Lessons · Terminal · runs of spaces are not fields

When the columns are spaces

cut treats every delimiter as a boundary, so two spaces in a row mean an empty field between them.

Hone is a place to practise programming. This is one of its lessons, written out in full and free to read without an account.

What it is for

Command output is nearly always space-aligned, which is exactly the shape cut is bad at.

One consistent character: cut. Runs of whitespace: awk.

cut -d' ' -f2 spaced.txt

The second line gives 4; the first gives nothing, because field 2 is an empty gap.

awk '{print $2}' spaced.txt

awk splits on runs of whitespace, so $2 is the second COLUMN in both lines.

Print the second whitespace-separated column of app.log.

 '{print $2}' app.log

This is the one job cut genuinely cannot do. Reaching for a cleverer -d will not fix it.

Practise runs of spaces are not fields on HoneA question on it now, a coding challenge where there is one, and it is remembered for review. Free, no email needed.