In my job in VFX we are dealing with sequences of files constantly, and sometimes being able to do things to parts of the frame range is extremely helpful, and awk is great for that!

Let's say U wanted to delete exr files named like filename.1055.exr where the frame number is not between 1001 and 1100, that could look like this:

ls -1 *.exr | awk -F "." '{if($2 < 1001 || $2 > 1100) print "rm -v "$0}'

This actually just prints the commands out which is nice to check that it looks reasonable, then one can redirect that back to the shell by adding "|sh" to the end to actually run them!

The -F "." bit sets the field separator to dot, so that $2 is the frame-number part of the filename.

This is just the tip of the iceberg! Once you're over the initial learning-hump, there's so much U can do with awk! Great stuff!