Problem parsing cmdline parameter quoted with a trailing \

[tungwaiyip]

BPO	1436900
Nosy	@birkenfeld

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = <Date 2006-02-23.17:35:51.000>
created_at = <Date 2006-02-22.18:38:27.000>
labels = ['interpreter-core', 'invalid']
title = 'Problem parsing cmdline parameter quoted with a trailing \\'
updated_at = <Date 2006-02-23.17:35:51.000>
user = 'https://bugs.python.org/tungwaiyip'

bugs.python.org fields:

activity = <Date 2006-02-23.17:35:51.000>
actor = 'tungwaiyip'
assignee = 'none'
closed = True
closed_date = None
closer = None
components = ['Interpreter Core']
creation = <Date 2006-02-22.18:38:27.000>
creator = 'tungwaiyip'
dependencies = []
files = []
hgrepos = []
issue_num = 1436900
keywords = []
message_count = 6.0
messages = ['27598', '27599', '27600', '27601', '27602', '27603']
nosy_count = 3.0
nosy_names = ['georg.brandl', 'tungwaiyip', 'splitscreen']
pr_nums = []
priority = 'normal'
resolution = 'not a bug'
stage = None
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue1436900'
versions = ['Python 2.4']

[tungwaiyip]

This problem happens in launching Python from Windows.
A quoted pathname is used as parameter. If and only if
the pathname is ended with a trailing \, it is treated
as an escape character.

p.py
-------------------------------------------------------

import sys
from pprint import pprint
pprint(sys.argv)

---

Note slash inside the quote is treated as path
separators

g:\usr\bin>c:\python24\python.exe g:\usr\bin\p.py "
tung\wai\yip" wai
['g:\\usr\\bin\\p.py', 'tung\\wai\\yip', 'wai']

However the trailing \ is treated as an escape
character for the quote. Only command line parameter
is presented in sys.argv.

g:\usr\bin>c:\python24\python.exe g:\usr\bin\p.py "
tung\wai\yip\" wai
['g:\\usr\\bin\\p.py', 'tung\\wai\\yip" wai']

[birkenfeld]

Logged In: YES
user_id=849994

Is that Python-specific? I thought sys.argv is the cmdline
args as Python gets them from Windows.

[splitscreen]

Logged In: YES
user_id=1126061

After having a quick look it appears as though python is in
fact stripping the trailing '\'. the argv array that the
python interpreter is passed contains the backslash so it
must be doing away with it.

[splitscreen]

Logged In: YES
user_id=1126061

Whoops, my bad. Its a windows issue, not a python one.

[birkenfeld]

Logged In: YES
user_id=849994

OK, closing.

[tungwaiyip]

Logged In: YES
user_id=561546

I don't completely follow your logic. But I have reproduce
this with Java so it looks very likely that it is a Windows
bug. In addition, a workaround is to add as extra \ at the
end of the first argument if you know it is going to end in
\. This is illustrated in the last example.

P.java
------------------------------------------------------------

public class P {
  public static void main(String argv[]) throws Exception {
    for (int i=0; i < argv.length; i++) {
      System.out.println("argv " + i + " " + argv[i]);
    }
  }
}

---

BAD
c:\>java P "tung\wai\yip\" wai
argv 0 tung\wai\yip" wai

GOOD
c:\>java P "tung\wai\yip\\" wai
argv 0 tung\wai\yip\
argv 1 wai
-----------------------------------------------------------