creationix

// Implement bash string escaping.
var safePattern =    /^[a-z0-9_\/\-.,?:@#%^+=\[\]]*$/i;
var safeishPattern = /^[a-z0-9_\/\-.,?:@#%^+=\[\]{}|&()<>; *']*$/i;
function bashEscape(arg) {
  // These don't need quoting
  if (safePattern.test(arg)) return arg;

  // These are fine wrapped in double quotes using weak escaping.
  if (safeishPattern.test(arg)) return '"' + arg + '"';