RexReplace

> RexReplace is a versatile tool to search and replace text in files from the command line. It's inspired by how developers often need to do quick fixes or one-liners for build scripts.

Key features:

• Easy and intuitive notation makes you trust what you are doing
• Replacement can be javascript code - giving you Turing complete flexibility
• Pinpoint the exact files with glob notation (docs/*.md represents each markdown file in docs/)
• No more brute-forcing the right combination of find, cat, sed, tr, and awk to replace a text pattern in the right files

Install

To use RexReplace from your command line

> npm install -g rexreplace

To use RexReplace from an npm build script:

> yarn add rexreplace --dev
# or
> npm install rexreplace --save-dev

Examples

Let 'foobar' become 'xxxbar' in myfile.md

> rexreplace 'Foo' 'xxx' myfile.md

Hard for your fingers to write on your keyboard? We got you covered with the rr alias for rexreplace

> rr Foo xxx myfile.md

Catch the beginning

Let all markdown files in the docs/ dir get headlines moved one level deeper

> rexreplace '^#' '##' docs/*.md

Using glob notation to pinpoint files

Fix a spell error in all javascript and typescript files in the folders src/ and test/ recursively.

> rexreplace 'foubar' 'foobar' '{src,test}/**/*.{js,ts}'

Dynamically generated content

Let the version number from package.json get into your distribution js files (use the string VERSION in your source files).

> rexreplace 'VERSION' 'require("./package.json").version' -j dist/*.js

Require have been given the alias r and both are expanded to understand relative paths even without ./ prepended. As the file extension is not needed eighter you will get the same result writing:

> rexreplace 'VERSION' 'r("package").version' -j dist/*.js

Reference a matching group

Let 'foobar' become 'barfoo' in myfile.md

> rexreplace '(foo)(.*)' '$2$1' myfile.md

RexReplace defaults to treating € as an alias for $ so the following will do the same as the previous example

> rexreplace '(foo)(.*)' '€2€1' myfile.md

Surviving backslash-escape hell

Let foo[bar] become foo.0.[bar] in myfile.md

> rexreplace '\[' '.0.[' myfile.md

The [ as a literate char must be escaped according to regex. If you run the command as a parameter (this could be from a script in package.json) you need to escape the escape:

"scripts":{
  "fix": "rexreplace '\\[' '.0.[' myfile.md"
}

RexReplace defaults to treating § as an alias for \ so the following give same result:

> rexreplace '§[' '.0.[' myfile.md

"scripts":{
  "fix": "rexreplace '§[' '.0.[' myfile.md"
}

More relevant examples

Per file info

Add creation time, name of the file and human readable file size as the first line in each file in test-run recursively.

> rexreplace '^' 'ctime_ + name_ + size + nl' -j -M 'dist/**/*.*'

Matching pairs

Let both "foo 'is' bar" and ' foo "was" bar' ' become » foo ... bar « independent of using ' or "

> rexreplace '(['"])([^\1]+)\1' '» $2 «' myfile.md

Usage

> rexreplace pattern replacement [fileGlob|option]+