Wonderful Unix Number Counting Command
Today I was having a really bad day with my UDP feed recorders. They filled up a 3TB+ drive array and I could not figure out why. As I dug into this, I starting seeing a pattern that was really bad: the files in a directory didn't add up to the output of du. So I wanted to test the theory.
The trick was, I wanted to just run a simple command - not write a script or a program. Just a command, but it wasn't clear what to do. So I hit google, and there was the simple result:
ls -lsa | awk '{ sum += $6 }END{ print sum }'
The ls is obvious - the 6th column is the number of bytes, but the awk line is the real beauty here. I've used awk a lot before, but I didn't know it had dynamic variables like this. And then to have the END tag to put it at the end of the command. Simply brilliant.
This is why I love linux/unix. You don't have to write groovy scripts if you understand the system. Love it!