Current File : //lib/python3/dist-packages/shellingham/posix/proc.py
import io
import os
import re
import sys
from ._core import Process
STAT_PPID = 3
STAT_TTY = 6
STAT_PATTERN = re.compile(r"\(.+\)|\S+")
def detect_proc():
"""Detect /proc filesystem style.
This checks the /proc/{pid} directory for possible formats. Returns one of
the followings as str:
* `stat`: Linux-style, i.e. ``/proc/{pid}/stat``.
* `status`: BSD-style, i.e. ``/proc/{pid}/status``.
"""
pid = os.getpid()
for name in ("stat", "status"):
if os.path.exists(os.path.join("/proc", str(pid), name)):
return name
raise ProcFormatError("unsupported proc format")
def _get_stat(pid, name):
path = os.path.join("/proc", str(pid), name)
with io.open(path, encoding="ascii", errors="replace") as f:
# We only care about TTY and PPID -- all numbers.
parts = STAT_PATTERN.findall(f.read())
return parts[STAT_TTY], parts[STAT_PPID]
def _get_cmdline(pid):
path = os.path.join("/proc", str(pid), "cmdline")
encoding = sys.getfilesystemencoding() or "utf-8"
with io.open(path, encoding=encoding, errors="replace") as f:
# XXX: Command line arguments can be arbitrary byte sequences, not
# necessarily decodable. For Shellingham's purpose, however, we don't
# care. (pypa/pipenv#2820)
# cmdline appends an extra NULL at the end, hence the [:-1].
return tuple(f.read().split("\0")[:-1])
class ProcFormatError(EnvironmentError):
pass
def get_process_mapping():
"""Try to look up the process tree via the /proc interface."""
stat_name = detect_proc()
self_tty = _get_stat(os.getpid(), stat_name)[0]
processes = {}
for pid in os.listdir("/proc"):
if not pid.isdigit():
continue
try:
tty, ppid = _get_stat(pid, stat_name)
if tty != self_tty:
continue
args = _get_cmdline(pid)
processes[pid] = Process(args=args, pid=pid, ppid=ppid)
except IOError:
# Process has disappeared - just ignore it.
continue
return processes
Mini Shell