sysconf.c revision 1.7 1 /* $NetBSD: sysconf.c,v 1.7 1998/03/30 14:33:22 kleink Exp $ */
2
3 /*-
4 * Copyright (c) 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Sean Eric Fagan of Cygnus Support.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 */
38
39 #include <sys/cdefs.h>
40 #if defined(LIBC_SCCS) && !defined(lint)
41 #if 0
42 static char sccsid[] = "@(#)sysconf.c 8.2 (Berkeley) 3/20/94";
43 #else
44 __RCSID("$NetBSD: sysconf.c,v 1.7 1998/03/30 14:33:22 kleink Exp $");
45 #endif
46 #endif /* LIBC_SCCS and not lint */
47
48 #include "namespace.h"
49 #include <sys/param.h>
50 #include <sys/sysctl.h>
51 #include <sys/time.h>
52 #include <sys/resource.h>
53
54 #include <errno.h>
55 #include <time.h>
56 #include <unistd.h>
57
58 #ifdef __weak_alias
59 __weak_alias(sysconf,_sysconf);
60 #endif
61
62 /*
63 * sysconf --
64 * get configurable system variables.
65 *
66 * XXX
67 * POSIX 1003.1 (ISO/IEC 9945-1, 4.8.1.3) states that the variable values
68 * not change during the lifetime of the calling process. This would seem
69 * to require that any change to system limits kill all running processes.
70 * A workaround might be to cache the values when they are first retrieved
71 * and then simply return the cached value on subsequent calls. This is
72 * less useful than returning up-to-date values, however.
73 */
74 long
75 sysconf(name)
76 int name;
77 {
78 struct rlimit rl;
79 size_t len;
80 int mib[2], value;
81
82 len = sizeof(value);
83
84 switch (name) {
85 /* 1003.1 */
86 case _SC_ARG_MAX:
87 mib[0] = CTL_KERN;
88 mib[1] = KERN_ARGMAX;
89 break;
90 case _SC_CHILD_MAX:
91 return (getrlimit(RLIMIT_NPROC, &rl) ? -1 : (long)rl.rlim_cur);
92 case _SC_CLK_TCK:
93 return (CLK_TCK);
94 case _SC_JOB_CONTROL:
95 mib[0] = CTL_KERN;
96 mib[1] = KERN_JOB_CONTROL;
97 goto yesno;
98 case _SC_NGROUPS_MAX:
99 mib[0] = CTL_KERN;
100 mib[1] = KERN_NGROUPS;
101 break;
102 case _SC_OPEN_MAX:
103 return (getrlimit(RLIMIT_NOFILE, &rl) ? -1 : (long)rl.rlim_cur);
104 case _SC_STREAM_MAX:
105 mib[0] = CTL_USER;
106 mib[1] = USER_STREAM_MAX;
107 break;
108 case _SC_TZNAME_MAX:
109 mib[0] = CTL_USER;
110 mib[1] = USER_TZNAME_MAX;
111 break;
112 case _SC_SAVED_IDS:
113 mib[0] = CTL_KERN;
114 mib[1] = KERN_SAVED_IDS;
115 goto yesno;
116 case _SC_VERSION:
117 mib[0] = CTL_KERN;
118 mib[1] = KERN_POSIX1;
119 break;
120
121 /* 1003.2 */
122 case _SC_BC_BASE_MAX:
123 mib[0] = CTL_USER;
124 mib[1] = USER_BC_BASE_MAX;
125 break;
126 case _SC_BC_DIM_MAX:
127 mib[0] = CTL_USER;
128 mib[1] = USER_BC_DIM_MAX;
129 break;
130 case _SC_BC_SCALE_MAX:
131 mib[0] = CTL_USER;
132 mib[1] = USER_BC_SCALE_MAX;
133 break;
134 case _SC_BC_STRING_MAX:
135 mib[0] = CTL_USER;
136 mib[1] = USER_BC_STRING_MAX;
137 break;
138 case _SC_COLL_WEIGHTS_MAX:
139 mib[0] = CTL_USER;
140 mib[1] = USER_COLL_WEIGHTS_MAX;
141 break;
142 case _SC_EXPR_NEST_MAX:
143 mib[0] = CTL_USER;
144 mib[1] = USER_EXPR_NEST_MAX;
145 break;
146 case _SC_LINE_MAX:
147 mib[0] = CTL_USER;
148 mib[1] = USER_LINE_MAX;
149 break;
150 case _SC_RE_DUP_MAX:
151 mib[0] = CTL_USER;
152 mib[1] = USER_RE_DUP_MAX;
153 break;
154 case _SC_2_VERSION:
155 mib[0] = CTL_USER;
156 mib[1] = USER_POSIX2_VERSION;
157 break;
158 case _SC_2_C_BIND:
159 mib[0] = CTL_USER;
160 mib[1] = USER_POSIX2_C_BIND;
161 goto yesno;
162 case _SC_2_C_DEV:
163 mib[0] = CTL_USER;
164 mib[1] = USER_POSIX2_C_DEV;
165 goto yesno;
166 case _SC_2_CHAR_TERM:
167 mib[0] = CTL_USER;
168 mib[1] = USER_POSIX2_CHAR_TERM;
169 goto yesno;
170 case _SC_2_FORT_DEV:
171 mib[0] = CTL_USER;
172 mib[1] = USER_POSIX2_FORT_DEV;
173 goto yesno;
174 case _SC_2_FORT_RUN:
175 mib[0] = CTL_USER;
176 mib[1] = USER_POSIX2_FORT_RUN;
177 goto yesno;
178 case _SC_2_LOCALEDEF:
179 mib[0] = CTL_USER;
180 mib[1] = USER_POSIX2_LOCALEDEF;
181 goto yesno;
182 case _SC_2_SW_DEV:
183 mib[0] = CTL_USER;
184 mib[1] = USER_POSIX2_SW_DEV;
185 goto yesno;
186 case _SC_2_UPE:
187 mib[0] = CTL_USER;
188 mib[1] = USER_POSIX2_UPE;
189 yesno: if (sysctl(mib, 2, &value, &len, NULL, 0) == -1)
190 return (-1);
191 if (value == 0)
192 return (-1);
193 return (value);
194 /*NOTREACHED*/
195 break;
196 default:
197 errno = EINVAL;
198 return (-1);
199 }
200 return (sysctl(mib, 2, &value, &len, NULL, 0) == -1 ? -1 : value);
201 }
202