sysconf.c revision 1.20
1 /* $NetBSD: sysconf.c,v 1.20 2004/11/10 04:02:52 lukem 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 1.20 2004/11/10 04:02:52 lukem 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 84 /* 1003.1 */ 85 case _SC_ARG_MAX: 86 mib[0] = CTL_KERN; 87 mib[1] = KERN_ARGMAX; 88 break; 89 case _SC_CHILD_MAX: 90 return (getrlimit(RLIMIT_NPROC, &rl) ? -1 : (long)rl.rlim_cur); 91 case _O_SC_CLK_TCK: 92 /* 93 * For applications compiled when CLK_TCK was a compile-time 94 * constant. 95 */ 96 return 100; 97 case _SC_CLK_TCK: 98 /* 99 * Has to be handled specially because it returns a 100 * struct clockinfo instead of an integer. Also, since 101 * this might be called often by some things that 102 * don't grok CLK_TCK can be a macro expanding to a 103 * function, cache the value. 104 */ 105 if (clk_tck == 0) { 106 mib[0] = CTL_KERN; 107 mib[1] = KERN_CLOCKRATE; 108 len = sizeof(struct clockinfo); 109 clk_tck = sysctl(mib, 2, &tmpclock, &len, NULL, 0) 110 == -1 ? -1 : tmpclock.hz; 111 } 112 return(clk_tck); 113 case _SC_JOB_CONTROL: 114 mib[0] = CTL_KERN; 115 mib[1] = KERN_JOB_CONTROL; 116 goto yesno; 117 case _SC_NGROUPS_MAX: 118 mib[0] = CTL_KERN; 119 mib[1] = KERN_NGROUPS; 120 break; 121 case _SC_OPEN_MAX: 122 return (getrlimit(RLIMIT_NOFILE, &rl) ? -1 : (long)rl.rlim_cur); 123 case _SC_STREAM_MAX: 124 mib[0] = CTL_USER; 125 mib[1] = USER_STREAM_MAX; 126 break; 127 case _SC_TZNAME_MAX: 128 mib[0] = CTL_USER; 129 mib[1] = USER_TZNAME_MAX; 130 break; 131 case _SC_SAVED_IDS: 132 mib[0] = CTL_KERN; 133 mib[1] = KERN_SAVED_IDS; 134 goto yesno; 135 case _SC_VERSION: 136 mib[0] = CTL_KERN; 137 mib[1] = KERN_POSIX1; 138 break; 139 140 /* 1003.1b */ 141 case _SC_PAGESIZE: 142 mib[0] = CTL_HW; 143 mib[1] = HW_PAGESIZE; 144 break; 145 case _SC_FSYNC: 146 mib[0] = CTL_KERN; 147 mib[1] = KERN_FSYNC; 148 goto yesno; 149 case _SC_SYNCHRONIZED_IO: 150 mib[0] = CTL_KERN; 151 mib[1] = KERN_SYNCHRONIZED_IO; 152 goto yesno; 153 case _SC_MAPPED_FILES: 154 mib[0] = CTL_KERN; 155 mib[1] = KERN_MAPPED_FILES; 156 goto yesno; 157 case _SC_MEMLOCK: 158 mib[0] = CTL_KERN; 159 mib[1] = KERN_MEMLOCK; 160 goto yesno; 161 case _SC_MEMLOCK_RANGE: 162 mib[0] = CTL_KERN; 163 mib[1] = KERN_MEMLOCK_RANGE; 164 goto yesno; 165 case _SC_MEMORY_PROTECTION: 166 mib[0] = CTL_KERN; 167 mib[1] = KERN_MEMORY_PROTECTION; 168 goto yesno; 169 case _SC_MONOTONIC_CLOCK: 170 mib[0] = CTL_KERN; 171 mib[1] = KERN_MONOTONIC_CLOCK; 172 goto yesno; 173 case _SC_SEMAPHORES: 174 mib[0] = CTL_KERN; 175 mib[1] = KERN_POSIX_SEMAPHORES; 176 goto yesno; 177 case _SC_TIMERS: 178 mib[0] = CTL_KERN; 179 mib[1] = KERN_POSIX_TIMERS; 180 goto yesno; 181 182 /* 1003.1c */ 183 case _SC_LOGIN_NAME_MAX: 184 mib[0] = CTL_KERN; 185 mib[1] = KERN_LOGIN_NAME_MAX; 186 break; 187 case _SC_THREADS: 188 mib[0] = CTL_KERN; 189 mib[1] = KERN_POSIX_THREADS; 190 goto yesno; 191 192 /* 1003.1j */ 193 case _SC_BARRIERS: 194 mib[0] = CTL_KERN; 195 mib[1] = KERN_POSIX_BARRIERS; 196 goto yesno; 197 case _SC_SPIN_LOCKS: 198 mib[0] = CTL_KERN; 199 mib[1] = KERN_POSIX_SPIN_LOCKS; 200 goto yesno; 201 /* Historical; Threads option in 1003.1-2001 */ 202 case _SC_READER_WRITER_LOCKS: 203 mib[0] = CTL_KERN; 204 mib[1] = KERN_POSIX_READER_WRITER_LOCKS; 205 goto yesno; 206 207 /* 1003.2 */ 208 case _SC_BC_BASE_MAX: 209 mib[0] = CTL_USER; 210 mib[1] = USER_BC_BASE_MAX; 211 break; 212 case _SC_BC_DIM_MAX: 213 mib[0] = CTL_USER; 214 mib[1] = USER_BC_DIM_MAX; 215 break; 216 case _SC_BC_SCALE_MAX: 217 mib[0] = CTL_USER; 218 mib[1] = USER_BC_SCALE_MAX; 219 break; 220 case _SC_BC_STRING_MAX: 221 mib[0] = CTL_USER; 222 mib[1] = USER_BC_STRING_MAX; 223 break; 224 case _SC_COLL_WEIGHTS_MAX: 225 mib[0] = CTL_USER; 226 mib[1] = USER_COLL_WEIGHTS_MAX; 227 break; 228 case _SC_EXPR_NEST_MAX: 229 mib[0] = CTL_USER; 230 mib[1] = USER_EXPR_NEST_MAX; 231 break; 232 case _SC_LINE_MAX: 233 mib[0] = CTL_USER; 234 mib[1] = USER_LINE_MAX; 235 break; 236 case _SC_RE_DUP_MAX: 237 mib[0] = CTL_USER; 238 mib[1] = USER_RE_DUP_MAX; 239 break; 240 case _SC_2_VERSION: 241 mib[0] = CTL_USER; 242 mib[1] = USER_POSIX2_VERSION; 243 break; 244 case _SC_2_C_BIND: 245 mib[0] = CTL_USER; 246 mib[1] = USER_POSIX2_C_BIND; 247 goto yesno; 248 case _SC_2_C_DEV: 249 mib[0] = CTL_USER; 250 mib[1] = USER_POSIX2_C_DEV; 251 goto yesno; 252 case _SC_2_CHAR_TERM: 253 mib[0] = CTL_USER; 254 mib[1] = USER_POSIX2_CHAR_TERM; 255 goto yesno; 256 case _SC_2_FORT_DEV: 257 mib[0] = CTL_USER; 258 mib[1] = USER_POSIX2_FORT_DEV; 259 goto yesno; 260 case _SC_2_FORT_RUN: 261 mib[0] = CTL_USER; 262 mib[1] = USER_POSIX2_FORT_RUN; 263 goto yesno; 264 case _SC_2_LOCALEDEF: 265 mib[0] = CTL_USER; 266 mib[1] = USER_POSIX2_LOCALEDEF; 267 goto yesno; 268 case _SC_2_SW_DEV: 269 mib[0] = CTL_USER; 270 mib[1] = USER_POSIX2_SW_DEV; 271 goto yesno; 272 case _SC_2_UPE: 273 mib[0] = CTL_USER; 274 mib[1] = USER_POSIX2_UPE; 275 goto yesno; 276 277 /* XPG 4.2 */ 278 case _SC_IOV_MAX: 279 mib[0] = CTL_KERN; 280 mib[1] = KERN_IOV_MAX; 281 break; 282 case _SC_XOPEN_SHM: 283 mib[0] = CTL_KERN; 284 mib[1] = KERN_SYSVSHM; 285 goto yesno; 286 287 /* 1003.1-2001, XSI Option Group */ 288 case _SC_ATEXIT_MAX: 289 mib[0] = CTL_USER; 290 mib[1] = USER_ATEXIT_MAX; 291 break; 292 293 /* 1003.1-2001, TSF */ 294 case _SC_GETGR_R_SIZE_MAX: 295 return _GETGR_R_SIZE_MAX; 296 case _SC_GETPW_R_SIZE_MAX: 297 return _GETPW_R_SIZE_MAX; 298 299 yesno: if (sysctl(mib, 2, &value, &len, NULL, 0) == -1) 300 return (-1); 301 if (value == 0) 302 return (-1); 303 return (value); 304 /*NOTREACHED*/ 305 break; 306 default: 307 errno = EINVAL; 308 return (-1); 309 } 310 return (sysctl(mib, 2, &value, &len, NULL, 0) == -1 ? -1 : value); 311 } 312
Indexes created Fri Sep 26 08:10:20 GMT 2025