diff src/daemon.c @ 0:0aa1171aebd2 stable-1-0-0

initial version
author Carl Byington <carl@five-ten-sg.com>
date Wed, 15 May 2013 13:15:59 -0700
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/daemon.c	Wed May 15 13:15:59 2013 -0700
@@ -0,0 +1,61 @@
+/*Add by Sergey Shapovalov */
+#include <unistd.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <errno.h>
+
+/* closeall() -- close all FDs >= a specified value */
+
+void closeall(int fd)
+{
+	int fdlimit = sysconf(_SC_OPEN_MAX);
+
+	while (fd < fdlimit)
+	  close(fd++);
+}
+
+/* daemon() - detach process from user and disappear into the background
+ * returns -1 on failure, but you can't do much except exit in that case
+ * since we may already have forked. This is based on the BSD version,
+ * so the caller is responsible for things like the umask, etc.
+ */
+
+/* believed to work on all Posix systems */
+
+int daemon(int nochdir, int noclose)
+{
+	switch (fork())
+	{
+		case 0:  break;
+		case -1: return -1;
+		default: _exit(0);			/* exit the original process */
+	}
+
+	if (setsid() < 0)				/* shoudn't fail */
+	  return -1;
+
+	/* dyke out this switch if you want to acquire a control tty in */
+	/* the future -- not normally advisable for daemons */
+
+	switch (fork())
+	{
+		case 0:  break;
+		case -1: return -1;
+		default: _exit(0);
+	}
+
+	if (!nochdir)
+	  chdir("/");
+
+	if (!noclose)
+	{
+		closeall(0);
+		open("/dev/null",O_RDWR);
+		dup(0); dup(0);
+	}
+
+	return 0;
+}