1  /* Open an nss_files database file.
       2     Copyright (C) 2020-2023 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 <nss_files.h>
      20  
      21  #include <errno.h>
      22  #include <stdio_ext.h>
      23  
      24  FILE *
      25  __nss_files_fopen (const char *path)
      26  {
      27    FILE *fp = fopen (path, "rce");
      28    if (fp == NULL)
      29      return NULL;
      30  
      31    /* The stream is not shared across threads.  */
      32    __fsetlocking (fp, FSETLOCKING_BYCALLER);
      33  
      34    /* This tells libio that the file is seekable, and that fp->_offset
      35       is correct, ensuring that __ftello64 is efficient (bug 26257).  */
      36    if (__fseeko64 (fp, 0, SEEK_SET) < 0)
      37      {
      38        /* nss_files requires seekable files, to deal with repeated
      39           reads of the same line after reporting ERANGE.  */
      40        fclose (fp);
      41        __set_errno (ESPIPE);
      42        return NULL;
      43      }
      44  
      45    return fp;
      46  }
      47  libc_hidden_def (__nss_files_fopen)