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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 $
40 .Nd get configurable system variables
46 .Fn sysconf "int name"
48 This interface is defined by
50 A far more complete interface is available using
55 function provides a method for applications to determine the current
56 value of a configurable system limit or option variable.
59 argument specifies the system variable to be queried.
60 Symbolic constants for each name value are found in the include file
63 The available values are as follows:
68 The maximum bytes of argument to
71 The maximum number of simultaneous processes per user id.
73 The frequency of the statistics clock in ticks per second.
74 .It Li _SC_NGROUPS_MAX
75 The maximum number of supplemental groups.
77 The maximum number of open files per user id.
79 The minimum maximum number of streams that a process may have open
82 The minimum maximum number of types supported for the name of a
84 .It Li _SC_JOB_CONTROL
85 Return 1 if job control is available on this system, otherwise \-1.
87 Returns 1 if saved set-group and saved set-user ID is available,
94 .It Li _SC_BC_BASE_MAX
95 The maximum ibase/obase values in the
99 The maximum array size in the
102 .It Li _SC_BC_SCALE_MAX
103 The maximum scale value in the
106 .It Li _SC_BC_STRING_MAX
107 The maximum string length in the
110 .It Li _SC_COLL_WEIGHTS_MAX
111 The maximum number of weights that can be assigned to any entry of
112 the LC_COLLATE order keyword in the locale definition file.
113 .It Li _SC_EXPR_NEST_MAX
114 The maximum number of expressions that can be nested within
119 The maximum length in bytes of a text-processing utility's input
121 .It Li _SC_RE_DUP_MAX
122 The maximum number of repeated occurrences of a regular expression
123 permitted when using interval notation.
127 with which the system attempts to comply.
129 Return 1 if the system's C-language development facilities support the
130 C-Language Bindings Option, otherwise \-1.
132 Return 1 if the system supports the C-Language Development Utilities Option,
134 .It Li _SC_2_CHAR_TERM
135 Return 1 if the system supports at least one terminal type capable of
136 all operations described in
139 .It Li _SC_2_FORT_DEV
140 Return 1 if the system supports the FORTRAN Development Utilities Option,
142 .It Li _SC_2_FORT_RUN
143 Return 1 if the system supports the FORTRAN Runtime Utilities Option,
145 .It Li _SC_2_LOCALEDEF
146 Return 1 if the system supports the creation of locales, otherwise \-1.
148 Return 1 if the system supports the Software Development Utilities Option,
151 Return 1 if the system supports the User Portability Utilities Option,
157 is not successful, \-1 is returned and
159 is set appropriately.
160 Otherwise, if the variable is associated with functionality that is not
161 supported, \-1 is returned and
164 Otherwise, the current variable value is returned.
168 function may fail and set
170 for any of the errors specified for the library function
172 In addition, the following error may be reported:
182 The value for _SC_STREAM_MAX is a minimum maximum, and required to be
183 the same as ANSI C's FOPEN_MAX, so the returned value is a ridiculously
184 small and misleading number.
186 Except for the fact that values returned by
188 may change over the lifetime of the calling process,
189 this function conforms to
194 function first appeared in