Best way to parse command line arguments in C#?

Paul_Stovell_57132 0
Viewed 616700

When building console applications that take parameters, you can use the arguments passed to Main(string[] args).

In the past I've simply indexed/looped that array and done a few regular expressions to extract the values. However, when the commands get more complicated, the parsing can get pretty ugly.

So I'm interested in:

  • Libraries that you use
  • Patterns that you use

Assume the commands always adhere to common standards such as answered here.

command-line-arguments .net c#
20 Answers

I would strongly suggest using NDesk.Options (Documentation) and/or Mono.Options (same API, different namespace). An example from the documentation:

bool show_help = false;
List<string> names = new List<string> ();
int repeat = 1;

var p = new OptionSet () {
    { "n|name=", "the {NAME} of someone to greet.",
       v => names.Add (v) },
    { "r|repeat=", 
       "the number of {TIMES} to repeat the greeting.\n" + 
          "this must be an integer.",
        (int v) => repeat = v },
    { "v", "increase debug message verbosity",
       v => { if (v != null) ++verbosity; } },
    { "h|help",  "show this message and exit", 
       v => show_help = v != null },
};

List<string> extra;
try {
    extra = p.Parse (args);
}
catch (OptionException e) {
    Console.Write ("greet: ");
    Console.WriteLine (e.Message);
    Console.WriteLine ("Try `greet --help' for more information.");
    return;
}
jonp_834440

The WPF TestApi library comes with one of the nicest command line parsers for C# development. I highly recommend looking into it, from Ivo Manolov's blog on the API:

// EXAMPLE #2:
// Sample for parsing the following command-line:
// Test.exe /verbose /runId=10
// This sample declares a class in which the strongly-
// typed arguments are populated
public class CommandLineArguments
{
   bool? Verbose { get; set; }
   int? RunId { get; set; }
}

CommandLineArguments a = new CommandLineArguments();
CommandLineParser.ParseArguments(args, a);
user_71160
abatishchev_419560
user_2308620
user_2847950

I like that one, because you can "define rules" for the arguments, needed or not,...

or if you're a Unix guy, than you might like the GNU Getopt .NET port.

Peter_424750

There is a command line argument parser at http://www.codeplex.com/commonlibrarynet

It can parse arguments using
1. attributes
2. explicit calls
3. single line of multiple arguments OR string array

It can handle things like the following:

-config:Qa -startdate:${today} -region:'New York' Settings01

It's very easy to use.

Admin1
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