cli-d 0.1.1

CLI.d

CLI.d is a library that allows super easy, yet powerful parsing of command line arguments. It supports the following features:

• Easy linkage from flags to struct members.
• Long and short flags (e.g.: -f and --file flags).
• Combining multiple short flags (e.g.: -rvf instead of -r -v -f or --recursive --verbose --file)
• Automatic generation of help file during compile time.
• Marking flags as required.
• Validating arguments during parsing.
• Automatic error messages.

Basics

In order to parse command line arguments using CLI.d, an arguments struct first needs to be created. An arguments struct is any type of struct that has members with the attribute @Parameter. After creating the struct it can be parsed using the parseArguments function.

import clid;

private struct MyConfig
{
  @Parameter("foo", 'f')
  string myArgument;
}

void main()
{
  auto config = parseArguments!MyConfig();
}

Note that each argument must have a long flag, but may optionally have a short flag.

private struct MyConfig
{
  @Parameter("foo")
  string onlyLongFlag

  @Parameter("bar", 'b')
  string bothLongAndShortFlag;
}

Validation

Arguments can automatically be validated. For instance, to mark an argument as being required, simply adding @Required will cause an error message to be displayed if the user forgot to add it.

private struct MyConfig
{
  @Parameter("foo", 'f')
  @Required
  string myArgument;
}

If one of the parameters has to refer to a file, a validator can be used. Adding a validator will make sure that the argument always refers to a valid file. If not, a proper error message will be displayed.

private struct MyConfig
{
  @Parameter("file", 'f')
  @Validate!isFile
  @Required
  string myArgument;

  @Parameter("file", 'f')
  @Validate!isFile
  string optionalFile;
}

Help files

The parseArguments function will automatically handle the flags -h and --help, but in order to have a really nice help file descriptions have to be added to each member. This is done using @Description

private struct MyConfig
{
  @Parameter("file")
  @Description("The file to read")
  string file;
}

Examples

Check working examples in the examples directory. Each example can be compiled using dub build --single [EXAMPLE].