From 181cec4348da40331b3e8ab365732c025ec149b2 Mon Sep 17 00:00:00 2001
From: Reinhard Tartler <siretart@tauware.de>
Date: Wed, 27 Apr 2011 19:24:15 +0200
Subject: Import upstream version 0.11.0~svn1143

---
 pid.c | 150 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 150 insertions(+)
 create mode 100644 pid.c

(limited to 'pid.c')

diff --git a/pid.c b/pid.c
new file mode 100644
index 0000000..f431b5e
--- /dev/null
+++ b/pid.c
@@ -0,0 +1,150 @@
+/* $Id: pid.c 840 2007-09-09 12:17:42Z michael $
+ * $URL: https://ssl.bulix.org/svn/lcd4linux/trunk/pid.c $
+ *
+ * PID file handling
+ *
+ * Copyright (C) 1999, 2000 Michael Reinelt <michael@reinelt.co.at>
+ *
+ * This file is part of LCD4Linux.
+ *
+ * LCD4Linux 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, or (at your option)
+ * any later version.
+ *
+ * LCD4Linux 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+/* 
+ * exported functions:
+ * 
+ * int pid_init (const char *pidfile)
+ *   returns 0 if PID file could be successfully created
+ *   returns PID of an already running process
+ *   returns -1 in case of an error
+
+ * int pid_exit (const char *pidfile)
+ *   returns 0 if PID file could be successfully deleted
+ *   otherwise returns error from unlink() call
+ *
+ */
+
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <signal.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include "debug.h"
+#include "pid.h"
+#include "qprintf.h"
+
+#ifdef WITH_DMALLOC
+#include <dmalloc.h>
+#endif
+
+
+int pid_init(const char *pidfile)
+{
+    char tmpfile[256];
+    char buffer[16];
+    int fd, len, pid;
+
+    qprintf(tmpfile, sizeof(tmpfile), "%s.%s", pidfile, "XXXXXX");
+
+    if ((fd = mkstemp(tmpfile)) == -1) {
+	error("mkstemp(%s) failed: %s", tmpfile, strerror(errno));
+	return -1;
+    }
+
+    if (fchmod(fd, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH) == -1) {
+	error("fchmod(%s) failed: %s", tmpfile, strerror(errno));
+	close(fd);
+	unlink(tmpfile);
+	return -1;
+    }
+
+    qprintf(buffer, sizeof(buffer), "%d\n", (int) getpid());
+    len = strlen(buffer);
+    if (write(fd, buffer, len) != len) {
+	error("write(%s) failed: %s", tmpfile, strerror(errno));
+	close(fd);
+	unlink(tmpfile);
+	return -1;
+    }
+    close(fd);
+
+
+    while (link(tmpfile, pidfile) == -1) {
+
+	if (errno != EEXIST) {
+	    error("link(%s, %s) failed: %s", tmpfile, pidfile, strerror(errno));
+	    unlink(tmpfile);
+	    return -1;
+	}
+
+	if ((fd = open(pidfile, O_RDONLY)) == -1) {
+	    if (errno == ENOENT)
+		continue;	/* pidfile disappared */
+	    error("open(%s) failed: %s", pidfile, strerror(errno));
+	    unlink(tmpfile);
+	    return -1;
+	}
+
+	len = read(fd, buffer, sizeof(buffer) - 1);
+	if (len < 0) {
+	    error("read(%s) failed: %s", pidfile, strerror(errno));
+	    unlink(tmpfile);
+	    return -1;
+	}
+
+	buffer[len] = '\0';
+	if (sscanf(buffer, "%d", &pid) != 1 || pid == 0) {
+	    error("scan(%s) failed.", pidfile);
+	    unlink(tmpfile);
+	    return -1;
+	}
+
+	if (pid == getpid()) {
+	    error("%s already locked by us. uh-oh...", pidfile);
+	    unlink(tmpfile);
+	    return 0;
+	}
+
+	if ((kill(pid, 0) == -1) && errno == ESRCH) {
+	    error("removing stale PID file %s", pidfile);
+	    if (unlink(pidfile) == -1 && errno != ENOENT) {
+		error("unlink(%s) failed: %s", pidfile, strerror(errno));
+		unlink(tmpfile);
+		return pid;
+	    }
+	    continue;
+	}
+	unlink(tmpfile);
+	return pid;
+    }
+
+    unlink(tmpfile);
+    return 0;
+}
+
+
+int pid_exit(const char *pidfile)
+{
+    return unlink(pidfile);
+}
-- 
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