sortix--sortix/libc/unistd/execl.c

/*
 * Copyright (c) 2011, 2012, 2013 Jonas 'Sortie' Termansen.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * unistd/execl.c
 * Loads a program image.
 */

#include <stdarg.h>
#include <stdlib.h>
#include <unistd.h>

int execl(const char* pathname, const char* argv0, ...)
{
	if ( !argv0 )
		return execv(pathname, (char* const*) &argv0);

	va_list args;
	va_start(args, argv0);
	size_t numargs = 1;
	while ( argv0 && va_arg(args, const char*) )
		numargs++;
	va_end(args);

	char** argv = (char**) malloc(sizeof(char*) * (numargs+1));
	if ( !argv )
		return -1;

	argv[0] = (char*) argv0;
	va_start(args, argv0);
	for ( size_t i = 1; i <= numargs; i++ )
		argv[i] = (char*) va_arg(args, const char*);
	va_end(args);
	argv[numargs] = NULL;

	int result = execv(pathname, argv);

	free(argv);

	return result;
}