1  /* Error-checking wrapper for sysconf.
       2     Copyright (C) 2017-2023 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     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <errno.h>
      20  #include <support/check.h>
      21  #include <support/xunistd.h>
      22  
      23  long
      24  xsysconf (int name)
      25  {
      26    /* Detect errors by a changed errno value, in case -1 is a valid
      27       value.  Make sure that the caller does not see the zero value for
      28       errno.  */
      29    int old_errno = errno;
      30    errno = 0;
      31    long result = sysconf (name);
      32    if (result == -1 && errno != 0)
      33      FAIL_EXIT1 ("sysconf (%d): %m", name);
      34    errno = old_errno;
      35    return result;
      36  }