system_cmds/getconf.tproj/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: src/usr.bin/getconf/getconf.c,v 1.10 2006/12/06 12:00:26 maxim Exp $");
  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 <libiosexec.h>
  43
  44 #include "getconf.h"
  45
  46 static void     do_confstr(const char *name, int key);
  47 static void     do_sysconf(const char *name, int key);
  48 static void     do_pathconf(const char *name, int key, const char *path);
  49
  50 static void
  51 usage(void)
  52 {
  53         fprintf(stderr,
  54 "usage: getconf [-v prog_env] system_var\n"
  55 "       getconf [-v prog_env] path_var pathname\n");
  56         exit(EX_USAGE);
  57 }
  58
  59 int
  60 main(int argc, char **argv)
  61 {
  62         int c, key, valid;
  63         const char *name, *vflag, *alt_path;
  64         intmax_t limitval;
  65
  66         vflag = NULL;
  67         while ((c = getopt(argc, argv, "v:")) != -1) {
  68                 switch (c) {
  69                 case 'v':
  70                         vflag = optarg;
  71                         break;
  72
  73                 default:
  74                         usage();
  75                 }
  76         }
  77
  78         if ((name = argv[optind]) == NULL)
  79                 usage();
  80
  81         if (vflag != NULL) {
  82                 if ((valid = find_progenv(vflag, &alt_path)) == 0)
  83                         errx(EX_USAGE, "invalid programming environment %s",
  84                              vflag);
  85                 if (valid > 0 && alt_path != NULL) {
  86                         if (argv[optind + 1] == NULL)
  87                                 execl(alt_path, "getconf", argv[optind],
  88                                       (char *)NULL);
  89                         else
  90                                 execl(alt_path, "getconf", argv[optind],
  91                                       argv[optind + 1], (char *)NULL);
  92
  93                         err(EX_OSERR, "execl: %s", alt_path);
  94                 }
  95                 if (valid < 0)
  96                         errx(EX_UNAVAILABLE, "environment %s is not available",
  97                              vflag);
  98         }
  99
 100         if (argv[optind + 1] == NULL) { /* confstr or sysconf */
 101                 if ((valid = find_limit(name, &limitval)) != 0) {
 102                         if (valid > 0)
 103                                 printf("%" PRIdMAX "\n", limitval);
 104                         else
 105                                 printf("undefined\n");
 106
 107                         return 0;
 108                 }
 109                 if ((valid = find_confstr(name, &key)) != 0) {
 110                         if (valid > 0)
 111                                 do_confstr(name, key);
 112                         else
 113                                 printf("undefined\n");
 114                 } else {
 115                         valid = find_sysconf(name, &key);
 116                         if (valid > 0) {
 117                                 do_sysconf(name, key);
 118                         } else if (valid < 0) {
 119                                 printf("undefined\n");
 120                         } else
 121                                 errx(EX_USAGE,
 122                                      "no such configuration parameter `%s'",
 123                                      name);
 124                 }
 125         } else {
 126                 valid = find_pathconf(name, &key);
 127                 if (valid != 0) {
 128                         if (valid > 0)
 129                                 do_pathconf(name, key, argv[optind + 1]);
 130                         else
 131                                 printf("undefined\n");
 132                 } else
 133                         errx(EX_USAGE,
 134                              "no such path configuration parameter `%s'",
 135                              name);
 136         }
 137         return 0;
 138 }
 139
 140 static void
 141 do_confstr(const char *name, int key)
 142 {
 143         size_t len;
 144         int savederr;
 145
 146         savederr = errno;
 147         errno = 0;
 148         len = confstr(key, 0, 0);
 149         if (len == 0) {
 150                 if (errno)
 151                         err(EX_OSERR, "confstr: %s", name);
 152                 else
 153                         printf("undefined\n");
 154         } else {
 155                 char buf[len + 1];
 156
 157                 confstr(key, buf, len);
 158                 printf("%s\n", buf);
 159         }
 160         errno = savederr;
 161 }
 162
 163 static void
 164 do_sysconf(const char *name, int key)
 165 {
 166         long value;
 167
 168         errno = 0;
 169         value = sysconf(key);
 170         if (value == -1 && errno != 0)
 171                 err(EX_OSERR, "sysconf: %s", name);
 172         else if (value == -1)
 173                 printf("undefined\n");
 174         else
 175                 printf("%ld\n", value);
 176 }
 177
 178 static void
 179 do_pathconf(const char *name, int key, const char *path)
 180 {
 181         long value;
 182
 183         errno = 0;
 184         value = pathconf(path, key);
 185         if (value == -1 && errno != 0)
 186                 err(EX_OSERR, "pathconf: %s", name);
 187         else if (value == -1)
 188                 printf("undefined\n");
 189         else
 190                 printf("%ld\n", value);
 191 }