second commit

env/lib/python3.11/site-packages/shellingham/posix/ps.py

@@ -0,0 +1,51 @@
+import errno
+import subprocess
+import sys
+
+from ._core import Process
+
+
+class PsNotAvailable(EnvironmentError):
+    pass
+
+
+def iter_process_parents(pid, max_depth=10):
+    """Try to look up the process tree via the output of `ps`."""
+    try:
+        cmd = ["ps", "-ww", "-o", "pid=", "-o", "ppid=", "-o", "args="]
+        output = subprocess.check_output(cmd)
+    except OSError as e:  # Python 2-compatible FileNotFoundError.
+        if e.errno != errno.ENOENT:
+            raise
+        raise PsNotAvailable("ps not found")
+    except subprocess.CalledProcessError as e:
+        # `ps` can return 1 if the process list is completely empty.
+        # (sarugaku/shellingham#15)
+        if not e.output.strip():
+            return
+        raise
+    if not isinstance(output, str):
+        encoding = sys.getfilesystemencoding() or sys.getdefaultencoding()
+        output = output.decode(encoding)
+
+    processes_mapping = {}
+    for line in output.split("\n"):
+        try:
+            _pid, ppid, args = line.strip().split(None, 2)
+            # XXX: This is not right, but we are really out of options.
+            # ps does not offer a sane way to decode the argument display,
+            # and this is "Good Enough" for obtaining shell names. Hopefully
+            # people don't name their shell with a space, or have something
+            # like "/usr/bin/xonsh is uber". (sarugaku/shellingham#14)
+            args = tuple(a.strip() for a in args.split(" "))
+        except ValueError:
+            continue
+        processes_mapping[_pid] = Process(args=args, pid=_pid, ppid=ppid)
+
+    for _ in range(max_depth):
+        try:
+            process = processes_mapping[pid]
+        except KeyError:
+            return
+        yield process
+        pid = process.ppid