Ever needed to see more context surrounding your NSLog statement to help you debug in the console? Me too. In fact, some people have written entire classes and kindly shared them with us on the internet. Personally, I don't think an entire class is necessary for this simple task, so I wrote a single preprocessor macro for the job. Here you go!
@"\n-------------\nBetter Log\n%s:%d\n%@\n[%s]\n\n[%@]\n-------------\n",\ strrchr(__FILE__, '/'), __LINE__, self, sel_getName(_cmd),\ [NSString stringWithFormat:str ,(
Let's break it down for a second and see what it's doing:
Firstly, you'll notice a lot of newlines and pseudo-separators inside the constant string; that's just to make it easier for me to read all the info at a quick glance. Feel free to change the format to fit your style better, it's fairly straightforward.
Next you see
strrchr(__FILE__, '/') which takes the current file that the log statement is being executed in, and returns a char* of the last file component. Notice that
__FILE__ is a special symbol used by our compiler to allow us to know what file we're currently in, via a handy C string. Sure, we could turn it into an NSString and use -lastPathComponent, but this is just as good (for me anyway).
After this is self, which is self-explanatory. After self, however, is
sel_getName(_cmd) which gets a handle on the SEL (selector) of the currently-executing method, and turns it into a C string as well.
Lastly, you'll notice
[NSString stringWithFormat:str , ## args ] which is the exact original string that would have been printed out had you simply used
When it's used with @"Hello World" inside my method -performAction:, this is what the output looks like:
------------- Better Log /SDAccountController.m:97 <SDAccountController: 0x2a4c30> [performAction:] [Hello world] -------------
So, hopefully someone will find good use for this, and maybe you've even learned a thing or two today that will help you in your future endeavors. Hoorah!
Thanks to a source who shall remain anonymous, this function was improved to work in functions as well as methods. Thanks tomasf!
NSLog(@"\n-------------\nBetter Log\n%s:%d\n%s\n\n[%@]\n-------------\n",\ strrchr(__FILE__, '/'), __LINE__, __PRETTY_FUNCTION__,\ [NSString stringWithFormat:str ,
This replaces both self and SEL and instead will print out
-[SDAccountController performAction:] which is just as informative, but sexier. Here's the full output after this addition:
------------- Better Log /SDAccountController.m:133 -[SDAccountController performAction:] [foo] -------------
My name is Steven Degutis, and I've been writing software professionally for a decade. During that time, I've written many apps and websites, quite a few technical articles, and kept up-to-date with the rapidly evolving software industry.
If you have software needs for web, mobile, or desktop, and are looking for a seasoned software professional, please reach out to me at email@example.com to set up a phone call.
- Self-employed – present
- Clean Coders – 5 years
- 8th Light – 2 years
- Big Nerd Ranch – 1 year
- Self-employed - 1 year
- Web: full-stack
- iOS (UIKit)
- macOS (Cocoa)
- REST APIs
- AWS / EC2 / ELB
- HTML5 / CSS
Over the past decade, I've written a total of 169 technical articles on various programming languages, frameworks, best practices, and my own projects, as I kept up-to-date and active in the software industry.
Subscribe via RSS / Atom.
- 2017 — "Clean code" isn't actually clean
- 2017 — Passion in your field is overrated
- 2017 — What I learned in 5 days of writing an experimental website
- 2014 — Age of the Polyglot
- 2013 — How to Program
- 2013 — Ignore the Naysayers
- 2013 — Writing Clearly
- 2012 — Reinvent the wheel
- 2010 — Good usability
- 2009 — Twitter is the wrong tool
- 2009 — We're all pretty bad at driving
- 2008 — Why I Code
|March||Notes on Haskell Extensions|
|February||Second thoughts on front-end tools|
|February||First thoughts on front-end tools|
|February||Some thoughts on GUIs|
|February||First thoughts on OCaml|
|February||First thoughts on Haskell|
Here are some of the projects I'm most proud of. They were created using a variety of technologies, running on several different platforms and OSes. They're all finished products, and many of them are open source.
I made Docks in 2009 for users who wanted to swap out icons in their Dock with a single click. Its unique functionality and design aesthetic attracted the attention of Apple, Engadget, MacWorld, and led to an acquisition of my start-up by Big Nerd Ranch.
This toy was made in a weekend to entertain my 1 year old daughter. It lets you create bubbles with your fingers, which then simulate physics by bumping into each other and falling.
When I couldn't find an app in the App Store that let me make very simple lists extremely quickly, I made one myself. I use it almost every day to organize and track my activities.
I created this app to increase my productivity by letting me move windows around in macOS using keyboard shortcuts. It grew into a community-driven highly extensible app, using Lua for its plugin system.
Implementing this elite social network gave me experience integrating both Apple Pay and credit card payments (via Stripe.com) seamlessly into web apps, for a frictionless and pain-free payment experience.
This isn't just any chatroom. In this web app, you can see what everyone is typing while they type it. I made this in order to scratch my itch for making real-time apps and games, and learned how to use WebSockets in the process.
This was written in 2009, before the time of Slack, when IRC was the main way for programmers to get short-term assistance from each other. Its purpose was to be a beautiful app with an emphasis on simplicity and usability over technical power.
This is an app I actually use every single day. It lets you move windows with global keyboard shortcuts. Since it uses Vim-like key bindings, it should feel pretty natural to any programmer. There's no configuration needed; it Just Works™.
As an evolution of Phoenix, Hydra was my first attempt at embedding a full Lua virtual machine into an Objective-C app, to make a lightweight and efficient window manager that focused on speed, low memory usage, low CPU usage, and overall being gentle on laptop batteries.
These may be tiny, but they're interesting technical feats.
|Lua4Swift||Swift framework for embedding Lua with a native Swift API.|
|choose||Command line fuzzy-matching tool for macOS that uses a GUI|
|music||Command line music daemon for macOS that only speaks JSON|
|hecto||Command line text editor with an embedded Lua plugin system|
|ZephSharp||Window manager for Windows using Clojure for scripting|
|management||Minimalist EC2 configuration & deployment tool in Ruby.|
|go.assert||Assertion helper package for writing tests in Go.|
|go.shattr||Go library for printing shell-attributed strings to stdout.|
|OCDSpec2||Objective-C based testing framework with Xcode integration.|