How to read the second-to-last line in a file using Bash?

A short sed one-liner inspired by https://stackoverflow.com/a/7671772/5287901

sed -n 'x;$p'

Explanation:

• -n quiet mode: dont automatically print the pattern space
• x: exchange the pattern space and the hold space (hold space now store the current line, and pattern space the previous line, if any)
• $: on the last line, p: print the pattern space (the previous line, which in this case is the penultimate line).

Try this:

tail -2 yourfile | head -1