Suggestions for implementation of a command line interface

Question

I am redesigning a command line application and am looking for a way to make its use more intuitive. Are there any conventions for the format of parameters passed into a co

Answer 1

Command line conventions vary from OS to OS, but the convention that's probably gotten both the most use, and the most public scrutiny is the one supported by the GNU getopt package. See http://www.gnu.org/software/libc/manual/html_node/Using-Getopt.html for more info.

It allows you to mix single letter commands, such as -nr, with longer, self-documenting options, such as --numeric --reverse. Be nice, and implement a --help (-?) option and then your users will be able to figure out all they need to know.

Answer 2

Complementing @vonc's answer, don't accept ambiguous abbreviations. Eg:

  myCli.exe describe someThing
  myCli.exe destroy someThing
  myCli.exe des someThing ???

In fact, in that case, I probably wouldn't accept an abbreviation for "destroy"...

Answer 3

If you are using C# try Mono.GetOptions, it's a very powerful and simple-to-use command-line argument parser. It works in Mono environments and with Microsoft .NET Framework.

EDIT: Here are a few features

• Each param has 2 CLI representations (1 character and string, e.g. -a or --add)
• Default values
• Strongly typed
• Automagically produces an help screen with instructions
• Automagically produces a version and copyright screen

Answer 4

Best thing to do is don't assume anything if you can. When the operator types in your application name for execution and does not have any parameters either hit them with a USAGE block or in the alternative open a Windows Form and allow them to enter everything you need.

c:\>FOO

FOO

USAGE FOO -{Option}{Value}

-A Do A stuff
-B Do B stuff

c:\>

Parameter delimiting I place under the heading of a religious topic: hyphens(dashes), double hyphens, slashes, nothing, positional, etc.

You didn't indicate your platform, but for the next comment I will assume Windows and .net

You can create a console based application in .net and allow it to interact with the Desktop using Forms just by choosing the console based project then adding the Windows.Forms, System.Drawing, etc DLLs.

We do this all the time. This assures that no one takes a turn down a dark alley.

Answer 5

Here's a CodeProject article that might help you out...

C#/.NET Command Line Arguments Parser

IF VB is your flavor, here's a separate article (with a bit more guidance related content) to check out...

Parse and Validate Command Line Parameters with VB.NET

Answer 6

One thing I like about certain CLI is the usage of shortcuts.
I.e, all the following lines are doing the same thing

myCli.exe describe someThing
myCli.exe descr someThing
myCli.exe desc someThing

That way, the user may not have to type the all command every time.