As is often the case I needed to accomplish something, so I tinkered until I figure it out. I had a web site that I recently moved from a PHP 5.2 to 5.3 enabled server. It became a problem when I realized my error logs had filled up with 600 MB of deprecated function messages, and after fixing the issues I wanted to clear out the logs.
While there are a few methods of doing this, I wanted to keep it simple. Here is the command I used:
The greater than symbol is the command which pipes nothing to the file, thus clearing it. This cleared up the file quickly, and left the permissions and filename in place.