Posts tagged with: osx

Simulating Slow Connections in OS X or Linux

Simulating Slow and Laggy Connections


Do you want to simulate how it feels to load your site from a mobile connection (If it’s AT&T just turn off your network for an accurate simulation- I kid, don’t sue. But seriously AT&T, figure it out.) or from a laggy network? In OS X or Linux, you’ve got everything you need already installed: ipfw (IP firewall and traffic shaper control).

Create a Pipe

Configure a pipe with the appropriate bandwidth (I’ve also added a 200 ms response delay in this example).

Attach the Pipe

In this example we’re going to use port 80, but you can also use port 443 or any other port that you may be testing communication on. Additionally, you can attach the pipe to multiple ports.

That’s it!

Wait a second, you say! Now your network connection is completely throttled and everything is running terribly! You need to delete both ipfw entries and the pipe that were previously created.

Here’s how you undo what you’ve just done:

Encrypting a tar or gz (gzip) File with OpenSSL

When you have sensitive data that you need to transmit but want to make it easy to encrypt and decrypt it, use some standard tools to get the job done!

I recently had an issue where a client was using OS X laptops running an Admin panel written in PHP on MAMP in an environment that may or may not have an internet connection. The problem was that they needed to be able to dump their database data into an encrypted file so that they could send the data off when they get a connection (via email, upload, who knows). My initial response was to use gpg to encrypt the file and hand out the keys to the people who would eventually be reading the data.

Turns out, this was going to be a nightmare and I needed something ‘easier’. How about encrypting a tar file with OpenSSL? Bingo! This solution uses utilities that are already on the machine and no installations need to be performed. The reason this was such a big deal is because the laptops running this software will be all over the world with various levels of technical acumen and it will be a nightmare to make sure every single laptop has been updated correctly.

Encrypting Your File

tar and gzip the file, then encrypt it using des3 and a secret key.

That simple!

Decrypting Your File

Essentially, just call all the commands in the reverse order.

Download the Utility Scripts

Download them!

Quickly Clean Up .svn Directories Recursively

Did you forget to export your subversion project before copying it? Inheriting a subversion mess? Here’s how you clean it up real quick on Mac and Linux:
Change to the root of your target project/directory