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[gnulib.git]
/
lib
/
xreadlink.c
diff --git
a/lib/xreadlink.c
b/lib/xreadlink.c
index
3194d31
..
54b5e9e
100644
(file)
--- a/
lib/xreadlink.c
+++ b/
lib/xreadlink.c
@@
-1,4
+1,4
@@
-/*
exclude.c -- exclude file names
+/*
xreadlink.c -- readlink wrapper to return the link name in malloc'd storage
Copyright 2001 Free Software Foundation, Inc.
Copyright 2001 Free Software Foundation, Inc.
@@
-24,6
+24,14
@@
#endif
#include <stdio.h>
#endif
#include <stdio.h>
+#include <errno.h>
+#ifndef errno
+extern int errno;
+#endif
+
+#if HAVE_LIMITS_H
+# include <limits.h>
+#endif
#if HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#if HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
@@
-34,6
+42,13
@@
# include <unistd.h>
#endif
# include <unistd.h>
#endif
+#ifndef SIZE_MAX
+# define SIZE_MAX ((size_t) -1)
+#endif
+#ifndef SSIZE_MAX
+# define SSIZE_MAX ((ssize_t) (SIZE_MAX / 2))
+#endif
+
#include "xalloc.h"
#include "xreadlink.h"
#include "xalloc.h"
#include "xreadlink.h"
@@
-44,18
+59,17
@@
give a diagnostic and exit. */
char *
give a diagnostic and exit. */
char *
-xreadlink (char const *filename
, size_t *link_length_arg
)
+xreadlink (char const *filename)
{
/* 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;
{
/* 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;
- char *buffer = NULL;
while (1)
{
while (1)
{
-
int link_length
;
-
buffer = (char *) xrealloc (
buffer, buf_size);
- link_length = readlink (filename, buffer, buf_size);
+
char *buffer = xmalloc (buf_size)
;
+
ssize_t link_length = readlink (filename,
buffer, buf_size);
+
if (link_length < 0)
{
int saved_errno = errno;
if (link_length < 0)
{
int saved_errno = errno;
@@
-63,14
+77,16
@@
xreadlink (char const *filename, size_t *link_length_arg)
errno = saved_errno;
return NULL;
}
errno = saved_errno;
return NULL;
}
- if (link_length < buf_size)
+
+ if ((size_t) link_length < buf_size)
{
{
- *link_length_arg = link_length;
buffer[link_length] = 0;
return buffer;
}
buffer[link_length] = 0;
return buffer;
}
+
+ free (buffer);
buf_size *= 2;
buf_size *= 2;
- if (
buf_size == 0
)
+ if (
SSIZE_MAX < buf_size || (SIZE_MAX / 2 < SSIZE_MAX && buf_size == 0)
)
xalloc_die ();
}
}
xalloc_die ();
}
}