So I was messing around with getting a few logging systems setup for a web app I’m writing and after a while these log files started to grow in size to the point that it was difficult to find the relevant data quickly. I needed a quick way to empty a file without deleting it. Here’s the trick I learned:
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// First let's put some text into a file $ echo "test" > filename.log // Let's display it $ cat filename.log // and empty it $ cat /dev/null > filename.log |
Basically ‘cat’ reads the file contents of whatever you specify, in this case /dev/null which is empty. It then uses the ‘>’ character to push the contents of /dev/null (empty) to filename.log, overwriting anything that currently exists in it.
An even quicker way to clear a file:
$ > filename.log
😉 Just thought I’d share.