gen/sysconf.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * Copyright (c) 1993
  27  *      The Regents of the University of California.  All rights reserved.
  28  *
  29  * This code is derived from software contributed to Berkeley by
  30  * Sean Eric Fagan of Cygnus Support.
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions
  34  * are met:
  35  * 1. Redistributions of source code must retain the above copyright
  36  *    notice, this list of conditions and the following disclaimer.
  37  * 2. Redistributions in binary form must reproduce the above copyright
  38  *    notice, this list of conditions and the following disclaimer in the
  39  *    documentation and/or other materials provided with the distribution.
  40  * 3. All advertising materials mentioning features or use of this software
  41  *    must display the following acknowledgement:
  42  *      This product includes software developed by the University of
  43  *      California, Berkeley and its contributors.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  */
  60
  61
  62 #include <sys/param.h>
  63 #include <sys/sysctl.h>
  64 #include <sys/time.h>
  65 #include <sys/resource.h>
  66
  67 #include <errno.h>
  68 #include <unistd.h>
  69
  70 /*
  71  * sysconf --
  72  *      get configurable system variables.
  73  *
  74  * XXX
  75  * POSIX 1003.1 (ISO/IEC 9945-1, 4.8.1.3) states that the variable values
  76  * not change during the lifetime of the calling process.  This would seem
  77  * to require that any change to system limits kill all running processes.
  78  * A workaround might be to cache the values when they are first retrieved
  79  * and then simply return the cached value on subsequent calls.  This is
  80  * less useful than returning up-to-date values, however.
  81  */
  82 long
  83 sysconf(name)
  84         int name;
  85 {
  86         struct rlimit rl;
  87         size_t len;
  88         int mib[2], value;
  89
  90         len = sizeof(value);
  91
  92         switch (name) {
  93 /* 1003.1 */
  94         case _SC_ARG_MAX:
  95                 mib[0] = CTL_KERN;
  96                 mib[1] = KERN_ARGMAX;
  97                 break;
  98         case _SC_CHILD_MAX:
  99                 return (getrlimit(RLIMIT_NPROC, &rl) ? -1 : rl.rlim_cur);
 100         case _SC_CLK_TCK:
 101                 return (CLK_TCK);
 102         case _SC_JOB_CONTROL:
 103                 mib[0] = CTL_KERN;
 104                 mib[1] = KERN_JOB_CONTROL;
 105                 goto yesno;
 106         case _SC_NGROUPS_MAX:
 107                 mib[0] = CTL_KERN;
 108                 mib[1] = KERN_NGROUPS;
 109                 break;
 110         case _SC_OPEN_MAX:
 111                 return (getrlimit(RLIMIT_NOFILE, &rl) ? -1 : rl.rlim_cur);
 112         case _SC_STREAM_MAX:
 113                 mib[0] = CTL_USER;
 114                 mib[1] = USER_STREAM_MAX;
 115                 break;
 116         case _SC_TZNAME_MAX:
 117                 mib[0] = CTL_USER;
 118                 mib[1] = USER_TZNAME_MAX;
 119                 break;
 120         case _SC_SAVED_IDS:
 121                 mib[0] = CTL_KERN;
 122                 mib[1] = KERN_SAVED_IDS;
 123                 goto yesno;
 124         case _SC_VERSION:
 125                 mib[0] = CTL_KERN;
 126                 mib[1] = KERN_POSIX1;
 127                 break;
 128
 129 /* 1003.2 */
 130         case _SC_BC_BASE_MAX:
 131                 mib[0] = CTL_USER;
 132                 mib[1] = USER_BC_BASE_MAX;
 133                 break;
 134         case _SC_BC_DIM_MAX:
 135                 mib[0] = CTL_USER;
 136                 mib[1] = USER_BC_DIM_MAX;
 137                 break;
 138         case _SC_BC_SCALE_MAX:
 139                 mib[0] = CTL_USER;
 140                 mib[1] = USER_BC_SCALE_MAX;
 141                 break;
 142         case _SC_BC_STRING_MAX:
 143                 mib[0] = CTL_USER;
 144                 mib[1] = USER_BC_STRING_MAX;
 145                 break;
 146         case _SC_COLL_WEIGHTS_MAX:
 147                 mib[0] = CTL_USER;
 148                 mib[1] = USER_COLL_WEIGHTS_MAX;
 149                 break;
 150         case _SC_EXPR_NEST_MAX:
 151                 mib[0] = CTL_USER;
 152                 mib[1] = USER_EXPR_NEST_MAX;
 153                 break;
 154         case _SC_LINE_MAX:
 155                 mib[0] = CTL_USER;
 156                 mib[1] = USER_LINE_MAX;
 157                 break;
 158         case _SC_PAGESIZE:
 159                 mib[0] = CTL_HW;
 160                 mib[1] = HW_PAGESIZE;
 161                 break;
 162         case _SC_RE_DUP_MAX:
 163                 mib[0] = CTL_USER;
 164                 mib[1] = USER_RE_DUP_MAX;
 165                 break;
 166         case _SC_2_VERSION:
 167                 mib[0] = CTL_USER;
 168                 mib[1] = USER_POSIX2_VERSION;
 169                 break;
 170         case _SC_2_C_BIND:
 171                 mib[0] = CTL_USER;
 172                 mib[1] = USER_POSIX2_C_BIND;
 173                 goto yesno;
 174         case _SC_2_C_DEV:
 175                 mib[0] = CTL_USER;
 176                 mib[1] = USER_POSIX2_C_DEV;
 177                 goto yesno;
 178         case _SC_2_CHAR_TERM:
 179                 mib[0] = CTL_USER;
 180                 mib[1] = USER_POSIX2_CHAR_TERM;
 181                 goto yesno;
 182         case _SC_2_FORT_DEV:
 183                 mib[0] = CTL_USER;
 184                 mib[1] = USER_POSIX2_FORT_DEV;
 185                 goto yesno;
 186         case _SC_2_FORT_RUN:
 187                 mib[0] = CTL_USER;
 188                 mib[1] = USER_POSIX2_FORT_RUN;
 189                 goto yesno;
 190         case _SC_2_LOCALEDEF:
 191                 mib[0] = CTL_USER;
 192                 mib[1] = USER_POSIX2_LOCALEDEF;
 193                 goto yesno;
 194         case _SC_2_SW_DEV:
 195                 mib[0] = CTL_USER;
 196                 mib[1] = USER_POSIX2_SW_DEV;
 197                 goto yesno;
 198         case _SC_2_UPE:
 199                 mib[0] = CTL_USER;
 200                 mib[1] = USER_POSIX2_UPE;
 201 yesno:          if (sysctl(mib, 2, &value, &len, NULL, 0) == -1)
 202                         return (-1);
 203                 if (value == 0)
 204                         return (-1);
 205                 return (value);
 206                 break;
 207         default:
 208                 errno = EINVAL;
 209                 return (-1);
 210         }
 211         return (sysctl(mib, 2, &value, &len, NULL, 0) == -1 ? -1 : value);
 212 }