HashMark

HashMark is a small utility which takes a file (or sdtin) as input, and writes the contents of the input to a file named with a hash digest of the file. This is useful for cache busting sticky caches - files can have far future expires headers and when the code changes, a new filename is created.

Examples:

Shell

cat file.js | ./bin/hashmark 'file.{hash}.js' # Writes to test.3eae1599bb7f187b86d6427942d172ba8dd7ee5962aab03e0839ad9d59c37eb0.js
> Computed hash: 3eae1599bb7f187b86d6427942d172ba8dd7ee5962aab03e0839ad9d59c37eb0
>
cat file.js | ./bin/hashmark -l 8 'file.{hash}.js' # Writes to test.3eae1599.js
> Computed hash: 3eae1599
>
cat file.js | ./bin/hashmark -l 4 -d md5 'dist/{hash}.js' # Writes to dist/cbd8.js
> Computed hash: cbd8
>

hashmark also supports file globs - meaning you can read in many files and it will output hashed versions of each:

./bin/hashmark path/to/*.js 'dist/{name}.{hash}.js'
./bin/hashmark path/to/{filea,fileb,filec}.js 'dist/{name}.{hash}.js'
./bin/hashmark **.js 'dist/{dir}/{name}.{hash}.js'
./bin/hashmark **.{js,css} 'dist/{dir}/{name}.{hash}.{ext}'

The hashmark command will output the some JSON stdout with a map of filenames and their new hashes, meaning you can pipe the hash to other programs. To make hashmark completely silent - simply pass the --silent or -s flag.

./bin/hashmark -l 4 file.js 'dist/{hash}.js' --silent

You can also output the JSON map to a file, by passing the --asset-map or -m flag. It will still be logged to stdout unless you pass --silent

./bin/hashmark -l 4 file.js 'dist/{hash}.js' --asset-map assets.json

Progamatically

The hashmark function can be used programatically. You can pass it a String, Buffer or Stream as the first argument, an options object as the second argument, and a callback as the third.

The callback receives an error as the first argument (or null) and an object which maps each given file to the newly hashed file name.

var hashmark = require('hashmark');
var file = fs.createReadStream('file.js');

hashmark(file, { length: 8, digest: 'md5', 'pattern': '{hash}'}, function (err, map) {
    console.log(map);
});

The function also returns an event emitter which emits error, file and end events. File events get fired when an individual file has been hashed, and the end event is fired when all have been done. file is given two arguments - the files old name, and the new calculated filename (given the template string), and the end event is given an object mapping of all files.

var hashmark = require('hashmark');
var file = fs.createReadStream('file.js');

hashmark(file, { length: 8, digest: 'md5', pattern: 'hash'})
    .on('file', function (oldFileName, newFileName) {
        console.log('File hashed!', oldFileName, newFileName);
    })
    .on('end', function (jsonMap) {
        console.log('~FIN');
    })

Files can be a single Stream, or filename String, or an Array of Streams and/or filename Strings. Globbing is not supported here (the globbing functionality lives in the command line).

var hashmark = require('hashmark');
var file = fs.createReadStream('file.js');

hashmark([file, 'file2.js'], { length: 8, digest: 'md5', file: 'file.#.js'}, function (err, hash) {
    console.log('File written to file.' + hash + '.js');
    console.log(hash);
});

Contributing

This is such a small utility - there's very little point in contributing. If it doesn't do something that you really think it should, feel free to raise an issue - just be aware I might say no. If you can make it faster/better/stronger without changing the API/functionality then send a PR!