libc/unistd/confstr.c

   1 /* Copyright (C) 1991, 1996, 1997, 2000-2002, 2003, 2004
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <stddef.h>
  20 #include <errno.h>
  21 #include <unistd.h>
  22 #include <string.h>
  23
  24
  25 #define CS_PATH "/bin:/usr/bin"
  26
  27 /* If BUF is not NULL and LEN > 0, fill in at most LEN - 1 bytes
  28    of BUF with the value corresponding to NAME and zero-terminate BUF.
  29    Return the number of bytes required to hold NAME's entire value.  */
  30 size_t confstr (int name, char *buf, size_t len)
  31 {
  32   const char *string;
  33   size_t string_len;
  34
  35   switch (name)
  36     {
  37     case _CS_PATH:
  38       {
  39         static const char cs_path[] = CS_PATH;
  40         string = cs_path;
  41         string_len = sizeof (cs_path);
  42       }
  43       break;
  44 #ifdef __UCLIBC_HAS_THREADS__
  45     case _CS_GNU_LIBPTHREAD_VERSION:
  46 # if defined __UCLIBC_HAS_LINUXTHREADS__
  47       string = "linuxthreads-0.01";
  48       string_len = sizeof("linuxthreads-x.xx");
  49 # elif defined __UCLIBC_HAS_THREADS_NATIVE__
  50 #  define __NPTL_VERSION ("NPTL " \
  51                 __stringify(__UCLIBC_MAJOR__) "." \
  52                 __stringify(__UCLIBC_MINOR__) "." \
  53                 __stringify(__UCLIBC_SUBLEVEL__))
  54       string = __NPTL_VERSION;
  55       string_len = sizeof(__NPTL_VERSION);
  56 # else
  57 #  error unable to determine thread impl
  58 # endif
  59       break;
  60 #endif
  61     default:
  62       __set_errno (EINVAL);
  63       return 0;
  64     }
  65
  66   if (len > 0 && buf != NULL)
  67     {
  68       if (string_len <= len)
  69         memcpy (buf, string, string_len);
  70       else
  71         {
  72           memcpy (buf, string, len - 1);
  73           buf[len - 1] = '\0';
  74         }
  75     }
  76   return string_len;
  77 }