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  * $FreeBSD: head/usr.bin/getconf/getconf.c 164945 2006-12-06 12:00:26Z maxim $
  30  */
  31
  32 #include <sys/types.h>
  33
  34 #include <err.h>
  35 #include <errno.h>
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <sysexits.h>
  39 #include <unistd.h>
  40
  41 #include "getconf.h"
  42
  43 static void     do_confstr(const char *name, int key);
  44 static void     do_sysconf(const char *name, int key);
  45 static void     do_pathconf(const char *name, int key, const char *path);
  46
  47 static void
  48 usage(void)
  49 {
  50         fprintf(stderr,
  51 "usage: getconf [-v prog_env] system_var\n"
  52 "       getconf [-v prog_env] path_var pathname\n");
  53         exit(EX_USAGE);
  54 }
  55
  56 int
  57 main(int argc, char **argv)
  58 {
  59         int c, key, valid;
  60         const char *name, *vflag, *alt_path;
  61         intmax_t limitval;
  62
  63         vflag = NULL;
  64         while ((c = getopt(argc, argv, "v:")) != -1) {
  65                 switch (c) {
  66                 case 'v':
  67                         vflag = optarg;
  68                         break;
  69
  70                 default:
  71                         usage();
  72                 }
  73         }
  74
  75         if ((name = argv[optind]) == NULL)
  76                 usage();
  77
  78         if (vflag != NULL) {
  79                 if ((valid = find_progenv(vflag, &alt_path)) == 0)
  80                         errx(EX_USAGE, "invalid programming environment %s",
  81                              vflag);
  82                 if (valid > 0 && alt_path != NULL) {
  83                         if (argv[optind + 1] == NULL)
  84                                 execl(alt_path, "getconf", argv[optind],
  85                                       NULL);
  86                         else
  87                                 execl(alt_path, "getconf", argv[optind],
  88                                       argv[optind + 1], NULL);
  89
  90                         err(EX_OSERR, "execl: %s", alt_path);
  91                 }
  92                 if (valid < 0)
  93                         errx(EX_UNAVAILABLE, "environment %s is not available",
  94                              vflag);
  95         }
  96
  97         if (argv[optind + 1] == NULL) { /* confstr or sysconf */
  98                 if ((valid = find_limit(name, &limitval)) != 0) {
  99                         if (valid > 0)
 100                                 printf("%" PRIdMAX "\n", limitval);
 101                         else
 102                                 printf("undefined\n");
 103
 104                         return 0;
 105                 }
 106                 if ((valid = find_confstr(name, &key)) != 0) {
 107                         if (valid > 0)
 108                                 do_confstr(name, key);
 109                         else
 110                                 printf("undefined\n");
 111                 } else {
 112                         valid = find_sysconf(name, &key);
 113                         if (valid > 0) {
 114                                 do_sysconf(name, key);
 115                         } else if (valid < 0) {
 116                                 printf("undefined\n");
 117                         } else
 118                                 errx(EX_USAGE,
 119                                      "no such configuration parameter `%s'",
 120                                      name);
 121                 }
 122         } else {
 123                 valid = find_pathconf(name, &key);
 124                 if (valid != 0) {
 125                         if (valid > 0)
 126                                 do_pathconf(name, key, argv[optind + 1]);
 127                         else
 128                                 printf("undefined\n");
 129                 } else
 130                         errx(EX_USAGE,
 131                              "no such path configuration parameter `%s'",
 132                              name);
 133         }
 134         return 0;
 135 }
 136
 137 static void
 138 do_confstr(const char *name, int key)
 139 {
 140         size_t len;
 141         int savederr;
 142
 143         savederr = errno;
 144         errno = 0;
 145         len = confstr(key, 0, 0);
 146         if (len == 0) {
 147                 if (errno)
 148                         err(EX_OSERR, "confstr: %s", name);
 149                 else
 150                         printf("undefined\n");
 151         } else {
 152                 char buf[len + 1];
 153
 154                 confstr(key, buf, len);
 155                 printf("%s\n", buf);
 156         }
 157         errno = savederr;
 158 }
 159
 160 static void
 161 do_sysconf(const char *name, int key)
 162 {
 163         long value;
 164
 165         errno = 0;
 166         value = sysconf(key);
 167         if (value == -1 && errno != 0)
 168                 err(EX_OSERR, "sysconf: %s", name);
 169         else if (value == -1)
 170                 printf("undefined\n");
 171         else
 172                 printf("%ld\n", value);
 173 }
 174
 175 static void
 176 do_pathconf(const char *name, int key, const char *path)
 177 {
 178         long value;
 179
 180         errno = 0;
 181         value = pathconf(path, key);
 182         if (value == -1 && errno != 0)
 183                 err(EX_OSERR, "pathconf: %s", name);
 184         else if (value == -1)
 185                 printf("undefined\n");
 186         else
 187                 printf("%ld\n", value);
 188 }
 189