gen/sysconf.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1993
  24  *      The Regents of the University of California.  All rights reserved.
  25  *
  26  * This code is derived from software contributed to Berkeley by
  27  * Sean Eric Fagan of Cygnus Support.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  * 1. Redistributions of source code must retain the above copyright
  33  *    notice, this list of conditions and the following disclaimer.
  34  * 2. Redistributions in binary form must reproduce the above copyright
  35  *    notice, this list of conditions and the following disclaimer in the
  36  *    documentation and/or other materials provided with the distribution.
  37  * 3. All advertising materials mentioning features or use of this software
  38  *    must display the following acknowledgement:
  39  *      This product includes software developed by the University of
  40  *      California, Berkeley and its contributors.
  41  * 4. Neither the name of the University nor the names of its contributors
  42  *    may be used to endorse or promote products derived from this software
  43  *    without specific prior written permission.
  44  *
  45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  55  * SUCH DAMAGE.
  56  */
  57
  58
  59 #include <sys/param.h>
  60 #include <sys/sysctl.h>
  61 #include <sys/time.h>
  62 #include <sys/resource.h>
  63
  64 #include <errno.h>
  65 #include <unistd.h>
  66
  67 /*
  68  * sysconf --
  69  *      get configurable system variables.
  70  *
  71  * XXX
  72  * POSIX 1003.1 (ISO/IEC 9945-1, 4.8.1.3) states that the variable values
  73  * not change during the lifetime of the calling process.  This would seem
  74  * to require that any change to system limits kill all running processes.
  75  * A workaround might be to cache the values when they are first retrieved
  76  * and then simply return the cached value on subsequent calls.  This is
  77  * less useful than returning up-to-date values, however.
  78  */
  79 long
  80 sysconf(name)
  81         int name;
  82 {
  83         struct clockinfo clk;
  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_RE_DUP_MAX:
 157                 mib[0] = CTL_USER;
 158                 mib[1] = USER_RE_DUP_MAX;
 159                 break;
 160         case _SC_2_VERSION:
 161                 mib[0] = CTL_USER;
 162                 mib[1] = USER_POSIX2_VERSION;
 163                 break;
 164         case _SC_2_C_BIND:
 165                 mib[0] = CTL_USER;
 166                 mib[1] = USER_POSIX2_C_BIND;
 167                 goto yesno;
 168         case _SC_2_C_DEV:
 169                 mib[0] = CTL_USER;
 170                 mib[1] = USER_POSIX2_C_DEV;
 171                 goto yesno;
 172         case _SC_2_CHAR_TERM:
 173                 mib[0] = CTL_USER;
 174                 mib[1] = USER_POSIX2_CHAR_TERM;
 175                 goto yesno;
 176         case _SC_2_FORT_DEV:
 177                 mib[0] = CTL_USER;
 178                 mib[1] = USER_POSIX2_FORT_DEV;
 179                 goto yesno;
 180         case _SC_2_FORT_RUN:
 181                 mib[0] = CTL_USER;
 182                 mib[1] = USER_POSIX2_FORT_RUN;
 183                 goto yesno;
 184         case _SC_2_LOCALEDEF:
 185                 mib[0] = CTL_USER;
 186                 mib[1] = USER_POSIX2_LOCALEDEF;
 187                 goto yesno;
 188         case _SC_2_SW_DEV:
 189                 mib[0] = CTL_USER;
 190                 mib[1] = USER_POSIX2_SW_DEV;
 191                 goto yesno;
 192         case _SC_2_UPE:
 193                 mib[0] = CTL_USER;
 194                 mib[1] = USER_POSIX2_UPE;
 195 yesno:          if (sysctl(mib, 2, &value, &len, NULL, 0) == -1)
 196                         return (-1);
 197                 if (value == 0)
 198                         return (-1);
 199                 return (value);
 200                 break;
 201         default:
 202                 errno = EINVAL;
 203                 return (-1);
 204         }
 205         return (sysctl(mib, 2, &value, &len, NULL, 0) == -1 ? -1 : value);
 206 }