Command Information

Define this command for me!

Each command you define in your shell must provide a new instance of the CommandInfo class holding details about the specified command. The new instance of the class can be made using one of the constructors defined below:

public CommandInfo(string Command, string HelpDefinition, CommandArgumentInfo[] CommandArgumentInfo, BaseCommand CommandBase, CommandFlags Flags = CommandFlags.None)
public CommandInfo(string Command, string HelpDefinition, BaseCommand CommandBase, CommandFlags Flags = CommandFlags.None)

where:

• Command: The command

• HelpDefinition: The brief summary of what the command does

• CommandArgumentInfo: Array of argument information about your command (can be omitted)

• CommandBase: An instance of the BaseCommand containing command execution information

• CommandFlags: All command flags

To implement CommandArgumentInfo, call the constructor either with no parameters, which implies that there is no argument required to run this command, or with the following options listed below.

public CommandArgumentInfo()
public CommandArgumentInfo(bool AcceptsSet)
public CommandArgumentInfo(bool AcceptsSet, bool infiniteBounds)
public CommandArgumentInfo(CommandArgumentPart[] Arguments)
public CommandArgumentInfo(CommandArgumentPart[] Arguments, bool AcceptsSet)
public CommandArgumentInfo(CommandArgumentPart[] Arguments, bool AcceptsSet, bool infiniteBounds)
public CommandArgumentInfo(SwitchInfo[] Switches)
public CommandArgumentInfo(SwitchInfo[] Switches, bool AcceptsSet)
public CommandArgumentInfo(SwitchInfo[] Switches, bool AcceptsSet, bool infiniteBounds)
public CommandArgumentInfo(CommandArgumentPart[] Arguments, SwitchInfo[] Switches)
public CommandArgumentInfo(CommandArgumentPart[] Arguments, SwitchInfo[] Switches, bool AcceptsSet)
public CommandArgumentInfo(CommandArgumentPart[] Arguments, SwitchInfo[] Switches, bool AcceptsSet, bool infiniteBounds)

where:

• Arguments: Defines the command arguments

• Switches: Defines the command switches

• AcceptsSet: Whether to accept the -set switch

• infiniteBounds: Whether to accept infinite number of arguments or not

For commands that require more than just simple argument checking as specified in the CommandArgumentPart instances, you can use the ArgChecker property to set it to a function delegate that checks all the arguments, with the command parameter info as the first argument. Such functions must return 0 to continue execution. Else, the command execution will not continue and the last error code will be set to what the function returns.

This is an example for the alarm command:

CommandInfo for alarm

new CommandInfo("alarm", /* Localizable */ "Manage your alarms",
    [
        new CommandArgumentInfo(
        [
            (...)
        ])
        {
            ArgChecker = (cp) => AlarmCommand.CheckArgument(cp, "start")
        },
        (...)
    ], new AlarmCommand(), CommandFlags.Strict),

Alarm command code

internal static int CheckArgument(CommandParameters parameters)
{
    (...)
}

For CommandArgumentPart instances, consult the below constructor to create an array of CommandArgumentPart instances when defining your commands:

public CommandArgumentPart(bool argumentRequired, string argumentExpression, Func<string[], string[]> autoCompleter = null, bool isNumeric = false, string[] exactWording = null, string argumentDesc = "")

where:

• argumentRequired: Is this argument part required?

• argumentExpression: Command argument expression

• autoCompleter: Auto completion function delegate

  • The first string[] denotes the list of last passed arguments

  • The second string[] (output) denotes the suggestions returned

• isNumeric: Whether this argument part accepts numeric values only

• exactWording: If not empty, the user must write one of the words declared in this variable for this argument to be satisfied

• argumentDesc: Argument description that shows up in the help entry

Usually, there is no need for you to cut the string to the required position; the shell does it to every single autocomplete result that is given.

Auto-completion for commands

Commands can have auto-completion set up, so that program users can use their TAB key as means to automatically complete the expression for a command, depending on argument positioning. The shell, when TAB is pressed, will select one of the following completers:

• If the auto completer is specified, then, regardless of whether the expression represents the selection (expressions containing the slash / character) or not, the auto completer specified in the constructor will be called.

• If the auto completer is not specified, then it will go through the following completers:

  • The shell goes through the list of known completion expressions according to the argument expression, which are the following:

    • cmd, command: List of all available commands

    • shell: List of all available shells

    • $variable: List of all MESH variables

  • If the expression is not listed in any of the known expressions list, it'll check for the selection indicator characters (the slash / key).

    • For example, the true/false expression will generate an auto completer that completes the two words: true and false.

  • In case there is none, the shell will use the default auto completer, which fetches possible files and folders on your current working directory.

The known expressions list can be manipulated, by registering and unregistering a completion expression. You can use one of the following functions found in the CommandAutoCompletionList class:

• RegisterCompletionFunction(): Registers the completion function using a name and a function that returns a list of possible completions.

• UnregisterCompletionFunction(): Unregisters the completion function by name

• IsCompletionFunctionRegistered(): Determines whether the completion function is registered or not

• IsCompletionFunctionBuiltin(): Determines whether the completion function is registered as a built-in completer or not

Here's a simple example as to how to define such completion function:

// Completion function registration
CommandAutoCompletionList.RegisterCompletionFunction("text", (_) => { return ["Hello", "Hi"]; });

ShellManager.RegisterShell("TestShell", new TestShellInfo());
ShellManager.StartShell("TestShell");
ShellManager.UnregisterShell("TestShell");

// Completion function unregistration
CommandAutoCompletionList.UnregisterCompletionFunction("text");

Command argument part with options

In case you want to expressively specify the options without having to use default values for all parameters to set a certain parameter, you can use the CommandArgumentPartOptions overload:

public CommandArgumentPart(bool argumentRequired, string argumentExpression, CommandArgumentPartOptions options)