Only quote arguments during cmdify if needed

[uranusjr]

Windows built-in commands don't always work well with quotes.

rem The path can be interpreted correctly, but not "/w".
dir "/w" "C:\"

rem Outputs "foo" "bar", with quotes!
echo "foo" "bar"

The solution (I think) is to be less aggressive. Only quote things if they need to be quoted (i.e. contains whitespaces).

[techalchemy]

knock this off, I have the canonical function already - I stole this from stackoverflow where they insisted that it was the correct way to handle this problem on windows

def escape_grouped_arguments(s):
    """Prepares a string for the shell (on Windows too!)

    Only for use on grouped arguments (passed as a string to Popen)
    """
    if s is None:
        return None

    # Additional escaping for windows paths
    if os.name == "nt":
        s = "{}".format(s.replace("\\", "\\\\"))
    return '"' + s.replace("'", "'\\''") + '"'

[techalchemy]

(this wasn't that long ago and the insistence was that there is no better alternative in any part of any library that can handle this -- it seemed true then and AFAIK this is pretty close)

To summarize my concern / question more broadly though, since I haven't had a chance to really review and I don't have a problem replacing this on principle, just in practical terms -- what is the advantage to doing regex parsing here / is it really needed?

[uranusjr]

@techalchemy The use case is a bit different here. That function is good if you already have a string, but here we have a list of arguments, i.e. ["dir", "/w", "C:\Program Files"]. The problem is to decide when to quote, not how (that is easy, and the two solutions are logically equivalent).

[techalchemy]

[shellquote(arg) for arg in args if " " in arg] (if thats where you landed on this I agree)

[uranusjr]

That won’t work either because it escapes single quotes, and Windows don’t want you to.

import shlex
import os
import re


def escape_grouped_arguments(s):
    """Prepares a string for the shell (on Windows too!)

    Only for use on grouped arguments (passed as a string to Popen)
    """
    if s is None:
        return None

    # Additional escaping for windows paths
    if os.name == "nt":
        s = "{}".format(s.replace("\\", "\\\\"))
    return '"' + s.replace("'", "'\\''") + '"'


def my_quote(s):
    return '"{0}"'.format(re.sub(r'(\\*)"', r'\1\1\\"', s))

s = "print('hello world')"
print('SO:   ', 'python', '-c', escape_grouped_arguments(s))
print('shlex:', 'python', '-c', shlex.quote(s))
print('mine: ', 'python', '-c', my_quote(s))

SO:    python -c "print('\''hello world'\'')"
shlex: python -c 'print('"'"'hello world'"'"')'
mine:  python -c "print('hello world')"

Only mine works correctly in cmd.exe.

[techalchemy]

Damn. You should make a library out of this or something