error,
201causing a diagnostic message to be written to standard error.
202One
203which is known but merely undefined does not result in an error
204indication.
205The
206.Nm
207utility recognizes all of the variables defined for
208.St -p1003.1-2001 ,
209including those which are not currently implemented.
210.Sh SEE ALSO
211.Xr pathconf 2 ,
212.Xr confstr 3 ,
213.Xr sysconf 3
214.Sh STANDARDS
215The
216.Nm
217utility is expected to be compliant with
218.St -p1003.1-2001 .
219.Sh HISTORY
220The
221.Nm
222utility first appeared in
223.Fx 5.0 .
224.Sh AUTHORS
225.An Garrett A. Wollman Aq Mt wollman@lcs.mit.edu
226