I did most of this weeks ago and just noticed I never checked it in.
Ok with you, Bruno?
Rewrite xreadlink as a trivial mreadlink wrapper.
* lib/xreadlink.c (xreadlink): Rewrite as a simple mreadlink wrapper.
* modules/xreadlink: Adjust dependencies.
Index: lib/xreadlink.c
===================================================================
RCS file: /cvsroot/gnulib/gnulib/lib/xreadlink.c,v
retrieving revision 1.26
diff -u -p -r1.26 xreadlink.c
--- lib/xreadlink.c 3 Mar 2007 19:20:41 -0000 1.26
+++ lib/xreadlink.c 23 Aug 2007 11:35:05 -0000
@@ -25,7 +25,6 @@
/* Specification. */
#include "xreadlink.h"
-#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <limits.h>
@@ -40,92 +39,18 @@
# define SSIZE_MAX ((ssize_t) (SIZE_MAX / 2))
#endif
-#ifdef NO_XMALLOC
-# define xmalloc malloc
-#else
-# include "xalloc.h"
-#endif
+#include "mreadlink.h"
+#include "xalloc.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 (caller may use errno to diagnose).
- If realloc fails, or if the link value is longer than SIZE_MAX :-),
- give a diagnostic and exit. */
+/* Call mreadlink to get the symbolic link value of FILENAME in malloc'd
+ storage. If mreadlink fails, call xalloc_die. Otherwise, return
+ the malloc'd string. */
char *
xreadlink (char const *filename)
{
- /* The initial buffer size for the link value. A power of 2
- detects arithmetic overflow earlier, but is not required. */
-#define INITIAL_BUF_SIZE 1024
-
- /* Allocate the initial buffer on the stack. This way, in the common
- case of a symlink of small size, we get away with a single small malloc()
- instead of a big malloc() followed by a shrinking realloc(). */
- char initial_buf[INITIAL_BUF_SIZE];
-
- char *buffer = initial_buf;
- size_t buf_size = sizeof (initial_buf);
-
- while (1)
- {
- /* Attempt to read the link into the current buffer. */
- ssize_t link_length = readlink (filename, buffer, buf_size);
-
- /* On AIX 5L v5.3 and HP-UX 11i v2 04/09, readlink returns -1
- with errno == ERANGE if the buffer is too small. */
- if (link_length < 0 && errno != ERANGE)
- {
- if (buffer != initial_buf)
- {
- int saved_errno = errno;
- free (buffer);
- errno = saved_errno;
- }
- return NULL;
- }
-
- if ((size_t) link_length < buf_size)
- {
- buffer[link_length++] = '\0';
-
- /* Return it in a chunk of memory as small as possible. */
- if (buffer == initial_buf)
- {
- buffer = (char *) xmalloc (link_length);
-#ifdef NO_XMALLOC
- if (buffer == NULL)
- return NULL;
-#endif
- memcpy (buffer, initial_buf, link_length);
- }
- else
- {
- /* Shrink buffer before returning it. */
- if ((size_t) link_length < buf_size)
- {
- char *smaller_buffer = (char *) realloc (buffer, link_length);
-
- if (smaller_buffer != NULL)
- buffer = smaller_buffer;
- }
- }
- return buffer;
- }
-
- if (buffer != initial_buf)
- free (buffer);
- buf_size *= 2;
- if (SSIZE_MAX < buf_size || (SIZE_MAX / 2 < SSIZE_MAX && buf_size == 0))
-#ifdef NO_XMALLOC
- return NULL;
-#else
- xalloc_die ();
-#endif
- buffer = (char *) xmalloc (buf_size);
-#ifdef NO_XMALLOC
- if (buffer == NULL)
- return NULL;
-#endif
- }
+ char *p = mreadlink (filename);
+ if (p == NULL)
+ xalloc_die ();
+ return p;
}
Index: modules/xreadlink
===================================================================
RCS file: /cvsroot/gnulib/gnulib/modules/xreadlink,v
retrieving revision 1.15
diff -u -p -r1.15 xreadlink
--- modules/xreadlink 3 Mar 2007 19:20:41 -0000 1.15
+++ modules/xreadlink 23 Aug 2007 11:35:05 -0000
@@ -1,15 +1,13 @@
Description:
-Reading symbolic links without size limitation.
+Read symbolic links without size limitation.
Files:
lib/xreadlink.h
lib/xreadlink.c
Depends-on:
-readlink
-ssize_t
-unistd
-xalloc
+mreadlink
+xalloc-die
configure.ac:
