regex_internal.h: define __attribute_warn_unused_result__

[gnulib.git] / doc / posix-functions / readlinkat.texi

diff --git a/doc/posix-functions/readlinkat.texi b/doc/posix-functions/readlinkat.texi
index b64b443..4cef743 100644 (file)
--- a/doc/posix-functions/readlinkat.texi
+++ b/doc/posix-functions/readlinkat.texi
@@ -12,6 +12,7 @@ Portability problems fixed by Gnulib:
 This function is missing on some platforms:
 glibc 2.3.6, MacOS X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, AIX
 5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 10, Cygwin 1.5.x, mingw, Interix 3.5, BeOS.
+But the replacement function is not safe to be used in libraries and is not multithread-safe.
 @end itemize
 
 Portability problems not fixed by Gnulib:
@@ -28,4 +29,12 @@ directories, Cygwin sets @code{errno} to @code{ENOENT} or @code{EIO} instead of
 When @code{readlink} is called on a file that is not a symbolic link:
 Irix may set @code{errno} to @code{ENXIO} instead of @code{EINVAL}.  Cygwin
 may set errno to @code{EACCES} instead of @code{EINVAL}.
+@item
+Symlink contents do not always have a trailing null byte, and there is
+no indication if symlink contents were truncated if the return value
+matches the length.  Furthermore, AIX 5.1 and HP-UX 11 set
+@code{errno} to @code{ERANGE} rather than returning truncated
+contents, and Linux sets @code{errno} to @code{EINVAL} if the
+requested length is zero.  Use the gnulib module areadlink for
+improved ability to read symlink contents.
 @end itemize