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/* exclude.c -- exclude file names
Copyright 2001 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING.
If not, write to the Free Software Foundation,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/* Written by Jim Meyering <jim@meyering.net> */
#if HAVE_CONFIG_H
# include <config.h>
#endif
#include <stdio.h>
#if HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#if HAVE_STDLIB_H
# include <stdlib.h>
#endif
#if HAVE_UNISTD_H
# include <unistd.h>
#endif
#include "xalloc.h"
#include "xreadlink.h"
/* Call readlink to get the symbolic link value of FILENAME.
Return a pointer to that NUL-terminated string in malloc'd storage.
If readlink fails, return NULL (use errno to diagnose).
If realloc fails, or if the link value is longer than SIZE_MAX :-),
give a diagnostic and exit. */
char *
xreadlink (char const *filename, size_t *link_length_arg)
{
size_t buf_size = 128; /* must be a power of 2 */
char *buffer = NULL;
while (1)
{
int link_length;
buffer = (char *) xrealloc (buffer, buf_size);
link_length = readlink (filename, buffer, buf_size);
if (link_length < 0)
{
free (buffer);
return NULL;
}
if (link_length < buf_size)
{
*link_length_arg = link_length;
buffer[link_length] = 0;
return buffer;
}
buf_size *= 2;
if (buf_size == 0)
xalloc_die ();
}
}
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