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NoTrigger is an anti-abuse plugin that modifies outFilter to prevent triggering other bots.
## Short description
In short, NoTrigger works by:
- Prepending messages that start with a symbol (```!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~```) or any configured prefixes with a [zero width space](https://en.wikipedia.org/wiki/Zero-width_space) (ZWSP), since these are often used as prefixes for bots. This has the effect of being completely invisible, and tricks most bots into ignoring yours!
- Prepending messages with a ZWSP if the channel is set to block colors and a message begins with a formatting code (sneaky attackers can otherwise do something like `\x02!echo hello` to bypass filters).
- Optionally, prepending messages with a ZWSP if they match `<something>: ` or `<something>, `, since some bots are taught to respond to their nicks.
- Optionally, blocking all channel-wide CTCPs (except for ACTION).
- Optionally, stripping the bell character from any outgoing messages.
- Optionally, appending messages that end with any configured suffixes with a ZWSP.
To enable NoTrigger, set the `plugins.NoTrigger.enable` config option `True` for the channels in question. You can find a list of NoTrigger's options (toggling the things mentioned above) by running `config list plugins.NoTrigger`.
## Longer description/Backstory on why I wrote this
Sometimes when you have a public development channel with many bots residing in it, someone will come along and do something really evil: that is, create a huge message loop by chaining all your innocent bots together!
For example:
```
<evilperson> !echo @echo $echo &echo abcdefg
<bot1> @echo $echo &echo abcdefg
<bot2> $echo &echo abcdefg
<bot3> &echo abcdefg
...
```
NoTrigger aims to solve some of these issues by prepending messages that start with commonly-used bot triggers with a [zero-width space](https://en.wikipedia.org/wiki/Zero-width_space) or ZWSP. These are non-printing characters, which are essentially invisible to people's clients. (We're going to use a space to represent the ZWSP in the examples below, just so you can see a difference.)
For example:
```
<evilperson> !echo @echo $echo &echo abcdefg
<securedbot> @echo $echo &echo abcdefg
...
```
Boom. Problem solved, right? Well, almost.
Some bots will also respond to their nick!
```
<evilperson> !echo bot2: echo bot3: echo i lost the game!
<bot1> bot2: echo bot3: echo i lost the game!
<bot2> bot3: echo i lost the game!
...
```
This is slightly harder to parse, so we have to check if a message matches `<something>: <text>` or `<something>, <text>` (where `<something>` can be used as the name of a bot).
OKAY OKAY, now our bot is really foolproof, right?
**ALMOST!** Then there are the truly evil ops (shoutout to [@jacob1](https://github.com/jacob1)) that start messing with your bot by introducing colour stripping! :D
Fortunately, we'll append these message with a space too! (when the channel is set to strip colours, of course.)
##### Before:
```
Channel is set +c.
<evilperson> !bold "bot2: echo bot3: echo i lost the game!"
<unsecuredbot> bot2: echo bot3: echo i lost the game!
<bot2> bot3: echo i lost the game!
...
```
##### After:
```
Channel is set +c.
<evilperson> !bold "bot2: echo bot3: echo i lost the game!"
<securedbot> bot2: echo bot3: echo i lost the game!
```
That's all! Find any more ways to abuse a poor, innocent bot? Let me know on the issue tracker! :stuck_out_tongue_closed_eyes:
(and no, not all bots use a hostmask matching `*!*@*/bot/*`, not even on freenode!)