xref: /freebsd/usr.bin/getconf/getconf.1 (revision cbd30a72ca196976c1c700400ecd424baa1b9c16)
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29.\" $FreeBSD$
30.\"
31.Dd August 8, 2016
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.Nm
43.Op Fl v Ar environment
44.Ar system_var
45.Sh DESCRIPTION
46The
47.Nm
48utility prints the value of a
49.Tn POSIX
50or
51.Tn X/Open
52path or system configuration variable to the standard output.
53If the specified variable is undefined, the string
54.Dq Li undefined
55is output.
56.Pp
57The first form of the command, with two mandatory
58arguments, retrieves file- and file system-specific
59configuration variables using
60.Xr pathconf 2 .
61The second form, with a single argument, retrieves system
62configuration variables using
63.Xr confstr 3
64and
65.Xr sysconf 3 ,
66depending on the type of variable.
67As an extension, the second form can also be used to query static limits from
68.In limits.h .
69.Pp
70All
71.Xr sysconf 3
72and
73.Xr pathconf 2
74variables use the same name as the manifest constants defined in
75the relevant standard C-language bindings, including any leading
76underscore or prefix.
77That is to say,
78.Ar system_var
79might be
80.Dv ARG_MAX
81or
82.Dv _POSIX_VERSION ,
83as opposed to the
84.Xr sysconf 3
85names
86.Dv _SC_ARG_MAX
87or
88.Dv _SC_POSIX_VERSION .
89Variables retrieved from
90.Xr confstr 3
91have the leading
92.Ql _CS_
93stripped off; thus,
94.Dv _CS_PATH
95is queried by a
96.Ar system_var
97of
98.Dq Li PATH .
99.Ss Programming Environments
100The
101.Fl v Ar environment
102option specifies a
103.St -p1003.1-2001
104programming environment under which the values are to be queried.
105This option currently does nothing, but may in the future be used
106to select between 32-bit and 64-bit execution environments on platforms
107which support both.
108Specifying an environment which is not supported on the current execution
109platform gives undefined results.
110.Pp
111The standard programming environments are as follows:
112.Bl -tag -width ".Li POSIX_V6_LPBIG_OFFBIG" -offset indent
113.It Li POSIX_V6_ILP32_OFF32
114Exactly 32-bit integer, long, pointer, and file offset.
115.Sy Supported platforms :
116None.
117.It Li POSIX_V6_ILP32_OFFBIG
118Exactly 32-bit integer, long, and pointer; at least 64-bit file offset.
119.Sy Supported platforms :
120.Tn IA32 ,
121.Tn PowerPC .
122.It Li POSIX_V6_LP64_OFF64
123Exactly 32-bit integer; exactly 64-bit long, pointer, and file offset.
124.Sy Supported platforms :
125.Tn AMD64 ,
126.Tn SPARC64 .
127.It Li POSIX_V6_LPBIG_OFFBIG
128At least 32-bit integer; at least 64-bit long, pointer, and file offset.
129.Sy Supported platforms :
130None.
131.El
132.Pp
133The command:
134.Pp
135.Dl "getconf POSIX_V6_WIDTH_RESTRICTED_ENVS"
136.Pp
137returns a newline-separated list of environments in which the width
138of certain fundamental types is no greater than the width of the native
139C type
140.Vt long .
141At present, all programming environments supported by
142.Fx
143have this property.
144Several of the
145.Xr confstr 3
146variables provide information on the necessary compiler and linker flags
147to use the standard programming environments described above.
148.Sh EXIT STATUS
149.Ex -std
150.Sh EXAMPLES
151The command:
152.Pp
153.Dl "getconf PATH"
154.Pp
155will display the system default setting for the
156.Ev PATH
157environment variable.
158.Pp
159The command:
160.Pp
161.Dl "getconf NAME_MAX /tmp"
162.Pp
163will display the maximum length of a filename in the
164.Pa /tmp
165directory.
166.Pp
167The command:
168.Pp
169.Dl "getconf -v POSIX_V6_LPBIG_OFFBIG LONG_MAX"
170.Pp
171will display the maximum value of the C type
172.Vt long
173in the
174.Li POSIX_V6_LPBIG_OFFBIG
175programming environment,
176if the system supports that environment.
177.Sh DIAGNOSTICS
178Use of a
179.Ar system_var
180or
181.Ar path_var
182which is completely unrecognized is considered an error,
183causing a diagnostic message to be written to standard error.
184One
185which is known but merely undefined does not result in an error
186indication.
187The
188.Nm
189utility recognizes all of the variables defined for
190.St -p1003.1-2001 ,
191including those which are not currently implemented.
192.Sh SEE ALSO
193.Xr pathconf 2 ,
194.Xr confstr 3 ,
195.Xr sysconf 3
196.Sh STANDARDS
197The
198.Nm
199utility is expected to be compliant with
200.St -p1003.1-2001 .
201.Sh HISTORY
202The
203.Nm
204utility first appeared in
205.Fx 5.0 .
206.Sh AUTHORS
207.An Garrett A. Wollman Aq Mt wollman@lcs.mit.edu
208