Does calling fs.writeFileSync trigger a synchronous write to the file system?

If you are familiar with Node.js, or have at least heard of it, you’ve most likely heard that it uses non-blocking IO, and lets you do work asynchronously. One of the most basic APIs that Node provides is for the file system; With this API, you can read, write, remove, etc. files and do other file system related tasks and modifications.

This API follows a standard pattern of exposing 2 functions for each operation: one for asynchronous work, and the other for synchronous work. For example, if you want to read a file in Node you can do so asynchronously:

var fs = require('fs');
fs.readFile('/etc/passwd', function(err, buf) {
  console.log(buf.toString());
});

Node will continue executing any javascript code it encounters while reading the file. Once all javascript is done being executed and the file is ready, it will run the anonymous function and print the file contents.

Read More...

I wrote 2 blog posts for the Voxer Engineering Blog. The first post talks about migrating from Hosted Chef to a private, self-hosted Chef instance. The second goes over performance analysis of Chef, and getting it to run 16x faster!

• Chef Part 1 - Migration
• Chef Part 2 - Performance

A command line interface to phillips hue

I wrote a command line tool to interface with hue lights. Check out the project page for more information

https://github.com/bahamas10/hue-cli

Installation

First, install Node.js, then:

npm install -g hue-cli

…and the executable will be installed globally as hue

Read More...

Unfreeze a frozen Photoshop on Mac

I wrote an app to unfreeze a stuck or frozen photoshop. If you’re running photoshop, and it starts beachballing, or not responding on you, try running this. This application will help if suddenly you have a frozen photoshop, and you want to fix it.

Download the app

Read more about it here

Buffer calls to console.log, console.warn, etc. for high performance logging

Description

Calls to console.log, console.error, etc. are synchronous, and as such, will block the event loop while the data is being written to a file, terminal, socket, pipe, etc.

This module provides a seamless, drop-in buffer for all calls to these functions, and flushes them when the buffers exceed a certain size (8k by default).

See Known Issues for timing concerns with this module.

View the project on GitHub

Read More...

Concurrently curl a list of hosts and print the results

View the project page on GitHub

Usage

Used as a command line tool

pcurl url1 url2 url3 ...

or pipe through stdin

pcurl < newline_sep_list_of_urls.txt

Read More...

Convert Unix style permissions to strings like ls (0755 => ‘rwxr-xr-x’)

I wrote this module to make it easy to print out nice looking permissions in my scripts before calling fs.chmod for the user.

Examples

Given

var perms = require('perms');

Convert a mode to a human-readable string like ls(1) generates

var p = perms.toString('0755');
console.log(p);

yields

rwxr-xr-x

Read More...

watch - execute a program periodically, showing output fullscreen

Coming from Linux, I have become used to the watch tool. The program is very simple, it lets you run a command at a given interval, and update the terminal with the output. It’s like a simple while loop that runs a command, but it uses ncurses to update the view, which makes it easy to spot differences.

Compiling it on SmartOS was straight forward, the hardest part was finding the source of watch(1). It turns out it is bundled with a handful of tools for dealing with the Linux proc filesystem. Because of this, most of the tools wont compile (or be useful) on an Illumos based operating system, so the Makefile proved to not be helpful.

Read More...

I was working on my latest module for node, latest, when I encountered a problem. While testing, I noticed output being written to the terminal that I wasn’t generating. This means that some module had the audacity to write directly to the terminal… bad.

My project was only including the npm module, however the npm module included its own handful of other modules, and they included their own modules, and so-on. If I were to look through the source myself to try and find what was outputting to the terminal it would have taken forever, trying to trace what function was calling what. Instead, I decided to override the stdout streams write function, to stack trace when invoked. This means that any function that writes to stdout will cause a stack trace to be printed to the screen.

Read More...

Call a child process with the ease of exec and safety of spawn

View the Project page on GitHub

Why?

This module provides the best of both worlds of spawn and exec

It will simply return 2 strings containing stdout and stderr (like child_process.exec), but will take an array of process arguments (like child_process.spawn) to avoid any nasty shell expansion.

Read More...