diff --git a/docs/config/README.md b/docs/config/README.md index fbf81cf12..0a49f314b 100644 --- a/docs/config/README.md +++ b/docs/config/README.md @@ -152,6 +152,27 @@ format = ''' \$''' ``` +### File Extensions + +Many modules have a `detect_extensions` variable, which takes a list of file extensions to match or not match. +"Negative" extensions, those which should not be matched, are indicated with a leading "!" character. + +Extensions are matched against both the characters after the last dot in a filename, and the characters after +the first dot in a filename. For example, consider the filename `foo.bar.tar.gz`. To see if that matches anything +mentioned in `detect_extensions` we will consider both the characters after the last dot, "gz", and those after +the first dot, "bar.tar.gz". + +We first look for any files matching a negative extension. If there are any, the module is not triggered. + +If there were none, we then look for any files matching a positive extension. + +To see how this works in practice, and why you might want to use negative extensions, consider how a Node +programmer who also works with video might configure the Nodejs module. By default its `detect_extensions` +is `["js", "mjs", "cjs", "ts", "mts", "cts"]`. However, in their video work they also deal with `.video.ts` +and `.audio.ts` files containing MPEG Transport Stream encoded data. They don't want a directory full of +video data to trigger the Nodejs module! So they add two negative extensions to the list: +`["js", "mjs", "cjs", "ts", "mts", "cts", "!audio.ts", "!video.ts"]`. + ## Prompt This is the list of prompt-wide configuration options.