get-branch-name.js

// Initialise vars
var gitOutput = "",
    branch = null;

// Start reading stdin
process.stdin.resume();

// Store read in chunks
process.stdin.on('data', function (chunk) {
  gitOutput += chunk;
});

// Finished reading in git output
process.stdin.on('end', function () {
  branch = gitOutput.split(" ").pop().split("/").pop();
});