Plugins can be configured using a powerful template syntax, this allows editing
the plugin messages to override them.

The syntax is `?{}` where `?` is replaced by one of the token defined below.
Braces are mandatory and cannot be ommited. To write a literal template
construct, prepend the token twice.

The following templates are available:

- `%`, date and time (see Time section),
- `#{name}`, name will be substituted from the keywords (see Keywords section),
- `${name}`, name will be substituted from the environment variable (see
  Environment variables),
- `@{attributes}`, the attributes will be substituted to IRC colors (see
  Attributes).

# Time

When you can use patterns, the date and time may be used just like `strftime(3)`
so for the hours and minutes, you can use **%H:%M**.

# Environment variables

If supported, you can use environment variables like **${HOME}**. Please note
that braces are mandatory.

# IRC attributes

The attribute format is composed of three parts, foreground, background and
modifiers, each separated by a comma.

note: attributes and colors are not supported by all IRC clients.

warning: do not use colors and attributes outside IRC (e.g. for storing text in
         files) because escape codes are only valid in IRC context.

## Available colors

- white,
- black,
- blue,
- green,
- red,
- brown,
- purple,
- orange,
- yellow,
- lightgreen,
- cyan,
- lightcyan,
- lightblue,
- pink,
- grey,
- lightgrey.

## Available attributes

- bold,
- italic,
- strike,
- reset,
- underline,
- underline2,
- reverse.

# Shell attributes

Like IRC attributes, it's possible to specify colors and attributes in some
places such as logger configuration.

Warning: colors are not supported on all platforms.

## Available colors

- black,
- red,
- green,
- orange,
- blue,
- purple,
- cyan,
- white,
- default.

## Available attributes

- bold,
- dim,
- underline,
- blink,
- reverse,
- hidden.

# Keywords

Keywords are arbitrary names that are replaced depending on the context. They
are usually available to configure plugins.

## Predefined keywords

Here's the list of keywords that a lot of plugins uses:

- #{channel}, the channel name,
- #{command}, the command to invoke the plugin, e.g. `!ask`,
- #{message}, a message (depending on context),
- #{origin}, the full user, e.g. `markand!~mkd@localhost`,
- #{nickname}, the short nickname,
- #{plugin}, the plugin name,
- #{server}, the current server name,
- #{topic}, the topic,
- #{target}, a target, e.g. a person who gets kicked.

warning: these keywords can be overriden by plugins.

# Examples

Valid constructs:

- `\#{target}, welcome`: if target is set to "irccd", becomes "irccd, welcome",
- `@{red}#{target}`: if target is specified, it is written in red.

Invalid or literals constructs:

- `\#{target}`: will output "#{target}",
- `##`: will output "##",
- `#target`: will output "#target",
- `#{target`: will throw an error.

Colors & attributes:

- `@{red,blue}`: will write text red on blue background,
- `@{default,yellow}`: will write default color text on yellow background,
- `@{white,black,bold,underline}`: will write white text on black in both bold
  and underline.

Using the logger plugin:

For instance, using the **logger** plugin, it's possible to customize the
pattern to use when someone joins a channel like that:

    #{origin} joined #{channel}

The keyword **#{origin}** will be substituted to the nickname and **#{channel}**
to the channel name.