Faking watch on OS X

Sometimes watching something change over time in your terminal is kinda helpful. Linux has a great utility for this called "watch". OS X doesn't some with this. Of course you can build it yourself if you want .. but that can mean a chunk of pain too... luckily bash comes with what you need. "while" and some ANSII escape sequences are enough to get you going.

Here was my first try:

The first problem with this for me was that in iterm2 clear just keeps adding to your terminal scrollback in some weird way. Luckily replacing this with some ANSII control sequences fixes that up nicely.

Now it doesn't add to the scrollback but it does blink every 4 second. I fixed this by storing the current and previous results in temp files and only clearing if they've changed.

Examining multiple cores with gdb and grep

So you've got a bunch of core files from a failing application. You look in one of them and find what's causing that particular error. However you're not sure whether all the cores are caused by the one same issue.

The application I was having trouble with was a multithreaded app, so I couldn't rely on the stacs being identical every time... so this is what I did.

stackdumper.gdb Then in bash:

In my case I found that string in all 80 cores, so I know that was the only issue.