Another new function in POSIX:2008 is scandir. I cannot judge how useful it
is, but it's easy to port the implementation from glibc anyway.
2009-01-18 Bruno Haible <br...@clisp.org>
New module 'scandir'.
* lib/dirent.in.h (scandir): New declaration.
* lib/scandir.c: New file, from glibc with modifications.
* m4/scandir.m4: New file.
* modules/scandir: New file.
* m4/dirent_h.m4 (gl_DIRENT_H_DEFAULTS): Initialize GNULIB_SCANDIR,
HAVE_SCANDIR.
* modules/dirent (Makefile.am): Substitute GNULIB_SCANDIR,
HAVE_SCANDIR.
* doc/posix-functions/scandir.texi: Mention the new module and the
portability problems.
================================== lib/scandir.c ==============================
/* Copyright (C) 1992-1998, 2000, 2002, 2003, 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 <stdlib.h>
#include <string.h>
#include <errno.h>
#if _LIBC
# include <bits/libc-lock.h>
#endif
#if ! defined __builtin_expect && __GNUC__ < 3
# define __builtin_expect(expr, expected) (expr)
#endif
#undef select
#if _LIBC
# ifndef SCANDIR
# define SCANDIR scandir
# define READDIR __readdir
# define DIRENT_TYPE struct dirent
# endif
#else
# define SCANDIR scandir
# define READDIR readdir
# define DIRENT_TYPE struct dirent
# define __opendir opendir
# define __closedir closedir
# define __set_errno(val) errno = (val)
#endif
#ifndef SCANDIR_CANCEL
# define SCANDIR_CANCEL
struct scandir_cancel_struct
{
DIR *dp;
void *v;
size_t cnt;
};
# if _LIBC
static void
cancel_handler (void *arg)
{
struct scandir_cancel_struct *cp = arg;
size_t i;
void **v = cp->v;
for (i = 0; i < cp->cnt; ++i)
free (v[i]);
free (v);
(void) __closedir (cp->dp);
}
# endif
#endif
int
SCANDIR (const char *dir,
DIRENT_TYPE ***namelist,
int (*select) (const DIRENT_TYPE *),
int (*cmp) (const DIRENT_TYPE **, const DIRENT_TYPE **))
{
DIR *dp = __opendir (dir);
DIRENT_TYPE **v = NULL;
size_t vsize = 0;
struct scandir_cancel_struct c;
DIRENT_TYPE *d;
int save;
if (dp == NULL)
return -1;
save = errno;
__set_errno (0);
c.dp = dp;
c.v = NULL;
c.cnt = 0;
#if _LIBC
__libc_cleanup_push (cancel_handler, &c);
#endif
while ((d = READDIR (dp)) != NULL)
{
int use_it = select == NULL;
if (! use_it)
{
use_it = select (d);
/* The select function might have changed errno. It was
zero before and it need to be again to make the latter
tests work. */
__set_errno (0);
}
if (use_it)
{
DIRENT_TYPE *vnew;
size_t dsize;
/* Ignore errors from select or readdir */
__set_errno (0);
if (__builtin_expect (c.cnt == vsize, 0))
{
DIRENT_TYPE **new;
if (vsize == 0)
vsize = 10;
else
vsize *= 2;
new = (DIRENT_TYPE **) realloc (v, vsize * sizeof (*v));
if (new == NULL)
break;
v = new;
c.v = (void *) v;
}
dsize = &d->d_name[_D_ALLOC_NAMLEN (d)] - (char *) d;
vnew = (DIRENT_TYPE *) malloc (dsize);
if (vnew == NULL)
break;
v[c.cnt++] = (DIRENT_TYPE *) memcpy (vnew, d, dsize);
}
}
if (__builtin_expect (errno, 0) != 0)
{
save = errno;
while (c.cnt > 0)
free (v[--c.cnt]);
free (v);
c.cnt = -1;
}
else
{
/* Sort the list if we have a comparison function to sort with. */
if (cmp != NULL)
qsort (v, c.cnt, sizeof (*v), (int (*) (const void *, const void *))
cmp);
*namelist = v;
}
#if _LIBC
__libc_cleanup_pop (0);
#endif
(void) __closedir (dp);
__set_errno (save);
return c.cnt;
}
================================== m4/scandir.m4 ==============================
# scandir.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_SCANDIR],
[
AC_REQUIRE([gl_DIRENT_H_DEFAULTS])
dnl Persuade glibc and Solaris <dirent.h> to declare scandir().
AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
AC_CHECK_FUNCS([scandir])
if test $ac_cv_func_scandir = no; then
HAVE_SCANDIR=0
AC_LIBOBJ([scandir])
gl_PREREQ_SCANDIR
fi
])
# Prerequisites of lib/scandir.c.
AC_DEFUN([gl_PREREQ_SCANDIR], [:])
================================= modules/scandir =============================
Description:
scandir() function: collect entries of a directory
Files:
lib/scandir.c
m4/scandir.m4
Depends-on:
dirent
extensions
configure.ac:
gl_FUNC_SCANDIR
gl_DIRENT_MODULE_INDICATOR([scandir])
Makefile.am:
Include:
<dirent.h>
License:
LGPL
Maintainer:
all, glibc
===============================================================================
--- lib/dirent.in.h.orig 2009-01-18 12:22:31.000000000 +0100
+++ lib/dirent.in.h 2009-01-18 11:39:52.000000000 +0100
@@ -1,5 +1,5 @@
/* A GNU-like <dirent.h>.
- Copyright (C) 2006-2008 Free Software Foundation, Inc.
+ Copyright (C) 2006-2009 Free Software Foundation, Inc.
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
@@ -42,7 +42,7 @@
extern int closedir (DIR *);
#endif
-/* Declare GNU extensions. */
+/* Declare other POSIX functions. */
#if @GNULIB_DIRFD@
# if !...@have_decl_dirfd@ && !defined dirfd
@@ -58,6 +58,24 @@
dirfd (d))
#endif
+#if @GNULIB_SCANDIR@
+/* Scan the directory DIR, calling FILTER on each directory entry.
+ Entries for which FILTER returns nonzero are individually malloc'd,
+ sorted using qsort with CMP, and collected in a malloc'd array in
+ *NAMELIST. Returns the number of entries selected, or -1 on error. */
+# if !...@have_scandir@
+extern int scandir (const char *dir, struct dirent ***namelist,
+ int (*filter) (const struct dirent *),
+ int (*cmp) (const struct dirent **, const struct dirent
**));
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef scandir
+# define scandir(d,n,f,c) \
+ (GL_LINK_WARNING ("scandir is unportable - " \
+ "use gnulib module scandir for portability"), \
+ scandir (d, n, f, c))
+#endif
+
#ifdef __cplusplus
}
#endif
--- m4/dirent_h.m4.orig 2009-01-18 12:22:31.000000000 +0100
+++ m4/dirent_h.m4 2009-01-18 11:40:30.000000000 +0100
@@ -1,5 +1,5 @@
-# dirent_h.m4 serial 2
-dnl Copyright (C) 2008 Free Software Foundation, Inc.
+# dirent_h.m4 serial 3
+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,
dnl with or without modifications, as long as this notice is preserved.
@@ -33,7 +33,9 @@
[
AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) dnl for REPLACE_FCHDIR
GNULIB_DIRFD=0; AC_SUBST([GNULIB_DIRFD])
+ GNULIB_SCANDIR=0; AC_SUBST([GNULIB_SCANDIR])
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])
DIRENT_H=''; AC_SUBST([DIRENT_H])
])
--- modules/dirent.orig 2009-01-18 12:22:31.000000000 +0100
+++ modules/dirent 2009-01-18 11:41:01.000000000 +0100
@@ -25,7 +25,9 @@
-e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \
-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|@''HAVE_DECL_DIRFD''@|$(HAVE_DECL_DIRFD)|g' \
+ -e 's|@''HAVE_SCANDIR''@|$(HAVE_SCANDIR)|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/scandir.texi.orig 2009-01-18 12:22:31.000000000
+0100
+++ doc/posix-functions/scandir.texi 2009-01-18 12:11:04.000000000 +0100
@@ -4,15 +4,21 @@
POSIX specification:
@url{http://www.opengroup.org/onlinepubs/9699919799/functions/scandir.html}
-Gnulib module: ---
+Gnulib module: scandir
Portability problems fixed by Gnulib:
@itemize
+...@item
+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 fourth parameter of this function is declared as @code{int (*) (const void
*, 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.
+...@item
+The fourth parameter of this function is declared as @code{int (*) (void *,
void *)} on some platforms:
+AIX 5.1.
@end itemize
