/* xreadlink.c -- readlink wrapper to return the link name in malloc'd storage
- Copyright (C) 2001, 2003 Free Software Foundation, Inc.
+ Copyright (C) 2001, 2003, 2004 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
# include <config.h>
#endif
+#include "xreadlink.h"
+
#include <stdio.h>
#include <errno.h>
#ifndef errno
#endif
#include "xalloc.h"
-#include "xreadlink.h"
/* Call readlink to get the symbolic link value of FILENAME.
+ SIZE is a hint as to how long the link is expected to be;
+ typically it is taken from st_size. It need not be correct.
Return a pointer to that NUL-terminated string in malloc'd storage.
If readlink fails, return NULL (caller may use errno to diagnose).
If malloc fails, or if the link value is longer than SSIZE_MAX :-),
give a diagnostic and exit. */
char *
-xreadlink (char const *filename)
+xreadlink (char const *filename, size_t size)
{
/* The initial buffer size for the link value. A power of 2
detects arithmetic overflow earlier, but is not required. */
- size_t buf_size = 128;
+ size_t buf_size = size + 1;
while (1)
{
free (buffer);
buf_size *= 2;
- if (SSIZE_MAX < buf_size || (SIZE_MAX / 2 < SSIZE_MAX && buf_size == 0))
+ if (! (0 < buf_size && buf_size <= SSIZE_MAX))
xalloc_die ();
}
}