changeline

Search and replace in lines of files across directories.

Changeline is your basic file search and replace. But it goes beyond regular expressions and paths. You must submit a list of files via STDIN, so it is up to you to select a directory scan program. You can use UNIX find with a *.html wildcard for example.

Furthermore, there is no question about matches spanning lines. Changeline simply sees one line at a time. It uses node readline under the hood.

Finally, changeline is a precision device aimed at altering lines of code without the need for AST processing. You can for example target CSS Class Names in .css/.html and .js/es6 files, and it will plow through ES7 and CSS4 and whatever else comes its way.

Installation

changeline is a command line program, and it is installed via npm which comes along with node. Please install node first, and then run npm install -g changeline to get changeline onto your system.

Usage

After installation via npm install -g changeline you should begin by piping in a list of files separated by a new line. Example of making a dynamic list find . -name example.html -print or cat my-files-to-change.txt where my-files-to-change.txt contains a list of full paths to files needing changes.

Upon a list of paths arriving via STDIN changeline will apply functions to test, and replace data. See test-transformers.js for a more serious example.

module.exports = [
  // JS
  {
    description: "Update bark to meow.",
    search: function(line){ if(line === 'bark') return true; },
    replace: function(line){ return 'meow' },
  },
  // ES6
  {
    description: "Update Bort to Bart.",
    search: line => line === 'Bort',
    replace: line => 'Bart',
  },
]

Usage: changeline [options]

Options:

  -h, --help                 output usage information
  -V, --version              output the version number

  -v, --verbose              Make changeline verbose

The CAS backup concept is similar to Content Addressable Storage prior to altering a file a copy is saved in ~/.changeline a simple index keeps track of hashes, timestamps and original file locations.

  -c, --cas                  Make cas backup before replacement. (recommended)
  --cas-home [path]          Path of cas backups (optional)

A plain old filename.ext.bak is available as well. -b, --backup Make backup before replacement. (optional) --backup-extension [ext] Extension to use for backup files (optional)

You must use the -r/-t flags to do useful things:

  -r, --replace              Perform replacement (required for actual replacement)
  -t, --transformers [path]  Transformer module. (required for specifying what to replace)

The transformer format is ES6 by default and very easy to manage:

module.exports = [
  {
    description: "Update Bort to Bart.",
    search: line => line === 'Bort', // return truthy value to trigger replace
    replace: line => 'Bart', // return updated line content
  },
]

Features and Concepts

Changeline accepts a list of files from the command line via STDIN. This means you can use operating system utilities for file search. example: find . -name test.html -print | changeline -t transformers.js -r -c;

Changeline uses es6 functions for searching an replacing, see transformers.js

Changeline makes backups see --help

Snippets

A quick non-destructive one-liner, run it in changeline's directory:

cp test.html test-tmp.html; echo -e "\nBEFORE"; cat test-tmp.html; echo; find . -name test-tmp.html -print | ./index.js -v -r -c -t ./test-transformers.js; echo -e "\nAFTER"; cat test-tmp.html; echo; rm test-tmp.html;

Links

npm: https://www.npmjs.com/package/changeline
github: https://github.com/fantasyui-com/changeline

MIT License

Written by Captain Fantasy, Copyright (c) 2016 FantasyUI