Use replacement library functions to daemonize, rather than #ifdef hell

2 files changed, 62 insertions, 0 deletions

diff --git a/lib/daemon.c b/lib/daemon.c
new file mode 100644
index 0000000..c3106b5
--- /dev/null
+++ b/lib/daemon.c
@@ -0,0 +1,37 @@
+/*
+ * daemon.c - "daemonize" a process
+ */
+
+#include "config.h"
+
+int daemon(int nochdir, int noclose)
+{
+	int nullfd;
+	pid_t f;
+	
+	if (!nochdir) {
+		if (chdir("/"))
+			return -1;
+	}
+
+	if (!noclose) {
+		if ((nullfd = open("/dev/null", O_RDWR)) < 0 ||
+		    dup2(nullfd, 0) < 0 ||
+		    dup2(nullfd, 1) < 0 ||
+		    dup2(nullfd, 2) < 0)
+			return -1;
+		close(nullfd);
+	}
+
+	f = fork();
+	if (f < 0)
+		return -1;
+	else if (f > 0)
+		_exit(0);
+
+#ifdef HAVE_SETSID
+	return setsid();
+#else
+	return 0;
+#endif
+}
diff --git a/lib/dup2.c b/lib/dup2.c
new file mode 100644
index 0000000..bdf3325
--- /dev/null
+++ b/lib/dup2.c
@@ -0,0 +1,25 @@
+/*
+ * dup2.c
+ *
+ * Ersatz dup2() for really ancient systems
+ */
+
+#include "config.h"
+
+int dup2(int oldfd, int newfd)
+{
+  int rv, nfd;
+
+  close(newfd);
+
+  nfd = rv = dup(oldfd);
+
+  if (rv >= 0 && rv != newfd) {
+    rv = dup2(oldfd, newfd);
+    close(nfd);
+  }
+
+  return rv;
+}
+
+