posix/confstr.c

   1 /* Copyright (C) 1991,96,97,2000-2003, 2004 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 #include "../version.h"
  25
  26 /* If BUF is not NULL and LEN > 0, fill in at most LEN - 1 bytes
  27    of BUF with the value corresponding to NAME and zero-terminate BUF.
  28    Return the number of bytes required to hold NAME's entire value.  */
  29 size_t
  30 confstr (name, buf, len)
  31      int name;
  32      char *buf;
  33      size_t len;
  34 {
  35   const char *string = "";
  36   size_t string_len = 1;
  37
  38   switch (name)
  39     {
  40     case _CS_PATH:
  41       {
  42         static const char cs_path[] = CS_PATH;
  43         string = cs_path;
  44         string_len = sizeof (cs_path);
  45       }
  46       break;
  47
  48     case _CS_V6_WIDTH_RESTRICTED_ENVS:
  49       /* We have to return a newline-separated list of named of
  50          programming environements in which the widths of blksize_t,
  51          cc_t, mode_t, nfds_t, pid_t, ptrdiff_t, size_t, speed_t,
  52          ssize_t, suseconds_t, tcflag_t, useconds_t, wchar_t, and
  53          wint_t types are no greater than the width of type long.
  54
  55          Currently this means all environment which the system allows.  */
  56       {
  57         static const char restenvs[] =
  58 #if _POSIX_V6_ILP32_OFF32 > 0
  59         "_POSIX_V6_ILP32_OFF32"
  60 #endif
  61 #if _POSIX_V6_ILP32_OFFBIG > 0
  62 # if _POSIX_V6_ILP32_OFF32 > 0
  63         "\n"
  64 # endif
  65         "_POSIX_V6_ILP32_OFFBIG"
  66 #endif
  67 #if _POSIX_V6_LP64_OFF64 > 0
  68 # if _POSIX_V6_ILP32_OFF32 > 0 || _POSIX_V6_ILP32_OFFBIG > 0
  69         "\n"
  70 # endif
  71         "_POSIX_V6_LP64_OFF64"
  72 #endif
  73 #if _POSIX_V6_LPBIG_OFFBIG > 0
  74 # if _POSIX_V6_ILP32_OFF32 > 0 || _POSIX_V6_ILP32_OFFBIG > 0 \
  75      || _POSIX_V6_LP64_OFF64 > 0
  76         "\n"
  77 # endif
  78         "_POSIX_V6_LPBIG_OFFBIG"
  79 #endif
  80           ;
  81         string = restenvs;
  82         string_len = sizeof (restenvs);
  83       }
  84       break;
  85
  86     case _CS_XBS5_ILP32_OFFBIG_CFLAGS:
  87     case _CS_POSIX_V6_ILP32_OFFBIG_CFLAGS:
  88     case _CS_LFS_CFLAGS:
  89     case _CS_LFS_LINTFLAGS:
  90 #if _XBS5_LP64_OFF64 == -1 && _XBS5_LPBIG_OFFBIG == -1 && _XBS5_ILP32_OFFBIG == 1
  91       /* Signal that we want the new ABI.  */
  92       {
  93         static const char file_offset[]
  94           = "-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64";
  95         string = file_offset;
  96         string_len = sizeof (file_offset);
  97       }
  98       break;
  99 #endif
 100       /* FALLTHROUGH */
 101
 102     case _CS_LFS_LDFLAGS:
 103     case _CS_LFS_LIBS:
 104       /* No special libraries or linker flags needed.  */
 105       break;
 106
 107     case _CS_LFS64_CFLAGS:
 108     case _CS_LFS64_LINTFLAGS:
 109       if (sizeof (off_t) != sizeof (off64_t))
 110         {
 111           static const char lf64_source[] = "-D_LARGEFILE64_SOURCE";
 112           string = lf64_source;
 113           string_len = sizeof (lf64_source);
 114         }
 115       break;
 116
 117     case _CS_LFS64_LDFLAGS:
 118     case _CS_LFS64_LIBS:
 119       /* No special libraries or linker flags needed.  */
 120       break;
 121
 122     case _CS_XBS5_ILP32_OFF32_CFLAGS:
 123     case _CS_XBS5_ILP32_OFF32_LDFLAGS:
 124     case _CS_XBS5_ILP32_OFF32_LIBS:
 125     case _CS_XBS5_ILP32_OFF32_LINTFLAGS:
 126     case _CS_XBS5_ILP32_OFFBIG_LDFLAGS:
 127     case _CS_XBS5_ILP32_OFFBIG_LIBS:
 128     case _CS_XBS5_ILP32_OFFBIG_LINTFLAGS:
 129     case _CS_XBS5_LP64_OFF64_CFLAGS:
 130     case _CS_XBS5_LP64_OFF64_LDFLAGS:
 131     case _CS_XBS5_LP64_OFF64_LIBS:
 132     case _CS_XBS5_LP64_OFF64_LINTFLAGS:
 133     case _CS_XBS5_LPBIG_OFFBIG_CFLAGS:
 134     case _CS_XBS5_LPBIG_OFFBIG_LDFLAGS:
 135     case _CS_XBS5_LPBIG_OFFBIG_LIBS:
 136     case _CS_XBS5_LPBIG_OFFBIG_LINTFLAGS:
 137
 138     case _CS_POSIX_V6_ILP32_OFF32_CFLAGS:
 139     case _CS_POSIX_V6_ILP32_OFF32_LDFLAGS:
 140     case _CS_POSIX_V6_ILP32_OFF32_LIBS:
 141     case _CS_POSIX_V6_ILP32_OFF32_LINTFLAGS:
 142     case _CS_POSIX_V6_ILP32_OFFBIG_LDFLAGS:
 143     case _CS_POSIX_V6_ILP32_OFFBIG_LIBS:
 144     case _CS_POSIX_V6_ILP32_OFFBIG_LINTFLAGS:
 145     case _CS_POSIX_V6_LP64_OFF64_CFLAGS:
 146     case _CS_POSIX_V6_LP64_OFF64_LDFLAGS:
 147     case _CS_POSIX_V6_LP64_OFF64_LIBS:
 148     case _CS_POSIX_V6_LP64_OFF64_LINTFLAGS:
 149     case _CS_POSIX_V6_LPBIG_OFFBIG_CFLAGS:
 150     case _CS_POSIX_V6_LPBIG_OFFBIG_LDFLAGS:
 151     case _CS_POSIX_V6_LPBIG_OFFBIG_LIBS:
 152     case _CS_POSIX_V6_LPBIG_OFFBIG_LINTFLAGS:
 153       /* GNU libc does not require special actions to use LFS functions.  */
 154       break;
 155
 156     case _CS_GNU_LIBC_VERSION:
 157       string = "glibc " VERSION;
 158       string_len = sizeof ("glibc " VERSION);
 159       break;
 160
 161     case _CS_GNU_LIBPTHREAD_VERSION:
 162 #ifdef LIBPTHREAD_VERSION
 163       string = LIBPTHREAD_VERSION;
 164       string_len = sizeof LIBPTHREAD_VERSION;
 165       break;
 166 #else
 167       /* No thread library.  */
 168       __set_errno (EINVAL);
 169       return 0;
 170 #endif
 171
 172     default:
 173       __set_errno (EINVAL);
 174       return 0;
 175     }
 176
 177   if (len > 0 && buf != NULL)
 178     {
 179       if (string_len <= len)
 180         memcpy (buf, string, string_len);
 181       else
 182         {
 183           memcpy (buf, string, len - 1);
 184           buf[len - 1] = '\0';
 185         }
 186     }
 187   return string_len;
 188 }
 189 libc_hidden_def (confstr)