Hi Paul,
> +
> + The PREADLINKAT function specifies how to read links.
> +
This specification is not complete: It does not explain what kind of function
pointer to pass here.
Also, it took me some time to understand how careadlinkatcwd is meant to be
used.
I'm therefore adding a few comments. Hope you can agree with it:
2011-04-09 Bruno Haible <br...@clisp.org>
careadlinkat: Clarify specification.
* lib/careadlinkat.h (careadlinkat): Clarify preadlinkat argument.
(careadlinkatcwd): Add comment.
* lib/careadlinkat.c (careadlinkat): Clarify preadlinkat argument.
--- lib/careadlinkat.h.orig Sat Apr 9 18:33:14 2011
+++ lib/careadlinkat.h Sat Apr 9 18:33:08 2011
@@ -38,7 +38,10 @@
buffer managed by ALLOC. It is the caller's responsibility to free
the returned value if it is nonnull and is not BUFFER.
- The PREADLINKAT function specifies how to read links.
+ The PREADLINKAT function specifies how to read links. It operates
+ like POSIX readlinkat()
+ <http://pubs.opengroup.org/onlinepubs/9699919799/functions/readlink.html>
+ but can assume that its first argument is the same as FD.
If successful, return the buffer address; otherwise return NULL and
set errno. */
@@ -50,8 +53,10 @@
char *, size_t));
/* Suitable values for careadlinkat's FD and PREADLINKAT arguments,
- when doing a plain readlink. */
+ when doing a plain readlink:
+ Pass FD = AT_FDCWD and PREADLINKAT = careadlinkatcwd. */
#if HAVE_READLINKAT
+/* AT_FDCWD is declared in <fcntl.h>, readlinkat in <unistd.h>. */
# define careadlinkatcwd readlinkat
#else
/* Define AT_FDCWD independently, so that the careadlinkat module does
--- lib/careadlinkat.c.orig Sat Apr 9 18:33:14 2011
+++ lib/careadlinkat.c Sat Apr 9 18:33:08 2011
@@ -65,7 +65,10 @@
the returned value if it is nonnull and is not BUFFER. A null
ALLOC stands for the standard allocator.
- The PREADLINKAT function specifies how to read links.
+ The PREADLINKAT function specifies how to read links. It operates
+ like POSIX readlinkat()
+ <http://pubs.opengroup.org/onlinepubs/9699919799/functions/readlink.html>
+ but can assume that its first argument is the same as FD.
If successful, return the buffer address; otherwise return NULL and
set errno. */
--
In memoriam Georg Elser <http://en.wikipedia.org/wiki/Georg_Elser>
