Often I have a bunch of numbers (like transfer sizes from an httpd log file) and I want to get the average in a shell script, without pasting into an excel sheet.
Here's one way to do it. In this example, I want to calculate the average size of a cgi output. In my apache log format, column 7 is the transferred size in bytes.
grep 'GET /some_url.cgi' access_log | cut -f7 | awk '{total += $1;count += 1;printf"avg = %d\n", total/count}' | tail -1
