From b9a66244f04e12509271feadf5d30d7bce2e81c9 Mon Sep 17 00:00:00 2001
From: James Lu <james@overdrivenetworks.com>
Date: Fri, 30 Mar 2018 23:23:10 -0700
Subject: [PATCH] launcher: daemonize and write PID file only after reading
 control options (-s/-R/-r)

---
 launcher.py | 69 ++++++++++++++++++++++++++++-------------------------
 1 file changed, 36 insertions(+), 33 deletions(-)

diff --git a/launcher.py b/launcher.py
index 3050bc0..d68c556 100644
--- a/launcher.py
+++ b/launcher.py
@@ -46,37 +46,6 @@ def main():
     from pylinkirc.log import log
     from pylinkirc import classes, utils, coremods
 
-    world.daemon = args.daemonize
-    if args.daemonize:
-        if args.no_pid:
-            print('ERROR: Combining --no-pid and --daemonize is not supported.')
-            sys.exit(1)
-        elif os.name != 'posix':
-            print('ERROR: Daemonization is not supported outside POSIX systems.')
-            sys.exit(1)
-        else:
-            log.info('Forking into the background.')
-            log.removeHandler(world.console_handler)
-
-            # Adapted from https://stackoverflow.com/questions/5975124/
-            if os.fork():
-                # Fork and exit the parent process.
-                os._exit(0)
-
-            os.setsid()  # Decouple from our lovely terminal
-            if os.fork():
-                # Fork again to prevent starting zombie apocalypses.
-                os._exit(0)
-    else:
-        # For foreground sessions, set the terminal window title.
-        # See https://bbs.archlinux.org/viewtopic.php?id=85567 &
-        #     https://stackoverflow.com/questions/7387276/
-        if os.name == 'nt':
-            import ctypes
-            ctypes.windll.kernel32.SetConsoleTitleW("PyLink %s" % __version__)
-        elif os.name == 'posix':
-            sys.stdout.write("\x1b]2;PyLink %s\x07" % __version__)
-
     # Write and check for an existing PID file unless specifically told not to.
     if not args.no_pid:
         pidfile = '%s.pid' % conf.confname
@@ -126,6 +95,7 @@ def main():
                         log.error("Alternatively, you can install psutil for Python 3 (pip3 install psutil), "
                                   "which will allow this launcher to detect stale PID files and ignore them.")
                 sys.exit(1)
+
         elif args.stop or args.restart or args.rehash:  # XXX: also repetitive
             # --stop and --restart should take care of stale PIDs.
             if pid:
@@ -135,12 +105,45 @@ def main():
                 log.error('Cannot stop/rehash PyLink: PID file %r does not exist.', pidfile)
             sys.exit(1)
 
-        with open(pidfile, 'w') as f:
-            f.write(str(os.getpid()))
         world._should_remove_pid = True
 
     log.info('PyLink %s starting...', __version__)
 
+    world.daemon = args.daemonize
+    if args.daemonize:
+        if args.no_pid:
+            print('ERROR: Combining --no-pid and --daemonize is not supported.')
+            sys.exit(1)
+        elif os.name != 'posix':
+            print('ERROR: Daemonization is not supported outside POSIX systems.')
+            sys.exit(1)
+        else:
+            log.info('Forking into the background.')
+            log.removeHandler(world.console_handler)
+
+            # Adapted from https://stackoverflow.com/questions/5975124/
+            if os.fork():
+                # Fork and exit the parent process.
+                os._exit(0)
+
+            os.setsid()  # Decouple from our lovely terminal
+            if os.fork():
+                # Fork again to prevent starting zombie apocalypses.
+                os._exit(0)
+    else:
+        # For foreground sessions, set the terminal window title.
+        # See https://bbs.archlinux.org/viewtopic.php?id=85567 &
+        #     https://stackoverflow.com/questions/7387276/
+        if os.name == 'nt':
+            import ctypes
+            ctypes.windll.kernel32.SetConsoleTitleW("PyLink %s" % __version__)
+        elif os.name == 'posix':
+            sys.stdout.write("\x1b]2;PyLink %s\x07" % __version__)
+
+    # Write the PID file only after forking.
+    with open(pidfile, 'w') as f:
+        f.write(str(os.getpid()))
+
     # Load configured plugins
     to_load = conf.conf['plugins']
     utils.resetModuleDirs()