gen/sysconf.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * Copyright (c) 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  *
  27  * This code is derived from software contributed to Berkeley by
  28  * Sean Eric Fagan of Cygnus Support.
  29  *
  30  * Redistribution and use in source and binary forms, with or without
  31  * modification, are permitted provided that the following conditions
  32  * are met:
  33  * 1. Redistributions of source code must retain the above copyright
  34  *    notice, this list of conditions and the following disclaimer.
  35  * 2. Redistributions in binary form must reproduce the above copyright
  36  *    notice, this list of conditions and the following disclaimer in the
  37  *    documentation and/or other materials provided with the distribution.
  38  * 3. All advertising materials mentioning features or use of this software
  39  *    must display the following acknowledgement:
  40  *      This product includes software developed by the University of
  41  *      California, Berkeley and its contributors.
  42  * 4. Neither the name of the University nor the names of its contributors
  43  *    may be used to endorse or promote products derived from this software
  44  *    without specific prior written permission.
  45  *
  46  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  47  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  48  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  49  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  50  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  51  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  52  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  53  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  54  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  55  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  56  * SUCH DAMAGE.
  57  */
  58
  59
  60 #include <sys/param.h>
  61 #include <sys/sysctl.h>
  62 #include <sys/time.h>
  63 #include <sys/resource.h>
  64
  65 #include <errno.h>
  66 #include <unistd.h>
  67
  68 /*
  69  * sysconf --
  70  *      get configurable system variables.
  71  *
  72  * XXX
  73  * POSIX 1003.1 (ISO/IEC 9945-1, 4.8.1.3) states that the variable values
  74  * not change during the lifetime of the calling process.  This would seem
  75  * to require that any change to system limits kill all running processes.
  76  * A workaround might be to cache the values when they are first retrieved
  77  * and then simply return the cached value on subsequent calls.  This is
  78  * less useful than returning up-to-date values, however.
  79  */
  80 long
  81 sysconf(name)
  82         int name;
  83 {
  84         struct rlimit rl;
  85         size_t len;
  86         int mib[2], value;
  87
  88         len = sizeof(value);
  89
  90         switch (name) {
  91 /* 1003.1 */
  92         case _SC_ARG_MAX:
  93                 mib[0] = CTL_KERN;
  94                 mib[1] = KERN_ARGMAX;
  95                 break;
  96         case _SC_CHILD_MAX:
  97                 return (getrlimit(RLIMIT_NPROC, &rl) ? -1 : rl.rlim_cur);
  98         case _SC_CLK_TCK:
  99                 return (CLK_TCK);
 100         case _SC_JOB_CONTROL:
 101                 mib[0] = CTL_KERN;
 102                 mib[1] = KERN_JOB_CONTROL;
 103                 goto yesno;
 104         case _SC_NGROUPS_MAX:
 105                 mib[0] = CTL_KERN;
 106                 mib[1] = KERN_NGROUPS;
 107                 break;
 108         case _SC_OPEN_MAX:
 109                 return (getrlimit(RLIMIT_NOFILE, &rl) ? -1 : rl.rlim_cur);
 110         case _SC_STREAM_MAX:
 111                 mib[0] = CTL_USER;
 112                 mib[1] = USER_STREAM_MAX;
 113                 break;
 114         case _SC_TZNAME_MAX:
 115                 mib[0] = CTL_USER;
 116                 mib[1] = USER_TZNAME_MAX;
 117                 break;
 118         case _SC_SAVED_IDS:
 119                 mib[0] = CTL_KERN;
 120                 mib[1] = KERN_SAVED_IDS;
 121                 goto yesno;
 122         case _SC_VERSION:
 123                 mib[0] = CTL_KERN;
 124                 mib[1] = KERN_POSIX1;
 125                 break;
 126
 127 /* 1003.2 */
 128         case _SC_BC_BASE_MAX:
 129                 mib[0] = CTL_USER;
 130                 mib[1] = USER_BC_BASE_MAX;
 131                 break;
 132         case _SC_BC_DIM_MAX:
 133                 mib[0] = CTL_USER;
 134                 mib[1] = USER_BC_DIM_MAX;
 135                 break;
 136         case _SC_BC_SCALE_MAX:
 137                 mib[0] = CTL_USER;
 138                 mib[1] = USER_BC_SCALE_MAX;
 139                 break;
 140         case _SC_BC_STRING_MAX:
 141                 mib[0] = CTL_USER;
 142                 mib[1] = USER_BC_STRING_MAX;
 143                 break;
 144         case _SC_COLL_WEIGHTS_MAX:
 145                 mib[0] = CTL_USER;
 146                 mib[1] = USER_COLL_WEIGHTS_MAX;
 147                 break;
 148         case _SC_EXPR_NEST_MAX:
 149                 mib[0] = CTL_USER;
 150                 mib[1] = USER_EXPR_NEST_MAX;
 151                 break;
 152         case _SC_LINE_MAX:
 153                 mib[0] = CTL_USER;
 154                 mib[1] = USER_LINE_MAX;
 155                 break;
 156         case _SC_PAGESIZE:
 157                 mib[0] = CTL_HW;
 158                 mib[1] = HW_PAGESIZE;
 159                 break;
 160         case _SC_RE_DUP_MAX:
 161                 mib[0] = CTL_USER;
 162                 mib[1] = USER_RE_DUP_MAX;
 163                 break;
 164         case _SC_2_VERSION:
 165                 mib[0] = CTL_USER;
 166                 mib[1] = USER_POSIX2_VERSION;
 167                 break;
 168         case _SC_2_C_BIND:
 169                 mib[0] = CTL_USER;
 170                 mib[1] = USER_POSIX2_C_BIND;
 171                 goto yesno;
 172         case _SC_2_C_DEV:
 173                 mib[0] = CTL_USER;
 174                 mib[1] = USER_POSIX2_C_DEV;
 175                 goto yesno;
 176         case _SC_2_CHAR_TERM:
 177                 mib[0] = CTL_USER;
 178                 mib[1] = USER_POSIX2_CHAR_TERM;
 179                 goto yesno;
 180         case _SC_2_FORT_DEV:
 181                 mib[0] = CTL_USER;
 182                 mib[1] = USER_POSIX2_FORT_DEV;
 183                 goto yesno;
 184         case _SC_2_FORT_RUN:
 185                 mib[0] = CTL_USER;
 186                 mib[1] = USER_POSIX2_FORT_RUN;
 187                 goto yesno;
 188         case _SC_2_LOCALEDEF:
 189                 mib[0] = CTL_USER;
 190                 mib[1] = USER_POSIX2_LOCALEDEF;
 191                 goto yesno;
 192         case _SC_2_SW_DEV:
 193                 mib[0] = CTL_USER;
 194                 mib[1] = USER_POSIX2_SW_DEV;
 195                 goto yesno;
 196         case _SC_2_UPE:
 197                 mib[0] = CTL_USER;
 198                 mib[1] = USER_POSIX2_UPE;
 199 yesno:          if (sysctl(mib, 2, &value, &len, NULL, 0) == -1)
 200                         return (-1);
 201                 if (value == 0)
 202                         return (-1);
 203                 return (value);
 204                 break;
 205         default:
 206                 errno = EINVAL;
 207                 return (-1);
 208         }
 209         return (sysctl(mib, 2, &value, &len, NULL, 0) == -1 ? -1 : value);
 210 }