macOS support (code only, no build yet)

Programs/ServiceRun.py

@@ -1,8 +1,8 @@
 """Runs a SaraSuite program as a background service where there's no systemd
---user to do it: on Windows (started windowless with pythonw.exe), and on
-Linux with another init system (runit on Void, OpenRC, s6, dinit, ...).
-Started at login (Windows: a shortcut in the Startup folder; Linux: an XDG
-autostart entry) and when SaraSuite or the program's own GUI (e.g. SaraSort
+--user to do it: on Windows (started windowless with pythonw.exe), on macOS,
+and on Linux with another init system (runit on Void, OpenRC, s6, dinit, ...).
+Started at login (Windows: a shortcut in the Startup folder; macOS: a
+LaunchAgent; Linux: an XDG autostart entry) and when SaraSuite or the program's own GUI (e.g. SaraSort
 for SaraSortd) starts it:
 
     python ServiceRun.py <Name> <Script> [<WorkingDir>]
@@ -12,7 +12,8 @@ seconds after it fails (an exception or a non-zero exit), not after a clean
 exit or a stop; its output goes to <Name>.log. Its PID is in <Name>.pid, so
 anything can tell whether it runs, and stop it, without admin rights. Both
 files are in SaraSuite's Services folder: %LOCALAPPDATA%\\SaraSuite\\Services
-on Windows, ~/.local/share/SaraSuite/Services on Linux.
+on Windows, ~/Library/Application Support/SaraSuite/Services on macOS,
+~/.local/share/SaraSuite/Services on Linux.
 
 Installed next to each program that has a service (Programs/<Name>/Manifest.toml).
 """
@@ -20,6 +21,7 @@ Installed next to each program that has a service (Programs/<Name>/Manifest.toml
 import os
 import runpy
 import signal
+import subprocess
 import sys
 import time
 import traceback
@@ -27,6 +29,7 @@ from datetime import datetime
 from pathlib import Path
 
 IsWindows = sys.platform == "win32"
+IsMac = sys.platform == "darwin"
 RestartSeconds = 10  # the unit's RestartSec
 MaxLogBytes = 1_000_000  # then the log starts over, the old one kept as <Name>.log.1
 Stopping = False
@@ -35,22 +38,28 @@ Stopping = False
 def ServicesDir() -> Path:
     if IsWindows:
         Base = Path(os.environ.get("LOCALAPPDATA") or Path.home() / "AppData" / "Local")
+    elif IsMac:
+        Base = Path.home() / "Library" / "Application Support"
     else:
         Base = Path(os.environ.get("XDG_DATA_HOME") or Path.home() / ".local" / "share")
     return Base / "SaraSuite" / "Services"
 
 
 def _AlreadyRunning(PidFile: Path) -> bool:
-    """Linux: whether the PID file's process is another ServiceRun.py still
-    running (not a reused PID). Windows relies on whoever starts it to check."""
+    """Linux and macOS: whether the PID file's process is another
+    ServiceRun.py still running (not a reused PID). Windows relies on whoever
+    starts it to check."""
     if IsWindows:
         return False
     try:
         Pid = int(PidFile.read_text().strip())
         if Pid == os.getpid():
             return False
+        if IsMac:  # no /proc
+            Output = subprocess.run(["ps", "-o", "command=", "-p", str(Pid)], capture_output=True, text=True, timeout=15).stdout
+            return "ServiceRun.py" in Output
         return b"ServiceRun.py" in Path(f"/proc/{Pid}/cmdline").read_bytes()
-    except (OSError, ValueError):
+    except (OSError, ValueError, subprocess.SubprocessError):
         return False