Terminate blockers that are already running.

blocker.py

@@ -7,7 +7,8 @@ import subprocess
 import sys
 import time
 
-
+BLOCKER = "blocker.py"
+BLOCKER_CONFIG_DIR = "/home/{}/.config/focusfriend"
 BLOCKED_BROWSER_WORDS = ["mogelpower", "DER SPIEGEL", "nitter"]
 
 
@@ -63,7 +64,44 @@ def notify(message):
     p = subprocess.run(CMD, env=env)
 
 
-def main():
+def get_config_dir() -> str:
+    user = os.environ["SUDO_USER"]
+    config_dir = BLOCKER_CONFIG_DIR.format(user)
+    assert(os.path.isdir(config_dir))
+    return config_dir
+
+
+def write_pid_file() -> str:
+    p = psutil.Process()
+    pid_file = os.path.join(get_config_dir(), f"{p.pid}.pid")
+    with open(pid_file, "w") as f:
+        f.write(pid_file)
+    return pid_file
+
+
+def terminate_existing_blocker() -> None:
+    this_pid = psutil.Process().pid
+    config_dir = get_config_dir()
+    pid_files = [f for f in os.listdir(config_dir) if f.endswith(".pid")]
+    for pid_file in pid_files:
+        pid = int(pid_file.replace(".pid", ""))
+        if this_pid == pid:
+            continue
+        try:
+            p = psutil.Process(pid)
+            p.terminate()
+        except psutil.NoSuchProcess:
+            pass
+        os.remove(os.path.join(config_dir, pid_file))
+
+
+def init() -> None:
+    terminate_existing_blocker()
+    write_pid_file()
+
+
+def main() -> None:
+    init()
     blocked = [re.compile(f"{word}.*(Firefox|Chromium)", flags=re.IGNORECASE)
                for word in BLOCKED_BROWSER_WORDS]
     while True:
@@ -79,6 +117,5 @@ if __name__ == "__main__":
         if newpid == 0:
             main()
     else:
-        cmd = ["sudo"] + sys.argv
+        cmd = ["sudo", BLOCKER] + sys.argv[1:]
         subprocess.Popen(cmd)
-