Using regex to separate parameters

resistance has asked for the wisdom of the Perl Monks concerning the following question:

Hello,

say we have this strange string:

c:\windows\folder.exe with .exe\our.exe prog.com -par1 /param2.exe
[download]

where:

c:\windows\ -folder
folder.exe with .exe\  - folder with blanks in his name
our.exe prog.com  - the program with blanks in his name
-par1 /param2.exe -parameters
[download]

of course it wasn't real example but its easy possible to construct.

I am trying to separate path to executable, executable and parameters. I can separate program with single .exe/.com/.bat extension by using:

=~/(.+?\.\w{3})( +)(.+)/
[download]

but this regexp fail with such extreme example.

It seems only regexp not enough here..

any ideas?

Comment on Using regex to separate parameters Select or Download Code

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Re: Using regex to separate parameters by ikegami (Patriarch) on Jul 06, 2008 at 14:08 UTC
That command is ambiguous and would not work as intended. It should be `"c:\windows\folder.exe with .exe\our.exe prog.com" -par1 /param2.exe` [download] By ambiguous, I mean there's no regexp pattern that will always work, so whatever solution we provide will be wrong. For example, if I give `/^(.*) -/` [download] to extract the path, it'll fail for `c:\files - work\foo` [download]	[reply] [d/l] [select]
Re^2: Using regex to separate parameters by resistance (Beadle) on Jul 06, 2008 at 14:26 UTC
That command is ambiguous yes but can be launched from registry or on many others ways, "" is a command processor completion (cmd.exe), it can work without "" too. for example I can run this from registry: `taskmgr.exe 123` [download] if c:\windows\taskmgr.exe 123.exe exists ("taskmgr.exe 123.exe"). Windows will complete and quote the string. this can misslead because 123 is not a parameter but the part of file name.	[reply] [d/l]
Re^3: Using regex to separate parameters by ikegami (Patriarch) on Jul 06, 2008 at 18:20 UTC
Quoting `CreateProcess`, If you are using a long file name that contains a space, use quoted strings to indicate where the file name ends and the arguments begin; otherwise, the file name is ambiguous. For example, consider the string "c:\program files\sub dir\program name". This string can be interpreted in a number of ways. The system tries to interpret the possibilities in the following order: c:\program.exe files\sub dir\program name c:\program files\sub.exe dir\program name c:\program files\sub dir\program.exe name c:\program files\sub dir\program name.exe So if you want to behave like CreateProcess, you'll have to include file tests in your regexp or solution. But like I said above, this is a wrong answer, but it might be the wrong answer you're looking for. It's wrong cause it fails to handle "`c:\program.exe files\sub`" as "`c:\program.exe files\sub.exe`" if "`c:\program.exe`" exists. It's wrong cause it fails to handle "`c:\program.exe files\sub`" as "`c:\program.exe`" if "`c:\program.exe`" doesn't exists or is currently unavailable (say due to network problems).	[reply] [d/l] [select]
Re^4: Using regex to separate parameters by resistance (Beadle) on Jul 06, 2008 at 18:38 UTC
Re^5: Using regex to separate parameters by ikegami (Patriarch) on Jul 06, 2008 at 19:03 UTC
Some notes below your chosen depth have not been shown here
Re^3: Using regex to separate parameters by ikegami (Patriarch) on Jul 06, 2008 at 17:57 UTC
The fact that it's sometimes optional doesn't mean it's always optional. `>c:\foo bar\test.pl 'c:\foo' is not recognized as an internal or external command, operable program or batch file. >"c:\foo bar\test.pl" Hello World` [download] The same applies for the registry where command lines are expected such as in file associations.	[reply] [d/l]
Re^4: Using regex to separate parameters by resistance (Beadle) on Jul 06, 2008 at 18:14 UTC
Re^5: Using regex to separate parameters by ikegami (Patriarch) on Jul 06, 2008 at 18:17 UTC
Re: Using regex to separate parameters by Anonymous Monk on Jul 06, 2008 at 15:20 UTC
Duplicate what microsoft does, either via Win32::API or Win32::TieRegistry	[reply]