usr.bin/getconf/getconf.c

   1 /*
   2  * Copyright 2000 Massachusetts Institute of Technology
   3  *
   4  * Permission to use, copy, modify, and distribute this software and
   5  * its documentation for any purpose and without fee is hereby
   6  * granted, provided that both the above copyright notice and this
   7  * permission notice appear in all copies, that both the above
   8  * copyright notice and this permission notice appear in all
   9  * supporting documentation, and that the name of M.I.T. not be used
  10  * in advertising or publicity pertaining to distribution of the
  11  * software without specific, written prior permission.  M.I.T. makes
  12  * no representations about the suitability of this software for any
  13  * purpose.  It is provided "as is" without express or implied
  14  * warranty.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
  17  * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
  18  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
  20  * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  23  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  25  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  26  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #include <sys/cdefs.h>
  31 __FBSDID("$FreeBSD$");
  32
  33 #include <sys/types.h>
  34
  35 #include <err.h>
  36 #include <errno.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <sysexits.h>
  40 #include <unistd.h>
  41
  42 #include "getconf.h"
  43
  44 static void     do_confstr(const char *name, int key);
  45 static void     do_sysconf(const char *name, int key);
  46 static void     do_pathconf(const char *name, int key, const char *path);
  47
  48 static void
  49 usage(void)
  50 {
  51         fprintf(stderr,
  52 "usage: getconf [-v prog_env] system_var\n"
  53 "       getconf [-v prog_env] path_var pathname\n");
  54         exit(EX_USAGE);
  55 }
  56
  57 int
  58 main(int argc, char **argv)
  59 {
  60         int c, key, valid;
  61         const char *name, *vflag, *alt_path;
  62         intmax_t limitval;
  63
  64         vflag = NULL;
  65         while ((c = getopt(argc, argv, "v:")) != -1) {
  66                 switch (c) {
  67                 case 'v':
  68                         vflag = optarg;
  69                         break;
  70
  71                 default:
  72                         usage();
  73                 }
  74         }
  75
  76         if ((name = argv[optind]) == NULL)
  77                 usage();
  78
  79         if (vflag != NULL) {
  80                 if ((valid = find_progenv(vflag, &alt_path)) == 0)
  81                         errx(EX_USAGE, "invalid programming environment %s",
  82                              vflag);
  83                 if (valid > 0 && alt_path != NULL) {
  84                         if (argv[optind + 1] == NULL)
  85                                 execl(alt_path, "getconf", argv[optind],
  86                                       (char *)NULL);
  87                         else
  88                                 execl(alt_path, "getconf", argv[optind],
  89                                       argv[optind + 1], (char *)NULL);
  90
  91                         err(EX_OSERR, "execl: %s", alt_path);
  92                 }
  93                 if (valid < 0)
  94                         errx(EX_UNAVAILABLE, "environment %s is not available",
  95                              vflag);
  96         }
  97
  98         if (argv[optind + 1] == NULL) { /* confstr or sysconf */
  99                 if ((valid = find_limit(name, &limitval)) != 0) {
 100                         if (valid > 0)
 101                                 printf("%" PRIdMAX "\n", limitval);
 102                         else
 103                                 printf("undefined\n");
 104
 105                         return 0;
 106                 }
 107                 if ((valid = find_confstr(name, &key)) != 0) {
 108                         if (valid > 0)
 109                                 do_confstr(name, key);
 110                         else
 111                                 printf("undefined\n");
 112                 } else {
 113                         valid = find_sysconf(name, &key);
 114                         if (valid > 0) {
 115                                 do_sysconf(name, key);
 116                         } else if (valid < 0) {
 117                                 printf("undefined\n");
 118                         } else
 119                                 errx(EX_USAGE,
 120                                      "no such configuration parameter `%s'",
 121                                      name);
 122                 }
 123         } else {
 124                 valid = find_pathconf(name, &key);
 125                 if (valid != 0) {
 126                         if (valid > 0)
 127                                 do_pathconf(name, key, argv[optind + 1]);
 128                         else
 129                                 printf("undefined\n");
 130                 } else
 131                         errx(EX_USAGE,
 132                              "no such path configuration parameter `%s'",
 133                              name);
 134         }
 135         return 0;
 136 }
 137
 138 static void
 139 do_confstr(const char *name, int key)
 140 {
 141         size_t len;
 142         int savederr;
 143
 144         savederr = errno;
 145         errno = 0;
 146         len = confstr(key, 0, 0);
 147         if (len == 0) {
 148                 if (errno)
 149                         err(EX_OSERR, "confstr: %s", name);
 150                 else
 151                         printf("undefined\n");
 152         } else {
 153                 char buf[len + 1];
 154
 155                 confstr(key, buf, len);
 156                 printf("%s\n", buf);
 157         }
 158         errno = savederr;
 159 }
 160
 161 static void
 162 do_sysconf(const char *name, int key)
 163 {
 164         long value;
 165
 166         errno = 0;
 167         value = sysconf(key);
 168         if (value == -1 && errno != 0)
 169                 err(EX_OSERR, "sysconf: %s", name);
 170         else if (value == -1)
 171                 printf("undefined\n");
 172         else
 173                 printf("%ld\n", value);
 174 }
 175
 176 static void
 177 do_pathconf(const char *name, int key, const char *path)
 178 {
 179         long value;
 180
 181         errno = 0;
 182         value = pathconf(path, key);
 183         if (value == -1 && errno != 0)
 184                 err(EX_OSERR, "pathconf: %s", name);
 185         else if (value == -1)
 186                 printf("undefined\n");
 187         else
 188                 printf("%ld\n", value);
 189 }
 190