taskmgr.exe 123
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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).

Thanks ikegami for your explanation, actually my script run on linux and it parse data which it get from windows registry. This input data dont follow logic and can be simple malicious. I cannot use any of Win32 modules which using XS part. The command is ambiguous because it intend to be ambiguous to misslead users and standard programs like antiviruses etc.

right now I stick to:


sub find_parameters {
    my $input = $_[0];
    if($input =~ /^(.+?\.\w{3})$/){
        print "only one executable: $input\n";
    }elsif($input =~ /^(.+?\.\w{3})( +)([\/\-].+)$/ && -f $1 ){
        print "$1 with parameters $3\n";
    }elsif($input =~ /^“(.+)”$/){
                # strip quotes and parse again
        find_parameters($1);
    }else{
        print "not parsed: $input\n";
    };
};
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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
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The same applies for the registry where command lines are expected such as in file associations.

'c:\foo' is not recognized as an internal or external command,

this error message occur because you type this manually in cmd.exe

in cmd.exe this will work:

foo.exe bar
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if "foo.exe bar.exe" exists in the %path%

this was not my question, thanks anyway