Command

Command UDA is used to customize top-level command as well as subcommands.

This UDA can be chained with functions listed below to adjust different settings.

Signature

Command(string[] names...)

Parameters

names
For subcommands, these are the names of the subcommand that can appear in the command line. If no name is provided then the name of the type that represents the command is used.
For top-level command, this is a name of a program/tool that is appeared on help screen. If multiple names are passed, only first is used. If no name is provided then Runtime.args[0] (a.k.a. argv[0] from main function) is used.

Public members

Usage

Usage allows customize the usage text. By default, the parser calculates the usage message from the arguments it contains but this can be overridden with Usage call. If the custom text contains %(PROG) then it will be replaced by the argv[0] (from main function) in case of top-level command or by a list of commands (all parent commands and current one) in case of subcommand.

Signature

Usage(auto ref ... command, string text)
Usage(auto ref ... command, string function() text)

Parameters

text
Usage text or a function that returns such text.

Usage example

@(Command.Usage("%(PROG) [<parameters>...]"))
struct my_command
{
...
}

Description

Description can be used to provide a description of what the command/program does and how it works. In help messages, the description is displayed between the usage string and the list of the command arguments.

Signature

Description(auto ref ... command, string text)
Description(auto ref ... command, string function() text)

Parameters

text
Text that contains command description or a function that returns such text.

Usage example

@(Command.Description("custom description"))
struct my_command
{
...
}

ShortDescription

ShortDescription can be used to provide a brief description of what the subcommand does. It is applicable to subcommands only and is displayed in Available commands section on help screen of the parent command.

Signature

ShortDescription(auto ref ... command, string text)
ShortDescription(auto ref ... command, string function() text)

Parameters

text
Text that contains short description for a subcommand or a function that returns such text.

Usage example

@(Command.ShortDescription("custom description"))
struct my_command
{
...
}

Epilog

Epilog can be used to provide some custom text that is printed at the end after the list of command arguments.

Signature

Epilog(auto ref ... command, string text)
Epilog(auto ref ... command, string function() text)

Parameters

text
Epilog text or a function that returns such text.

Usage example

@(Command.Epilog("extra info about the command"))
struct my_command
{
...
}

Last modified: 07 August 2024