ncp - Asynchronous recursive file & directory copying

Think cp -r, but pure node, and asynchronous. ncp can be used both as a CLI tool and programmatically.

Command Line usage

Usage is simple: ncp [source] [dest] [--limit=concurrency limit] [--filter=filter] --stopOnErr

The 'filter' is a Regular Expression - matched files will be copied.

The 'concurrency limit' is an integer that represents how many pending file system requests ncp has at a time.

'stoponerr' is a boolean flag that will tell ncp to stop immediately if any
errors arise, rather than attempting to continue while logging errors. The default behavior is to complete as many copies as possible, logging errors along the way.

If there are no errors, ncp will output done. when complete. If there are errors, the error messages will be logged to stdout and to ./ncp-debug.log, and the copy operation will attempt to continue.

Programmatic usage

Programmatic usage of ncp is just as simple. The only argument to the completion callback is a possible error.

 var ncp = require('ncp').ncp;

ncp.limit = 16;

ncp(source, destination, function (err) {
 if (err) {
   return console.error(err);
 }
 console.log('done!');
});

You can also call ncp like ncp(source, destination, options, callback).
options should be a dictionary. Currently, such options are available:

• options.filter - a RegExp instance, against which each file name is
  tested to determine whether to copy it or not, or a function taking single
  parameter: copied file name, returning true or false, determining
  whether to copy file or not.

• options.transform - a function: function (read, write) { read.pipe(write) }
  used to apply streaming transforms while copying.

• options.clobber - boolean=true. if set to false, ncp will not overwrite
  destination files that already exist.

• options.dereference - boolean=false. If set to true, ncp will follow symbolic
  links. For example, a symlink in the source tree pointing to a regular file
  will become a regular file in the destination tree. Broken symlinks will result in
  errors.

• options.stopOnErr - boolean=false. If set to true, ncp will behave like cp -r,
  and stop on the first error it encounters. By default, ncp continues copying, logging all
  errors and returning an array.

• options.errs - stream. If options.stopOnErr is false, a stream can be provided, and errors will be written to this stream.

Please open an issue if any bugs arise. As always, I accept (working) pull requests, and refunds are available at /dev/null.