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alias_command

Synopsis

alias
alias <alias-name>
alias -<alias-name>
alias <alias-name> (<argument-list>) {block}

Summary

Aliases are /commands and $function()s that you create that complement the built in /commands and $function()s.

Aliases may call built in commands, other aliases, or evaluate expressions.

Aliases may (optionally) return a value, which will be used if you call the alias as a $function().

Forms

If you provide no arguments, alias will display all your aliases.

If you provide an alias name, or an initial part of an alias name, it will display all aliases that start with what you provide

If you provide only an alias name, prefixed with a hyphen (“-name”), it will remove that alias.

If you provide an alias name, a block statement, and an (optional) arglist, the alias will be created (or replaced if it already exists).

Alias names

Alias names can contain any character except a nul (ascii 0x00).

Because of how ircII treats a[b][c] as syntactically identical to a.b.c, if your alias name contains square brackets, they will be silently changed to dot-notation

foo[bar][baz]

becomes

foo.bar.baz

You should avoid beginning an alias name with a left parenthesis (“(”), left curly brace (“{”), or at-sign (“@”), because they conflict with ircII syntax, and can make it difficult to call your alias.

Local variables and Return value

Aliases can set local variables which are destroyed when the alias is finished. Aliases are automatically provided with a local variable “FUNCTION_RETURN” which is used for the alias's return value. You can assign a value directly to it, or use the return command. If the alias is called as a command, then the return value is ignored by the caller.

Aliases overrule built in commands

Aliases take precedence over both built-in commands and built-in functions (built-in commands only in EPIC4). You must take special measures to call the built-in command or function if you have overridden it with an alias.

If you need to call a builtin command after defining an alias with the same name, use two slashes:

    //builtincommand args

If you need to call a builtin function after defining an alias with the same name, use two colons before the name:

    ::builtinfunction(args)

Examples

To create an alias that overloads a command, and calls it too:

    alias lusers {
       echo -- User Information for ${[$*] ? [$*] : S}
       //lusers $*
       echo -- End User Information
    }

To create a function that returns the sum of two inputs:

    alias sum {
       @ function_return = [$0] + [$1]
    }

To create an alias that uses the new function:

    alias showsum {
       echo The sum of $0 and $1 is $sum($0 $1)
    }

To use the new /showsum command to compute a sum:

    /showsum 4 5

Using the alias as in the previous example will display the following:

    The sum of 4 and 5 is 9

History

The alias command first appeared in ircII.

#$EPIC: alias_command.txt,v 1.7 2009/08/13 04:25:48 jnelson Exp $

alias_command.txt · Last modified: 2023/09/19 02:04 by 127.0.0.1