sysconf.c revision 1.19
1 /* $NetBSD: sysconf.c,v 1.19 2003/08/07 16:42:57 agc 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. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 #if defined(LIBC_SCCS) && !defined(lint) 37 #if 0 38 static char sccsid[] = "@(#)sysconf.c 8.2 (Berkeley) 3/20/94"; 39 #else 40 __RCSID("$NetBSD: sysconf.c,v 1.19 2003/08/07 16:42:57 agc Exp $"); 41 #endif 42 #endif /* LIBC_SCCS and not lint */ 43 44 #include "namespace.h" 45 #include <sys/param.h> 46 #include <sys/sysctl.h> 47 #include <sys/time.h> 48 #include <sys/resource.h> 49 50 #include <errno.h> 51 #include <time.h> 52 #include <unistd.h> 53 54 #ifdef __weak_alias 55 __weak_alias(sysconf,__sysconf) 56 #endif 57 58 /* 59 * sysconf -- 60 * get configurable system variables. 61 * 62 * XXX 63 * POSIX 1003.1 (ISO/IEC 9945-1, 4.8.1.3) states that the variable values 64 * not change during the lifetime of the calling process. This would seem 65 * to require that any change to system limits kill all running processes. 66 * A workaround might be to cache the values when they are first retrieved 67 * and then simply return the cached value on subsequent calls. This is 68 * less useful than returning up-to-date values, however. 69 */ 70 long 71 sysconf(name) 72 int name; 73 { 74 struct rlimit rl; 75 size_t len; 76 int mib[2], value; 77 struct clockinfo tmpclock; 78 static int clk_tck; 79 80 len = sizeof(value); 81 82 switch (name) { 83 /* 1003.1 */ 84 case _SC_ARG_MAX: 85 mib[0] = CTL_KERN; 86 mib[1] = KERN_ARGMAX; 87 break; 88 case _SC_CHILD_MAX: 89 return (getrlimit(RLIMIT_NPROC, &rl) ? -1 : (long)rl.rlim_cur); 90 case _O_SC_CLK_TCK: 91 /* 92 * For applications compiled when CLK_TCK was a compile-time 93 * constant. 94 */ 95 return 100; 96 case _SC_CLK_TCK: 97 /* 98 * Has to be handled specially because it returns a 99 * struct clockinfo instead of an integer. Also, since 100 * this might be called often by some things that 101 * don't grok CLK_TCK can be a macro expanding to a 102 * function, cache the value. 103 */ 104 if (clk_tck == 0) { 105 mib[0] = CTL_KERN; 106 mib[1] = KERN_CLOCKRATE; 107 len = sizeof(struct clockinfo); 108 clk_tck = sysctl(mib, 2, &tmpclock, &len, NULL, 0) 109 == -1 ? -1 : tmpclock.hz; 110 } 111 return(clk_tck); 112 case _SC_JOB_CONTROL: 113 mib[0] = CTL_KERN; 114 mib[1] = KERN_JOB_CONTROL; 115 goto yesno; 116 case _SC_NGROUPS_MAX: 117 mib[0] = CTL_KERN; 118 mib[1] = KERN_NGROUPS; 119 break; 120 case _SC_OPEN_MAX: 121 return (getrlimit(RLIMIT_NOFILE, &rl) ? -1 : (long)rl.rlim_cur); 122 case _SC_STREAM_MAX: 123 mib[0] = CTL_USER; 124 mib[1] = USER_STREAM_MAX; 125 break; 126 case _SC_TZNAME_MAX: 127 mib[0] = CTL_USER; 128 mib[1] = USER_TZNAME_MAX; 129 break; 130 case _SC_SAVED_IDS: 131 mib[0] = CTL_KERN; 132 mib[1] = KERN_SAVED_IDS; 133 goto yesno; 134 case _SC_VERSION: 135 mib[0] = CTL_KERN; 136 mib[1] = KERN_POSIX1; 137 break; 138 139 /* 1003.1b */ 140 case _SC_PAGESIZE: 141 mib[0] = CTL_HW; 142 mib[1] = HW_PAGESIZE; 143 break; 144 case _SC_FSYNC: 145 mib[0] = CTL_KERN; 146 mib[1] = KERN_FSYNC; 147 goto yesno; 148 case _SC_SYNCHRONIZED_IO: 149 mib[0] = CTL_KERN; 150 mib[1] = KERN_SYNCHRONIZED_IO; 151 goto yesno; 152 case _SC_MAPPED_FILES: 153 mib[0] = CTL_KERN; 154 mib[1] = KERN_MAPPED_FILES; 155 goto yesno; 156 case _SC_MEMLOCK: 157 mib[0] = CTL_KERN; 158 mib[1] = KERN_MEMLOCK; 159 goto yesno; 160 case _SC_MEMLOCK_RANGE: 161 mib[0] = CTL_KERN; 162 mib[1] = KERN_MEMLOCK_RANGE; 163 goto yesno; 164 case _SC_MEMORY_PROTECTION: 165 mib[0] = CTL_KERN; 166 mib[1] = KERN_MEMORY_PROTECTION; 167 goto yesno; 168 case _SC_MONOTONIC_CLOCK: 169 mib[0] = CTL_KERN; 170 mib[1] = KERN_MONOTONIC_CLOCK; 171 goto yesno; 172 case _SC_SEMAPHORES: 173 mib[0] = CTL_KERN; 174 mib[1] = KERN_POSIX_SEMAPHORES; 175 goto yesno; 176 case _SC_TIMERS: 177 mib[0] = CTL_KERN; 178 mib[1] = KERN_POSIX_TIMERS; 179 goto yesno; 180 181 /* 1003.1c */ 182 case _SC_LOGIN_NAME_MAX: 183 mib[0] = CTL_KERN; 184 mib[1] = KERN_LOGIN_NAME_MAX; 185 break; 186 case _SC_THREADS: 187 mib[0] = CTL_KERN; 188 mib[1] = KERN_POSIX_THREADS; 189 goto yesno; 190 191 /* 1003.1j */ 192 case _SC_BARRIERS: 193 mib[0] = CTL_KERN; 194 mib[1] = KERN_POSIX_BARRIERS; 195 goto yesno; 196 case _SC_SPIN_LOCKS: 197 mib[0] = CTL_KERN; 198 mib[1] = KERN_POSIX_SPIN_LOCKS; 199 goto yesno; 200 /* Historical; Threads option in 1003.1-2001 */ 201 case _SC_READER_WRITER_LOCKS: 202 mib[0] = CTL_KERN; 203 mib[1] = KERN_POSIX_READER_WRITER_LOCKS; 204 goto yesno; 205 206 /* 1003.2 */ 207 case _SC_BC_BASE_MAX: 208 mib[0] = CTL_USER; 209 mib[1] = USER_BC_BASE_MAX; 210 break; 211 case _SC_BC_DIM_MAX: 212 mib[0] = CTL_USER; 213 mib[1] = USER_BC_DIM_MAX; 214 break; 215 case _SC_BC_SCALE_MAX: 216 mib[0] = CTL_USER; 217 mib[1] = USER_BC_SCALE_MAX; 218 break; 219 case _SC_BC_STRING_MAX: 220 mib[0] = CTL_USER; 221 mib[1] = USER_BC_STRING_MAX; 222 break; 223 case _SC_COLL_WEIGHTS_MAX: 224 mib[0] = CTL_USER; 225 mib[1] = USER_COLL_WEIGHTS_MAX; 226 break; 227 case _SC_EXPR_NEST_MAX: 228 mib[0] = CTL_USER; 229 mib[1] = USER_EXPR_NEST_MAX; 230 break; 231 case _SC_LINE_MAX: 232 mib[0] = CTL_USER; 233 mib[1] = USER_LINE_MAX; 234 break; 235 case _SC_RE_DUP_MAX: 236 mib[0] = CTL_USER; 237 mib[1] = USER_RE_DUP_MAX; 238 break; 239 case _SC_2_VERSION: 240 mib[0] = CTL_USER; 241 mib[1] = USER_POSIX2_VERSION; 242 break; 243 case _SC_2_C_BIND: 244 mib[0] = CTL_USER; 245 mib[1] = USER_POSIX2_C_BIND; 246 goto yesno; 247 case _SC_2_C_DEV: 248 mib[0] = CTL_USER; 249 mib[1] = USER_POSIX2_C_DEV; 250 goto yesno; 251 case _SC_2_CHAR_TERM: 252 mib[0] = CTL_USER; 253 mib[1] = USER_POSIX2_CHAR_TERM; 254 goto yesno; 255 case _SC_2_FORT_DEV: 256 mib[0] = CTL_USER; 257 mib[1] = USER_POSIX2_FORT_DEV; 258 goto yesno; 259 case _SC_2_FORT_RUN: 260 mib[0] = CTL_USER; 261 mib[1] = USER_POSIX2_FORT_RUN; 262 goto yesno; 263 case _SC_2_LOCALEDEF: 264 mib[0] = CTL_USER; 265 mib[1] = USER_POSIX2_LOCALEDEF; 266 goto yesno; 267 case _SC_2_SW_DEV: 268 mib[0] = CTL_USER; 269 mib[1] = USER_POSIX2_SW_DEV; 270 goto yesno; 271 case _SC_2_UPE: 272 mib[0] = CTL_USER; 273 mib[1] = USER_POSIX2_UPE; 274 goto yesno; 275 276 /* XPG 4.2 */ 277 case _SC_IOV_MAX: 278 mib[0] = CTL_KERN; 279 mib[1] = KERN_IOV_MAX; 280 break; 281 case _SC_XOPEN_SHM: 282 mib[0] = CTL_KERN; 283 mib[1] = KERN_SYSVSHM; 284 goto yesno; 285 286 /* 1003.1-2001, XSI Option Group */ 287 case _SC_ATEXIT_MAX: 288 mib[0] = CTL_USER; 289 mib[1] = USER_ATEXIT_MAX; 290 break; 291 292 yesno: if (sysctl(mib, 2, &value, &len, NULL, 0) == -1) 293 return (-1); 294 if (value == 0) 295 return (-1); 296 return (value); 297 /*NOTREACHED*/ 298 break; 299 default: 300 errno = EINVAL; 301 return (-1); 302 } 303 return (sysctl(mib, 2, &value, &len, NULL, 0) == -1 ? -1 : value); 304 } 305
Indexes created Thu Sep 25 16:09:42 GMT 2025