posix/confstr.c

   1 /* Copyright (C) 1991, 1996, 1997, 2000, 2001 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 Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the 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    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <stddef.h>
  20 #include <errno.h>
  21 #include <unistd.h>
  22 #include <string.h>
  23 #include <confstr.h>
  24
  25 /* If BUF is not NULL and LEN > 0, fill in at most LEN - 1 bytes
  26    of BUF with the value corresponding to NAME and zero-terminate BUF.
  27    Return the number of bytes required to hold NAME's entire value.  */
  28 size_t
  29 confstr (name, buf, len)
  30      int name;
  31      char *buf;
  32      size_t len;
  33 {
  34   const char *string;
  35   size_t string_len;
  36
  37   switch (name)
  38     {
  39     case _CS_PATH:
  40       {
  41         static const char cs_path[] = CS_PATH;
  42         string = cs_path;
  43         string_len = sizeof (cs_path);
  44       }
  45       break;
  46
  47     case _CS_V6_WIDTH_RESTRICTED_ENVS:
  48       /* We have to return a newline-separated list of named of
  49          programming environements in which the widths of blksize_t,
  50          cc_t, mode_t, nfds_t, pid_t, ptrdiff_t, size_t, speed_t,
  51          ssize_t, suseconds_t, tcflag_t, useconds_t, wchar_t, and
  52          wint_t types are no greater than the width of type long.
  53
  54          Currently this means all environment which the system allows.  */
  55       {
  56         static const char restenvs[] =
  57 #if _POSIX_V6_ILP32_OFF32 > 0
  58         "_POSIX_V6_ILP32_OFF32"
  59 #endif
  60 #if _POSIX_V6_ILP32_OFFBIG > 0
  61 # if _POSIX_V6_ILP32_OFF32 > 0
  62         "\n"
  63 # endif
  64         "_POSIX_V6_ILP32_OFFBIG"
  65 #endif
  66 #if _POSIX_V6_LP64_OFF64 > 0
  67 # if _POSIX_V6_ILP32_OFF32 > 0 || _POSIX_V6_ILP32_OFFBIG > 0
  68         "\n"
  69 # endif
  70         "_POSIX_V6_LP64_OFF64"
  71 #endif
  72 #if _POSIX_V6_LPBIG_OFFBIG > 0
  73 # if _POSIX_V6_ILP32_OFF32 > 0 || _POSIX_V6_ILP32_OFFBIG > 0 \
  74      || _POSIX_V6_LP64_OFF64 > 0
  75         "\n"
  76 # endif
  77         "_POSIX_V6_LPBIG_OFFBIG"
  78 #endif
  79           ;
  80         string = restenvs;
  81         string_len = sizeof (restenvs);
  82       }
  83       break;
  84
  85     case _CS_XBS5_ILP32_OFFBIG_CFLAGS:
  86     case _CS_POSIX_V6_ILP32_OFFBIG_CFLAGS:
  87     case _CS_LFS_CFLAGS:
  88 #if _XBS5_LP64_OFF64 == -1 && _XBS5_LPBIG_OFFBIG == -1 && _XBS5_ILP32_OFFBIG == 1
  89       /* Signal that we want the new ABI.  */
  90       {
  91         static const char file_offset[] = "-D_FILE_OFFSET_BITS=64";
  92         string = file_offset;
  93         string_len = sizeof (file_offset);
  94       }
  95       break;
  96 #endif
  97       /* FALLTHROUGH */
  98
  99     case _CS_LFS_LINTFLAGS:
 100     case _CS_LFS_LDFLAGS:
 101     case _CS_LFS_LIBS:
 102     case _CS_LFS64_CFLAGS:
 103     case _CS_LFS64_LINTFLAGS:
 104     case _CS_LFS64_LDFLAGS:
 105     case _CS_LFS64_LIBS:
 106
 107     case _CS_XBS5_ILP32_OFF32_CFLAGS:
 108     case _CS_XBS5_ILP32_OFF32_LDFLAGS:
 109     case _CS_XBS5_ILP32_OFF32_LIBS:
 110     case _CS_XBS5_ILP32_OFF32_LINTFLAGS:
 111     case _CS_XBS5_ILP32_OFFBIG_LDFLAGS:
 112     case _CS_XBS5_ILP32_OFFBIG_LIBS:
 113     case _CS_XBS5_ILP32_OFFBIG_LINTFLAGS:
 114     case _CS_XBS5_LP64_OFF64_CFLAGS:
 115     case _CS_XBS5_LP64_OFF64_LDFLAGS:
 116     case _CS_XBS5_LP64_OFF64_LIBS:
 117     case _CS_XBS5_LP64_OFF64_LINTFLAGS:
 118     case _CS_XBS5_LPBIG_OFFBIG_CFLAGS:
 119     case _CS_XBS5_LPBIG_OFFBIG_LDFLAGS:
 120     case _CS_XBS5_LPBIG_OFFBIG_LIBS:
 121     case _CS_XBS5_LPBIG_OFFBIG_LINTFLAGS:
 122
 123     case _CS_POSIX_V6_ILP32_OFF32_CFLAGS:
 124     case _CS_POSIX_V6_ILP32_OFF32_LDFLAGS:
 125     case _CS_POSIX_V6_ILP32_OFF32_LIBS:
 126     case _CS_POSIX_V6_ILP32_OFF32_LINTFLAGS:
 127     case _CS_POSIX_V6_ILP32_OFFBIG_LDFLAGS:
 128     case _CS_POSIX_V6_ILP32_OFFBIG_LIBS:
 129     case _CS_POSIX_V6_ILP32_OFFBIG_LINTFLAGS:
 130     case _CS_POSIX_V6_LP64_OFF64_CFLAGS:
 131     case _CS_POSIX_V6_LP64_OFF64_LDFLAGS:
 132     case _CS_POSIX_V6_LP64_OFF64_LIBS:
 133     case _CS_POSIX_V6_LP64_OFF64_LINTFLAGS:
 134     case _CS_POSIX_V6_LPBIG_OFFBIG_CFLAGS:
 135     case _CS_POSIX_V6_LPBIG_OFFBIG_LDFLAGS:
 136     case _CS_POSIX_V6_LPBIG_OFFBIG_LIBS:
 137     case _CS_POSIX_V6_LPBIG_OFFBIG_LINTFLAGS:
 138       /* GNU libc does not require special actions to use LFS functions.  */
 139       string = "";
 140       string_len = 1;
 141       break;
 142
 143     default:
 144       __set_errno (EINVAL);
 145       return 0;
 146     }
 147
 148   if (len > 0 && buf != NULL)
 149     {
 150       if (string_len <= len)
 151         memcpy (buf, string, string_len);
 152       else
 153         {
 154           memcpy (buf, string, len - 1);
 155           buf[len - 1] = '\0';
 156         }
 157     }
 158   return string_len;
 159 }