new module alphasort

[Bruno Haible]

A companion function of scandir, also added in POSIX:2008, is alphasort.
This adds the replacement, from glibc.

2009-01-18  Bruno Haible  <address@hidden>

        New module 'alphasort'.
        * lib/dirent.in.h (alphasort): New declaration.
        * lib/alphasort.c: New file, from glibc with modifications.
        * m4/alphasort.m4: New file.
        * modules/alphasort: New file.
        * m4/dirent_h.m4 (gl_DIRENT_H_DEFAULTS): Initialize GNULIB_ALPHASORT,
        HAVE_ALPHASORT.
        * modules/dirent (Makefile.am): Substitute GNULIB_ALPHASORT,
        HAVE_ALPHASORT.
        * doc/posix-functions/alphasort.texi: Mention the new module and the
        portability problems.

=============================== lib/alphasort.c ===============================
/* Copyright (C) 1992, 1997, 1998, 2009 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   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 the
   Free Software Foundation; either version 2, or (at your option) any
   later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */

#include <config.h>

#include <dirent.h>

#include <string.h>

int
alphasort (const struct dirent **a, const struct dirent **b)
{
  return strcoll ((*a)->d_name, (*b)->d_name);
}
=============================== m4/alphasort.m4 ===============================
# alphasort.m4 serial 1
dnl Copyright (C) 2009 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.

AC_DEFUN([gl_FUNC_ALPHASORT],
[
  AC_REQUIRE([gl_DIRENT_H_DEFAULTS])

  dnl Persuade glibc and Solaris <dirent.h> to declare alphasort().
  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])

  AC_CHECK_FUNCS([alphasort])
  if test $ac_cv_func_alphasort = no; then
    HAVE_ALPHASORT=0
    AC_LIBOBJ([alphasort])
    gl_PREREQ_ALPHASORT
  fi
])

# Prerequisites of lib/alphasort.c.
AC_DEFUN([gl_PREREQ_ALPHASORT], [:])
============================== modules/alphasort ==============================
Description:
alphasort() function: compare entries of a directory alphabetically

Files:
lib/alphasort.c
m4/alphasort.m4

Depends-on:
dirent
extensions

configure.ac:
gl_FUNC_ALPHASORT
gl_DIRENT_MODULE_INDICATOR([alphasort])

Makefile.am:

Include:
<dirent.h>

License:
LGPL

Maintainer:
all, glibc

===============================================================================
--- lib/dirent.in.h.orig        2009-01-18 12:36:48.000000000 +0100
+++ lib/dirent.in.h     2009-01-18 12:31:04.000000000 +0100
@@ -76,6 +76,19 @@
      scandir (d, n, f, c))
 #endif
 
+#if @GNULIB_ALPHASORT@
+/* Compare two 'struct dirent' entries alphabetically.  */
+# if address@hidden@
+extern int alphasort (const struct dirent **, const struct dirent **);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef alphasort
+# define alphasort(a,b) \
+    (GL_LINK_WARNING ("alphasort is unportable - " \
+                      "use gnulib module alphasort for portability"), \
+     alphasort (a, b))
+#endif
+
 #ifdef __cplusplus
 }
 #endif
--- m4/dirent_h.m4.orig 2009-01-18 12:36:48.000000000 +0100
+++ m4/dirent_h.m4      2009-01-18 12:32:18.000000000 +0100
@@ -1,4 +1,4 @@
-# dirent_h.m4 serial 3
+# dirent_h.m4 serial 4
 dnl Copyright (C) 2008-2009 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -32,10 +32,12 @@
 AC_DEFUN([gl_DIRENT_H_DEFAULTS],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) dnl for REPLACE_FCHDIR
-  GNULIB_DIRFD=0;    AC_SUBST([GNULIB_DIRFD])
-  GNULIB_SCANDIR=0;  AC_SUBST([GNULIB_SCANDIR])
+  GNULIB_DIRFD=0;     AC_SUBST([GNULIB_DIRFD])
+  GNULIB_SCANDIR=0;   AC_SUBST([GNULIB_SCANDIR])
+  GNULIB_ALPHASORT=0; AC_SUBST([GNULIB_ALPHASORT])
   dnl Assume proper GNU behavior unless another module says otherwise.
   HAVE_DECL_DIRFD=1; AC_SUBST([HAVE_DECL_DIRFD])
   HAVE_SCANDIR=1;    AC_SUBST([HAVE_SCANDIR])
+  HAVE_ALPHASORT=1;  AC_SUBST([HAVE_ALPHASORT])
   DIRENT_H='';       AC_SUBST([DIRENT_H])
 ])
--- modules/dirent.orig 2009-01-18 12:36:48.000000000 +0100
+++ modules/dirent      2009-01-18 12:31:39.000000000 +0100
@@ -26,8 +26,10 @@
              -e 's|@''NEXT_DIRENT_H''@|$(NEXT_DIRENT_H)|g' \
              -e 's|@''GNULIB_DIRFD''@|$(GNULIB_DIRFD)|g' \
              -e 's|@''GNULIB_SCANDIR''@|$(GNULIB_SCANDIR)|g' \
+             -e 's|@''GNULIB_ALPHASORT''@|$(GNULIB_ALPHASORT)|g' \
              -e 's|@''HAVE_DECL_DIRFD''@|$(HAVE_DECL_DIRFD)|g' \
              -e 's|@''HAVE_SCANDIR''@|$(HAVE_SCANDIR)|g' \
+             -e 's|@''HAVE_ALPHASORT''@|$(HAVE_ALPHASORT)|g' \
              -e 's|@''REPLACE_FCHDIR''@|$(REPLACE_FCHDIR)|g' \
              -e '/definition of GL_LINK_WARNING/r $(LINK_WARNING_H)' \
              < $(srcdir)/dirent.in.h; \
--- doc/posix-functions/alphasort.texi.orig     2009-01-18 12:36:48.000000000 
+0100
+++ doc/posix-functions/alphasort.texi  2009-01-18 12:14:38.000000000 +0100
@@ -4,15 +4,21 @@
 
 POSIX specification: 
@url{http://www.opengroup.org/onlinepubs/9699919799/functions/alphasort.html}
 
-Gnulib module: ---
+Gnulib module: alphasort
 
 Portability problems fixed by Gnulib:
 @itemize
address@hidden
+This function is missing on some platforms:
+Solaris 9, mingw, BeOS.
 @end itemize
 
 Portability problems not fixed by Gnulib:
 @itemize
 @item
-This function is missing on some platforms:
-Solaris 9, mingw, BeOS.
+The parameters of this function are declared as @code{const void *} on some 
platforms:
+glibc 2.3.6, MacOS X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Interix 3.5.
address@hidden
+The parameters of this function are declared as @code{void *} on some 
platforms:
+AIX 5.1.
 @end itemize