Common daemonize function

git-svn-id: http://opensvn.csie.org/pttbbs/trunk/pttbbs@4399 63ad8ddf-47c3-0310-b6dd-a9e9d9715204

2 files changed, 91 insertions, 1 deletions

diff --git a/common/sys/Makefile b/common/sys/Makefile
index fe9fb2dc..adace886 100644
--- a/common/sys/Makefile
+++ b/common/sys/Makefile
@@ -5,7 +5,7 @@ MKPIC:=no
 SRCROOT=	../..
 .include "$(SRCROOT)/pttbbs.mk"
 
-SRCS:=	file.c lock.c log.c net.c sort.c string.c time.c crypt.c record.c vector.c
+SRCS:=	daemon.c file.c lock.c log.c net.c sort.c string.c time.c crypt.c record.c vector.c
 LIB:=	cmsys
 
 all: .depend
diff --git a/common/sys/daemon.c b/common/sys/daemon.c
new file mode 100644
index 00000000..829d0a9c
--- /dev/null
+++ b/common/sys/daemon.c
@@ -0,0 +1,90 @@
+/* $Id$ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <signal.h>
+
+#include "osdep.h"
+#include "cmsys.h"
+
+int
+daemonize(const char * pidfile, const char * logfile)
+{
+    int fd;
+    char buf[32];
+    pid_t pid;
+
+    umask(022);
+
+    if ((pid = fork()) < 0) {
+	perror("Fork failed");
+	exit(1);
+    }
+
+    if (pid > 0)
+	exit(0);
+
+    if (setsid() < 0) {
+	perror("Setsid failed");
+	exit(-1);
+    }
+
+    if ((pid = fork()) < 0) {
+	perror("Fork failed");
+	exit(1);
+    }
+
+    if (pid > 0)
+	exit(0);
+
+    if (chdir("/") < 0) {
+	perror("Can't chdir to root");
+	exit(-1);
+    }
+
+    if (pidfile) {
+	if ((fd = creat(pidfile, 0644)) >= 0) {
+	    snprintf(buf, sizeof(buf), "%d", (int)getpid());
+	    write(fd, buf, strlen(buf));
+	    close(fd);
+	} else
+	    perror("Can't open PID file");
+    }
+
+    if (logfile) {
+	if ((fd = open(logfile, O_WRONLY | O_CREAT | O_APPEND, 0644)) < 0) {
+	    perror("Can't open logfile");
+	    exit(1);
+	}
+	if (fd != 2) {
+	    dup2(fd, 2);
+	    close(fd);
+	}
+    }
+
+    fd = getdtablesize();
+    while (fd > 2)
+	close(--fd);
+
+    if ((fd = open("/dev/null", O_RDWR)) < 0) {
+	perror("Can't open /dev/null");
+	exit(1);
+    }
+
+    dup2(fd, 0);
+    dup2(fd, 1);
+    if (!logfile)
+	dup2(fd, 2);
+
+    if (fd > 2)
+	close(fd);
+
+    Signal(SIGHUP, SIG_IGN);
+    Signal(SIGCHLD, SIG_IGN);
+
+    return 0;
+}