lib/libc/gen/confstr.c

   1 /*-
   2  * Copyright (c) 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)confstr.c        8.1 (Berkeley) 6/4/93
  30  * $FreeBSD: src/lib/libc/gen/confstr.c,v 1.10 2007/01/09 00:27:53 imp Exp $
  31  * $DragonFly: src/lib/libc/gen/confstr.c,v 1.5 2006/12/06 16:33:29 tgen Exp $
  32  */
  33
  34 #include <sys/param.h>
  35
  36 #include <errno.h>
  37 #include <limits.h>
  38 #include <paths.h>
  39 #include <string.h>
  40 #include <unistd.h>
  41
  42
  43 size_t
  44 confstr(int name, char *buf, size_t len)
  45 {
  46         const char *p;
  47         const char UPE[] = "unsupported programming environment";
  48
  49         switch (name) {
  50         case _CS_PATH:
  51                 p = _PATH_STDPATH;
  52                 goto docopy;
  53
  54                 /*
  55                  * POSIX/SUS ``Programming Environments'' stuff
  56                  *
  57                  * We don't support more than one programming environment
  58                  * on any platform (yet), so we just return the empty
  59                  * string for the environment we are compiled for,
  60                  * and the string "unsupported programming environment"
  61                  * for anything else.  (The Standard says that if these
  62                  * values are used on a system which does not support
  63                  * this environment -- determined via sysconf() -- then
  64                  * the value we return is unspecified.  So, we return
  65                  * something which will cause obvious breakage.)
  66                  */
  67         case _CS_POSIX_V6_ILP32_OFF32_CFLAGS:
  68         case _CS_POSIX_V6_ILP32_OFF32_LDFLAGS:
  69         case _CS_POSIX_V6_ILP32_OFF32_LIBS:
  70         case _CS_POSIX_V6_LPBIG_OFFBIG_CFLAGS:
  71         case _CS_POSIX_V6_LPBIG_OFFBIG_LDFLAGS:
  72         case _CS_POSIX_V6_LPBIG_OFFBIG_LIBS:
  73                 /*
  74                  * These two environments are never supported.
  75                  */
  76                 p = UPE;
  77                 goto docopy;
  78
  79         case _CS_POSIX_V6_ILP32_OFFBIG_CFLAGS:
  80         case _CS_POSIX_V6_ILP32_OFFBIG_LDFLAGS:
  81         case _CS_POSIX_V6_ILP32_OFFBIG_LIBS:
  82                 if (sizeof(long) * CHAR_BIT == 32 &&
  83                     sizeof(off_t) > sizeof(long))
  84                         p = "";
  85                 else
  86                         p = UPE;
  87                 goto docopy;
  88
  89         case _CS_POSIX_V6_LP64_OFF64_CFLAGS:
  90         case _CS_POSIX_V6_LP64_OFF64_LDFLAGS:
  91         case _CS_POSIX_V6_LP64_OFF64_LIBS:
  92                 if (sizeof(long) * CHAR_BIT >= 64 &&
  93                     sizeof(void *) * CHAR_BIT >= 64 &&
  94                     sizeof(int) * CHAR_BIT >= 32 &&
  95                     sizeof(off_t) >= sizeof(long))
  96                         p = "";
  97                 else
  98                         p = UPE;
  99                 goto docopy;
 100
 101         case _CS_POSIX_V6_WIDTH_RESTRICTED_ENVS:
 102                 /* XXX - should have more complete coverage */
 103                 if (sizeof(long) * CHAR_BIT >= 64)
 104                         p = "_POSIX_V6_LP64_OFF64";
 105                 else
 106                         p = "_POSIX_V6_ILP32_OFFBIG";
 107                 goto docopy;
 108
 109 docopy:
 110                 if (len != 0 && buf != NULL)
 111                         strlcpy(buf, p, len);
 112                 return (strlen(p) + 1);
 113
 114         default:
 115                 errno = EINVAL;
 116                 return (0);
 117         }
 118         /* NOTREACHED */
 119 }