posix/getconf.c

   1 /* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ansidecl.h>
  20 #include <unistd.h>
  21 #include <errno.h>
  22 #include <string.h>
  23 #include <stdlib.h>
  24 #include <stdio.h>
  25
  26 struct conf
  27   {
  28     CONST char *name;
  29     CONST int call_name;
  30     CONST enum { SYSCONF, CONFSTR, PATHCONF } call;
  31   };
  32
  33 static struct conf vars[] =
  34   {
  35     { "LINK_MAX", _PC_LINK_MAX, PATHCONF },
  36     { "MAX_CANON", _PC_MAX_CANON, PATHCONF },
  37     { "MAX_INPUT", _PC_MAX_INPUT, PATHCONF },
  38     { "NAME_MAX", _PC_NAME_MAX, PATHCONF },
  39     { "PATH_MAX", _PC_PATH_MAX, PATHCONF },
  40     { "PIPE_BUF", _PC_PIPE_BUF, PATHCONF },
  41     { "_POSIX_CHOWN_RESTRICTED", _PC_CHOWN_RESTRICTED, PATHCONF },
  42     { "_POSIX_NO_TRUNC", _PC_NO_TRUNC, PATHCONF },
  43     { "_POSIX_VDISABLE", _PC_VDISABLE, PATHCONF },
  44
  45     { "ARG_MAX", _SC_ARG_MAX, SYSCONF },
  46     { "CHILD_MAX", _SC_CHILD_MAX, SYSCONF },
  47     { "CLK_TCK", _SC_CLK_TCK, SYSCONF },
  48     { "NGROUPS_MAX", _SC_NGROUPS_MAX, SYSCONF },
  49     { "OPEN_MAX", _SC_OPEN_MAX, SYSCONF },
  50     { "_POSIX_JOB_CONTROL", _SC_JOB_CONTROL, SYSCONF },
  51     { "_POSIX_SAVED_IDS", _SC_SAVED_IDS, SYSCONF },
  52     { "_POSIX_VERSION", _SC_VERSION, SYSCONF },
  53
  54     { "PATH", _CS_PATH, CONFSTR },
  55
  56     { NULL, 0, SYSCONF }
  57   };
  58
  59 static CONST char *program;
  60
  61 static void
  62 DEFUN_VOID(usage)
  63 {
  64   fprintf (stderr, "Usage: %s variable_name [pathname]\n", program);
  65   exit (2);
  66 }
  67
  68 int
  69 DEFUN(main, (argc, argv), int argc AND char **argv)
  70 {
  71   register CONST struct conf *c;
  72
  73   program = strrchr (argv[0], '/');
  74   if (program == NULL)
  75     program = argv[0];
  76   else
  77     ++program;
  78
  79   if (argc < 2 || argc > 3)
  80     usage ();
  81
  82   for (c = vars; c->name != NULL; ++c)
  83     if (!strcmp (c->name, argv[1]))
  84       {
  85         long int value;
  86         size_t clen;
  87         char *cvalue;
  88         switch (c->call)
  89           {
  90           case PATHCONF:
  91             if (argc < 3)
  92               usage ();
  93             value = pathconf (argv[2], c->call_name);
  94             if (value == -1)
  95               {
  96                 fprintf (stderr, "%s: pathconf: %s: %s\n",
  97                          program, argv[2], strerror (errno));
  98                 exit (3);
  99               }
 100             printf ("%ld\n", value);
 101             exit (0);
 102
 103           case SYSCONF:
 104             if (argc > 2)
 105               usage ();
 106             value = sysconf (c->call_name);
 107             printf ("%ld\n", value);
 108             exit (0);
 109
 110           case CONFSTR:
 111             if (argc > 2)
 112               usage ();
 113             clen = confstr (c->call_name, (char *) NULL, 0);
 114             cvalue = (char *) malloc (clen);
 115             if (cvalue == NULL)
 116               {
 117                 fprintf (stderr, "%s: malloc: %s\n",
 118                          program, strerror (errno));
 119                 exit (3);
 120               }
 121             if (confstr (c->call_name, cvalue, clen) != clen)
 122               {
 123                 fprintf (stderr, "%s: confstr: %s\n",
 124                          program, strerror (errno));
 125                 exit (3);
 126               }
 127             printf ("%.*s\n", (int) clen, cvalue);
 128             exit (0);
 129           }
 130       }
 131
 132   fprintf (stderr, "%s: Unrecognized variable `%s'\n", program, argv[1]);
 133   exit (2);
 134 }