init

desktop/kadence_desktop/blocking/processes.py

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+"""Application blocking by watching `/proc`.
+
+No root needed: these are your own processes. The scan reads `/proc/*/comm` and
+the cmdline, matches against the configured names, and either terminates the
+process (SIGTERM, then SIGKILL if it ignores us) or just reports it, depending
+on the setting.
+
+Matching is deliberately forgiving — `steam` should catch `steamwebhelper`, and
+`telegram` should catch `Telegram` — but it never matches ourselves, PID 1, or
+anything outside the current user's processes.
+"""
+
+from __future__ import annotations
+
+import logging
+import os
+import signal
+import time
+from dataclasses import dataclass
+from pathlib import Path
+
+log = logging.getLogger(__name__)
+
+_SELF_MARKERS = ("kadence", "python3 -m kadence_desktop")
+
+
+@dataclass(slots=True)
+class RunningApp:
+    pid: int
+    name: str
+    cmdline: str
+    matched: str
+
+
+def _read(path: Path) -> str:
+    try:
+        return path.read_text("utf-8", errors="replace")
+    except OSError:
+        return ""
+
+
+def scan(patterns: list[str]) -> list[RunningApp]:
+    """Every live process of this user matching one of `patterns`."""
+    wanted = [pattern.strip().lower() for pattern in patterns if pattern.strip()]
+    if not wanted:
+        return []
+
+    uid = os.getuid()
+    self_pid = os.getpid()
+    found: list[RunningApp] = []
+
+    for entry in Path("/proc").iterdir():
+        if not entry.name.isdigit():
+            continue
+        pid = int(entry.name)
+        if pid in (1, self_pid):
+            continue
+        try:
+            if entry.stat().st_uid != uid:
+                continue
+        except OSError:
+            continue
+
+        comm = _read(entry / "comm").strip()
+        if not comm:
+            continue
+        cmdline = _read(entry / "cmdline").replace("\x00", " ").strip()
+        haystack = f"{comm} {cmdline}".lower()
+        if any(marker in haystack for marker in _SELF_MARKERS):
+            continue
+
+        match = next((pattern for pattern in wanted if pattern in haystack), None)
+        if match:
+            found.append(RunningApp(pid=pid, name=comm, cmdline=cmdline[:200], matched=match))
+    return found
+
+
+def terminate(app: RunningApp, *, grace_seconds: float = 2.0) -> bool:
+    """Ask the process to quit, then insist. True when it is gone."""
+    try:
+        os.kill(app.pid, signal.SIGTERM)
+    except ProcessLookupError:
+        return True
+    except PermissionError:
+        log.warning("not allowed to stop %s (pid %s)", app.name, app.pid)
+        return False
+
+    deadline = time.monotonic() + grace_seconds
+    while time.monotonic() < deadline:
+        try:
+            os.kill(app.pid, 0)
+        except ProcessLookupError:
+            return True
+        time.sleep(0.1)
+
+    try:
+        os.kill(app.pid, signal.SIGKILL)
+    except ProcessLookupError:
+        return True
+    except PermissionError:
+        return False
+    return True