Mercurial > hg
view tests/md5sum.py @ 31478:9335dc6b2a9c
pager: avoid shell=True on subprocess.Popen for better errors (issue5491)
man(1) behaves as poorly as Mercurial without this change. This cribs
from git's run-command[0], which has a list of characters that imply a
string that needs to be run using 'sh -c'. If none of those characters
are present in the command string, we can use shell=False mode on
subprocess and get significantly better error messages (see the test)
when the pager process is invalid. With a complicated pager command
(that contains one of the unsafe characters), we behave as we do today
(which is no worse than git manages.)
I briefly tried tapdancing in a thread to catch early pager exits, but
it's just too perilous: you get races between fd duping operations and
a bad pager exiting, and it's too hard to differentiate between a
slow-bad-pager result and a fast-human-quit-pager-early result.
I've observed some weird variation in exit code handling in the "bad
experience" case in test-pager.t: on my Mac hg predictably exits
nonzero, but on Linux hg always exits zero in that case. For now,
we'll work around it with || true. :(
0: https://github.com/git/git/blob/cddbda4bc87b9d2c985b6749b1cf026b15e2d3e7/run-command.c#L201
author | Augie Fackler <augie@google.com> |
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date | Wed, 15 Mar 2017 20:33:47 -0400 |
parents | 8d1cdee372e6 |
children | 3a64ac39b893 |
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#!/usr/bin/env python # # Based on python's Tools/scripts/md5sum.py # # This software may be used and distributed according to the terms # of the PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2, which is # GPL-compatible. from __future__ import absolute_import import os import sys try: import hashlib md5 = hashlib.md5 except ImportError: import md5 md5 = md5.md5 try: import msvcrt msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY) msvcrt.setmode(sys.stderr.fileno(), os.O_BINARY) except ImportError: pass for filename in sys.argv[1:]: try: fp = open(filename, 'rb') except IOError as msg: sys.stderr.write('%s: Can\'t open: %s\n' % (filename, msg)) sys.exit(1) m = md5() try: for data in iter(lambda: fp.read(8192), ''): m.update(data) except IOError as msg: sys.stderr.write('%s: I/O error: %s\n' % (filename, msg)) sys.exit(1) sys.stdout.write('%s %s\n' % (m.hexdigest(), filename)) sys.exit(0)