Monday, 12 May 2014

Regular Expression Command Line Arguments Parser

Here's a simple way to extract a list of switch/flags and their parameters from a command line argument in C#.

Regex regex = new Regex(@"(?< switch> -{1,2}\S*)(?:[=:]?|\s+)(?< value> [^-\s].*?)?(?=\s+[-\/]|$)");

string commands = "--switch value1 --switch2 \"c:\\folder 1\\file1.txt\" -switch-3 value-3 --switch4 -switch5";

List< KeyValuePair< string, string> >  matches = (from match in regex.Matches(commands).Cast< match> ()

select new KeyValuePair< string, string> (match.Groups["switch"].Value, match.Groups["value"].Value)).ToList();

foreach (KeyValuePair< string, string>  _match in matches)
switch:" + _match.Key + "  value:" + _match.Value);

You can pass in a command with multiple switches such as "-switch" or "--switch":

--switch1 value1 --switch2 "c:\folder 2\file2.txt" -switch-3 value-3 --switch4 -switch5

 the regex will extract the flags along with any optional values and return a list of key-value pairs.

I had looked at a couple of solutions such as and but I think this way is a bit simpler and returns better results.

Also, this way allows optional parameters which can contain file paths, you can test here

No comments:

Post a Comment