sysconf.c revision 1.15
1 /* $NetBSD: sysconf.c,v 1.15 2002/06/23 19:19:01 perry 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 1.15 2002/06/23 19:19:01 perry 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 struct clockinfo tmpclock; 82 static int clk_tck; 83 84 len = sizeof(value); 85 86 switch (name) { 87 /* 1003.1 */ 88 case _SC_ARG_MAX: 89 mib[0] = CTL_KERN; 90 mib[1] = KERN_ARGMAX; 91 break; 92 case _SC_CHILD_MAX: 93 return (getrlimit(RLIMIT_NPROC, &rl) ? -1 : (long)rl.rlim_cur); 94 case _SC_CLK_TCK: 95 /* 96 * Has to be handled specially because it returns a 97 * struct clockinfo instead of an integer. Also, since 98 * this might be called often by some things that 99 * don't grok CLK_TCK can be a macro expanding to a 100 * function, cache the value. 101 */ 102 if (clk_tck == 0) { 103 mib[0] = CTL_KERN; 104 mib[1] = KERN_CLOCKRATE; 105 len = sizeof(struct clockinfo); 106 clk_tck = sysctl(mib, 2, &tmpclock, &len, NULL, 0) 107 == -1 ? -1 : tmpclock.hz; 108 } 109 return(clk_tck); 110 case _SC_JOB_CONTROL: 111 mib[0] = CTL_KERN; 112 mib[1] = KERN_JOB_CONTROL; 113 goto yesno; 114 case _SC_NGROUPS_MAX: 115 mib[0] = CTL_KERN; 116 mib[1] = KERN_NGROUPS; 117 break; 118 case _SC_OPEN_MAX: 119 return (getrlimit(RLIMIT_NOFILE, &rl) ? -1 : (long)rl.rlim_cur); 120 case _SC_STREAM_MAX: 121 mib[0] = CTL_USER; 122 mib[1] = USER_STREAM_MAX; 123 break; 124 case _SC_TZNAME_MAX: 125 mib[0] = CTL_USER; 126 mib[1] = USER_TZNAME_MAX; 127 break; 128 case _SC_SAVED_IDS: 129 mib[0] = CTL_KERN; 130 mib[1] = KERN_SAVED_IDS; 131 goto yesno; 132 case _SC_VERSION: 133 mib[0] = CTL_KERN; 134 mib[1] = KERN_POSIX1; 135 break; 136 137 /* 1003.1b */ 138 case _SC_PAGESIZE: 139 mib[0] = CTL_HW; 140 mib[1] = HW_PAGESIZE; 141 break; 142 case _SC_FSYNC: 143 mib[0] = CTL_KERN; 144 mib[1] = KERN_FSYNC; 145 goto yesno; 146 case _SC_SYNCHRONIZED_IO: 147 mib[0] = CTL_KERN; 148 mib[1] = KERN_SYNCHRONIZED_IO; 149 goto yesno; 150 case _SC_MAPPED_FILES: 151 mib[0] = CTL_KERN; 152 mib[1] = KERN_MAPPED_FILES; 153 goto yesno; 154 case _SC_MEMLOCK: 155 mib[0] = CTL_KERN; 156 mib[1] = KERN_MEMLOCK; 157 goto yesno; 158 case _SC_MEMLOCK_RANGE: 159 mib[0] = CTL_KERN; 160 mib[1] = KERN_MEMLOCK_RANGE; 161 goto yesno; 162 case _SC_MEMORY_PROTECTION: 163 mib[0] = CTL_KERN; 164 mib[1] = KERN_MEMORY_PROTECTION; 165 goto yesno; 166 case _SC_MONOTONIC_CLOCK: 167 mib[0] = CTL_KERN; 168 mib[1] = KERN_MONOTONIC_CLOCK; 169 goto yesno; 170 171 /* 1003.1c */ 172 case _SC_LOGIN_NAME_MAX: 173 mib[0] = CTL_KERN; 174 mib[1] = KERN_LOGIN_NAME_MAX; 175 break; 176 177 /* 1003.2 */ 178 case _SC_BC_BASE_MAX: 179 mib[0] = CTL_USER; 180 mib[1] = USER_BC_BASE_MAX; 181 break; 182 case _SC_BC_DIM_MAX: 183 mib[0] = CTL_USER; 184 mib[1] = USER_BC_DIM_MAX; 185 break; 186 case _SC_BC_SCALE_MAX: 187 mib[0] = CTL_USER; 188 mib[1] = USER_BC_SCALE_MAX; 189 break; 190 case _SC_BC_STRING_MAX: 191 mib[0] = CTL_USER; 192 mib[1] = USER_BC_STRING_MAX; 193 break; 194 case _SC_COLL_WEIGHTS_MAX: 195 mib[0] = CTL_USER; 196 mib[1] = USER_COLL_WEIGHTS_MAX; 197 break; 198 case _SC_EXPR_NEST_MAX: 199 mib[0] = CTL_USER; 200 mib[1] = USER_EXPR_NEST_MAX; 201 break; 202 case _SC_LINE_MAX: 203 mib[0] = CTL_USER; 204 mib[1] = USER_LINE_MAX; 205 break; 206 case _SC_RE_DUP_MAX: 207 mib[0] = CTL_USER; 208 mib[1] = USER_RE_DUP_MAX; 209 break; 210 case _SC_2_VERSION: 211 mib[0] = CTL_USER; 212 mib[1] = USER_POSIX2_VERSION; 213 break; 214 case _SC_2_C_BIND: 215 mib[0] = CTL_USER; 216 mib[1] = USER_POSIX2_C_BIND; 217 goto yesno; 218 case _SC_2_C_DEV: 219 mib[0] = CTL_USER; 220 mib[1] = USER_POSIX2_C_DEV; 221 goto yesno; 222 case _SC_2_CHAR_TERM: 223 mib[0] = CTL_USER; 224 mib[1] = USER_POSIX2_CHAR_TERM; 225 goto yesno; 226 case _SC_2_FORT_DEV: 227 mib[0] = CTL_USER; 228 mib[1] = USER_POSIX2_FORT_DEV; 229 goto yesno; 230 case _SC_2_FORT_RUN: 231 mib[0] = CTL_USER; 232 mib[1] = USER_POSIX2_FORT_RUN; 233 goto yesno; 234 case _SC_2_LOCALEDEF: 235 mib[0] = CTL_USER; 236 mib[1] = USER_POSIX2_LOCALEDEF; 237 goto yesno; 238 case _SC_2_SW_DEV: 239 mib[0] = CTL_USER; 240 mib[1] = USER_POSIX2_SW_DEV; 241 goto yesno; 242 case _SC_2_UPE: 243 mib[0] = CTL_USER; 244 mib[1] = USER_POSIX2_UPE; 245 goto yesno; 246 247 /* XPG 4.2 */ 248 case _SC_IOV_MAX: 249 mib[0] = CTL_KERN; 250 mib[1] = KERN_IOV_MAX; 251 break; 252 case _SC_XOPEN_SHM: 253 mib[0] = CTL_KERN; 254 mib[1] = KERN_SYSVSHM; 255 yesno: if (sysctl(mib, 2, &value, &len, NULL, 0) == -1) 256 return (-1); 257 if (value == 0) 258 return (-1); 259 return (value); 260 /*NOTREACHED*/ 261 break; 262 default: 263 errno = EINVAL; 264 return (-1); 265 } 266 return (sysctl(mib, 2, &value, &len, NULL, 0) == -1 ? -1 : value); 267 } 268
Indexes created Thu Sep 25 15:09:46 GMT 2025