Add execlpe(3).

libc/Makefile

@@ -528,6 +528,7 @@ unistd/dup.o \
 unistd/environ.o \
 unistd/execle.o \
 unistd/execl.o \
+unistd/execlpe.o \
 unistd/execlp.o \
 unistd/execve.o \
 unistd/execv.o \

libc/unistd/execlpe.cpp

@@ -0,0 +1,59 @@
+/*******************************************************************************
+
+    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/>.
+
+    unistd/execlpe.cpp
+    Loads a program image.
+
+*******************************************************************************/
+
+#include <stdarg.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+extern "C" int execlpe(const char* filename, const char* argv0, ...)
+{
+	va_list args;
+	va_start(args, argv0);
+	size_t numargs = 0;
+	if ( argv0 )
+	{
+		numargs++;
+		while ( va_arg(args, const char*) )
+			numargs++;
+	}
+	(void) va_arg(args, char* const*) /* envp */;
+	va_end(args);
+
+	char** argv = (char**) malloc(sizeof(char*) * (numargs + 1));
+	if ( !argv )
+		return -1;
+
+	va_start(args, argv0);
+	argv[0] = (char*) argv0;
+	for ( size_t i = 1; i <= numargs; i++ )
+		argv[i] = (char*) va_arg(args, const char*);
+	char* const* envp = va_arg(args, char* const*);
+	va_end(args);
+
+	int result = execvpe(filename, argv, envp);
+
+	free(argv);
+
+	return result;
+}