1 files changed, 37 insertions, 0 deletions
diff --git a/unix_doublefork.py b/unix_doublefork.py
new file mode 100644
index 0000000..fc94a42
--- /dev/null
+++ b/unix_doublefork.py
@@ -0,0 +1,37 @@
+# -*- coding: utf-8 -*-
+"""Example of the Unix double fork for daemons."""
+import os
+import sys
+
+
+def print_process_info(name):
+    """Print information about the currently executing process."""
+    pid = os.getpid()
+    pgid = os.getpgid(pid)
+    sid = os.getsid(pid)
+    print('{} (PID:{}) (PGID:{}) (SID:{})'.format(name, pid, pgid, sid))
+
+
+# First Fork
+newpid = os.fork()
+if newpid > 0:
+    print_process_info('Parent')
+    sys.exit()
+else:
+    print_process_info('Child')
+    os.setsid()
+    newpid = os.fork()
+    # Second fork
+    if newpid == 0:
+        print_process_info('Grandchild')
+    else:
+        print_process_info('Child')
+        sys.exit()
+
+# # POP QUIZ!!!! Why won't this work
+# print_process_info('Parent')
+# os.setsid()
+# print_process_info('Parent')
+# newpid = os.fork()
+# if newpid == 0:
+#     print_process_info('Child')