minit, a Minimal init system.

init/pidfilehack.c

@@ -0,0 +1,78 @@
+/*
+ *  minit version 0.9.1 by Felix von Leitner
+ *  ported to busybox by Glenn McGrath <bug1@optushome.com.au>
+ *
+ *  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 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, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <unistd.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <sys/fcntl.h>
+
+#include "busybox.h"
+/* purpose: argv[1] is the full path to a PID file,
+ *          argv+2 is the daemon to run.
+ * the daemon is expected to fork in the background and write its PID in
+ * the pid file.
+ */
+
+extern int pidfilehack_main(int argc, char **argv)
+{
+	int count = 0;
+
+	if (argc < 3) {
+		bb_show_usage();
+
+	}
+	if (unlink(argv[2]) && (errno != ENOENT)) {
+		bb_perror_msg("could not remove pid file");
+	}
+	switch (fork()) {
+	case -1:
+		bb_perror_msg("could not fork");
+		return 2;
+	case 0:	/* child */
+		execv(argv[3], argv + 3);
+		bb_perror_msg("execvp failed");
+		return 3;
+	}
+	do {
+		int fd = open(argv[2], O_RDONLY);
+
+		if (fd >= 0) {
+			static char buf[100] = "-P";
+			int len = read(fd, buf + 2, 100);
+
+			close(fd);
+			if (len > 0) {
+				char *_argv[] = { "msvc", 0, 0, 0 };
+				if (buf[len + 1] == '\n') {
+					buf[len + 1] = 0;
+				} else {
+					buf[len + 2] = 0;
+				}
+				_argv[1] = buf;
+				_argv[2] = argv[1];
+				execvp(_argv[0], _argv);
+				bb_perror_msg("execvp failed");
+				return 0;
+			}
+		}
+		sleep(1);
+	} while (++count < 30);
+
+	return(0);
+}