## C.2. `$world->alias`

Abstract

$world->alias function: creates an ALIAS

`void $world->alias(` | `pattern` ,
| `substitution` ,
| [`attributes`] `)`;

`void $world->alias(` | `number` ,
| [`pattern` ,
| [`substitution`]] ,
| [`attributes`] `)`;

Creates a new alias, or edits the alias identified by number. Entered commands will be matched against pattern (a Perl regular expression), and if the pattern matches, the given substitution will be applied. (In a `s/pattern/substitution/` structure.)

Be careful that any part of the command can match. To match only the exact string, use something like `'^command$'`. To match only in the beginning of the line, use `'^command'`.

Atributes is a reference to a hash defining attributes for the alias. Generally the call works like this:

    $world->alias("pattern", "substitution", { attribute1 => value1,
                                               attribute2 => value2, ... })

Possible attributes:

- `pattern`: The pattern to match.

- `substitution`: The substitution to do.

- `ignorecase`: If value evaluates to true, ignore case when matching the pattern.

- `perleval`: If true, the substitution is made passing the "e" flag (`s/pattern/substitution/e`), so substitution should be actually Perl statements to be evaluated when there is a match.

- `enabled`: If value evaluates to true, the alias is enabled, if false, it is disabled and commands are not matched against it.

- `name`: Assigns a name to the alias, so that it can be referenced by name.