Mercurial > hg
view tests/printenv.py @ 44998:f2de8f31cb59
pycompat: use os.fsencode() to re-encode sys.argv
Historically, the previous code made sense, as Py_EncodeLocale() and
fs.fsencode() could possibly use different encodings. However, this is not the
case anymore for Python 3.2, which uses the locale encoding as the filesystem
encoding (this is not true for later Python versions, but see below). See
https://vstinner.github.io/painful-history-python-filesystem-encoding.html for
a source and more background information.
Using os.fsencode() is safer, as the documentation for sys.argv says that it can
be used to get the original bytes. When doing further changes, the Python
developers will take care that this continues to work.
One concrete case where os.fsencode() is more correct is when enabling Python's
UTF-8 mode. Py_DecodeLocale() will use UTF-8 in this case. Our previous code
would have encoded it using the locale encoding (which might be different),
whereas os.fsencode() will encode it with UTF-8.
Since we don’t claim to support the UTF-8 mode, this is not really a bug and the
patch can go to the default branch. It might be a good idea to not commit this
to the stable branch, as it could in theory introduce regressions.
author | Manuel Jacob <me@manueljacob.de> |
---|---|
date | Wed, 24 Jun 2020 14:44:21 +0200 |
parents | 2372284d9457 |
children | c102b704edb5 |
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#!/usr/bin/env python # # simple script to be used in hooks # # put something like this in the repo .hg/hgrc: # # [hooks] # changegroup = python "$TESTDIR/printenv.py" <hookname> [exit] [output] # # - <hookname> is a mandatory argument (e.g. "changegroup") # - [exit] is the exit code of the hook (default: 0) # - [output] is the name of the output file (default: use sys.stdout) # the file will be opened in append mode. # from __future__ import absolute_import import argparse import os import sys try: import msvcrt msvcrt.setmode(sys.stdin.fileno(), os.O_BINARY) msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY) msvcrt.setmode(sys.stderr.fileno(), os.O_BINARY) except ImportError: pass parser = argparse.ArgumentParser() parser.add_argument("name", help="the hook name, used for display") parser.add_argument( "exitcode", nargs="?", default=0, type=int, help="the exit code for the hook", ) parser.add_argument( "out", nargs="?", default=None, help="where to write the output" ) parser.add_argument( "--line", action="store_true", help="print environment variables one per line instead of on a single line", ) args = parser.parse_args() if args.out is None: out = sys.stdout out = getattr(out, "buffer", out) else: out = open(args.out, "ab") # variables with empty values may not exist on all platforms, filter # them now for portability sake. env = [(k, v) for k, v in os.environ.items() if k.startswith("HG_") and v] env.sort() out.write(b"%s hook: " % args.name.encode('ascii')) if os.name == 'nt': filter = lambda x: x.replace('\\', '/') else: filter = lambda x: x vars = [ b"%s=%s" % (k.encode('ascii'), filter(v).encode('ascii')) for k, v in env ] # Print variables on out if not args.line: out.write(b" ".join(vars)) else: for var in vars: out.write(var) out.write(b"\n") out.write(b"\n") out.close() sys.exit(args.exitcode)