2 .\" The Regents of the University of California. All rights reserved.
4 .\" Redistribution and use in source and binary forms, with or without
5 .\" modification, are permitted provided that the following conditions
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 .\" 3. All advertising materials mentioning features or use of this software
13 .\" must display the following acknowledgement:
14 .\" This product includes software developed by the University of
15 .\" California, Berkeley and its contributors.
16 .\" 4. Neither the name of the University nor the names of its contributors
17 .\" may be used to endorse or promote products derived from this software
18 .\" without specific prior written permission.
20 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 .\" @(#)sysconf.3 8.3 (Berkeley) 4/19/94
33 .\" $FreeBSD: src/lib/libc/gen/sysconf.3,v 1.8.2.6 2001/12/14 18:33:51 ru Exp $
34 .\" $DragonFly: src/lib/libc/gen/sysconf.3,v 1.3 2004/11/09 17:52:45 joerg Exp $
41 .Nd get configurable system variables
47 .Fn sysconf "int name"
49 This interface is defined by
51 A far more complete interface is available using
56 function provides a method for applications to determine the current
57 value of a configurable system limit or option variable.
60 argument specifies the system variable to be queried.
61 Symbolic constants for each name value are found in the include file
64 The available values are as follows:
69 The maximum bytes of argument to
72 The maximum number of simultaneous processes per user id.
74 The frequency of the statistics clock in ticks per second.
76 The maximum number of elements in the I/O vector used by
82 .It Li _SC_NGROUPS_MAX
83 The maximum number of supplemental groups.
85 The maximum number of open files per user id.
87 The minimum maximum number of streams that a process may have open
90 The minimum maximum number of types supported for the name of a
92 .It Li _SC_JOB_CONTROL
93 Return 1 if job control is available on this system, otherwise \-1.
95 Returns 1 if saved set-group and saved set-user ID is available,
100 with which the system
102 .It Li _SC_BC_BASE_MAX
103 The maximum ibase/obase values in the
106 .It Li _SC_BC_DIM_MAX
107 The maximum array size in the
110 .It Li _SC_BC_SCALE_MAX
111 The maximum scale value in the
114 .It Li _SC_BC_STRING_MAX
115 The maximum string length in the
118 .It Li _SC_COLL_WEIGHTS_MAX
119 The maximum number of weights that can be assigned to any entry of
120 the LC_COLLATE order keyword in the locale definition file.
121 .It Li _SC_EXPR_NEST_MAX
122 The maximum number of expressions that can be nested within
127 The maximum length in bytes of a text-processing utility's input
129 .It Li _SC_RE_DUP_MAX
130 The maximum number of repeated occurrences of a regular expression
131 permitted when using interval notation.
135 with which the system attempts to comply.
137 Return 1 if the system's C-language development facilities support the
138 C-Language Bindings Option, otherwise \-1.
140 Return 1 if the system supports the C-Language Development Utilities Option,
142 .It Li _SC_2_CHAR_TERM
143 Return 1 if the system supports at least one terminal type capable of
144 all operations described in
147 .It Li _SC_2_FORT_DEV
148 Return 1 if the system supports the FORTRAN Development Utilities Option,
150 .It Li _SC_2_FORT_RUN
151 Return 1 if the system supports the FORTRAN Runtime Utilities Option,
153 .It Li _SC_2_LOCALEDEF
154 Return 1 if the system supports the creation of locales, otherwise \-1.
156 Return 1 if the system supports the Software Development Utilities Option,
159 Return 1 if the system supports the User Portability Utilities Option,
165 is not successful, \-1 is returned and
167 is set appropriately.
168 Otherwise, if the variable is associated with functionality that is not
169 supported, \-1 is returned and
172 Otherwise, the current variable value is returned.
176 function may fail and set
178 for any of the errors specified for the library function
180 In addition, the following error may be reported:
190 The value for _SC_STREAM_MAX is a minimum maximum, and required to be
191 the same as ANSI C's FOPEN_MAX, so the returned value is a ridiculously
192 small and misleading number.
194 Except for the fact that values returned by
196 may change over the lifetime of the calling process,
197 this function conforms to
202 function first appeared in