I've had occasion to need to grab a specific set of files from a large directory — most recently, I needed to grab some specific access logs from our Apache logfiles at work.

Enter find.

I needed to get all files newer than a specific date, and with the pattern 'sitename-access_log.timestamp.gz'. I then needed to tar up these files and grab them for processing. So, here's what I did:

• The -newer filename tells find to locate files newer than filename.
• The -regex flag tells find to locate files matching the regular expression. The regex that find uses is a little strange, however, and didn't follow many conventions I know; for one thing, it's assumed that the pattern you write will match against the entire string, and not just a portion of it. What I ended up using was -regex '.*access_log.*gz', and that worked.
• The -printf flag tells find to format the printing. This is useful when using the output of find in another program. For instance, tar likes a list of filenames… so I used -printf "%p ", which separated each filename with a space.

I then backticked my full find statement and used it as the final argument to a tar command; voila! instant tar file with the files I need!