support/support_write_file_string.c

   1 /* Write a string to a file.
   2    Copyright (C) 2017-2018 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 <fcntl.h>
  20 #include <string.h>
  21 #include <support/check.h>
  22 #include <support/xunistd.h>
  23
  24 void
  25 support_write_file_string (const char *path, const char *contents)
  26 {
  27   int fd = xopen (path, O_CREAT | O_TRUNC | O_WRONLY, 0666);
  28   const char *end = contents + strlen (contents);
  29   for (const char *p = contents; p < end; )
  30     {
  31       ssize_t ret = write (fd, p, end - p);
  32       if (ret < 0)
  33         FAIL_EXIT1 ("cannot write to \"%s\": %m", path);
  34       if (ret == 0)
  35         FAIL_EXIT1 ("zero-length write to \"%s\"", path);
  36       p += ret;
  37     }
  38   xclose (fd);
  39 }