/* Copyright (C) 2014 Luke Shumaker <lukeshu@sbcglobal.net>
 *
 * 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 3 of the License, 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, see <http://www.gnu.org/licenses/>.
 */

#define _GNU_SOURCE /* for unsetenv(3) */
#include <alloca.h> /* for alloca(3) */
#include <errno.h> /* for errno */
#include <error.h> /* for error(3) */
#include <pwd.h> /* for getpwuid(3) */
#include <stdio.h> /* for printf(3) */
#include <stdlib.h> /* for unsetenv(3) */
#include <string.h> /* for strlen(3), strcpy(3) */
#include <unistd.h> /* for dup2(3), geteuid(3), execl(3) */

void
usage(const char *cmd)
{
	printf("Usage: %s PACKAGE\n", cmd);
	printf("This command should be run from the git directory of the package source.");
}

int
main(int argc, char **argv)
{
	if (argc != 2) {
		dup2(2,1);
		usage(argv[0]);
		return 1;
	}

	const char *home = getpwuid(geteuid())->pw_dir;
	const char *script_suffix = "/bin/autobuild.sh";
	char *script = alloca(strlen(home)+strlen(script_suffix));
	strcpy(script, home);
	strcpy(&(script[strlen(home)]), script_suffix);

	unsetenv("IFS");
	unsetenv("PATH");
	unsetenv("LD_PRELOAD");
	unsetenv("BASH_ENV");

	execl(script, script, argv[1], NULL);
	error(127, errno, "%s", script);
}