1 /* Error-checking, allocating wrapper for readlink.
2    Copyright (C) 2017-2022 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 <scratch_buffer.h>
20 #include <support/check.h>
21 #include <support/support.h>
22 #include <xunistd.h>
23 
24 char *
xreadlink(const char * path)25 xreadlink (const char *path)
26 {
27   struct scratch_buffer buf;
28   scratch_buffer_init (&buf);
29 
30   while (true)
31     {
32       ssize_t count = readlink (path, buf.data, buf.length);
33       if (count < 0)
34         FAIL_EXIT1 ("readlink (\"%s\"): %m", path);
35       if (count < buf.length)
36         {
37           char *result = xstrndup (buf.data, count);
38           scratch_buffer_free (&buf);
39           return result;
40         }
41       if (!scratch_buffer_grow (&buf))
42         FAIL_EXIT1 ("scratch_buffer_grow in xreadlink");
43     }
44 }
45