This is a very specific bash script which gives quick line count results (similar to `wc -l`) by sampling the first few lines of a file (configurable) and dividing into the average of the reported file size. My need for this utility arose when dealing with multi-GB fixed-width data files.

It's worth noting that for fixed-width files, the results of qwc should be identical to "wc -l".

To run, simply run as you would wc -l:

$ qwc data.txt
2129950

$ qwc -l data.txt
2129950


The "-l" is optional, so you can perform an operation like this (using bash):

$ wc -l data2.txt
( taking too long, Ctrl+C)
$ q!! 
qwc -l data2.txt
9342447