Add alphasort_r(3).

libc/Makefile

@@ -35,6 +35,7 @@ ctype/isxdigit.o \
 ctype/tolower.o \
 ctype/toupper.o \
 dirent/alphasort.o \
+dirent/alphasort_r.o \
 dirent/closedir.o \
 dirent/dclearerr.o \
 dirent/dcloseall.o \

libc/dirent/alphasort_r.cpp

@@ -0,0 +1,30 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2014.
+
+    This file is part of the Sortix C Library.
+
+    The Sortix C Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or (at your
+    option) any later version.
+
+    The Sortix C Library 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 Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
+
+    dirent/alphasort_r.cpp
+    Compare directory entries alphabetically.
+
+*******************************************************************************/
+
+#include <dirent.h>
+
+extern "C" int alphasort_r(const struct dirent** a, const struct dirent** b, void*)
+{
+	return alphasort(a, b);
+}

libc/include/dirent.h

@@ -87,6 +87,7 @@ struct dirent
 #define _D_ALLOC_NAMLEN(d) (_D_EXACT_NAMLEN(d) + 1)
 
 int alphasort(const struct dirent**, const struct dirent**);
+int alphasort_r(const struct dirent**, const struct dirent**, void*);
 int closedir(DIR* dir);
 int dirfd(DIR* dir);
 int dscandir_r(DIR*, struct dirent***,