Why is this “can't break line” warning from grep of gcc man page?

Question

I was trying to find a line ending with -s with the following command but got warnings:

$ man gcc | grep \'\\-s$\'
:4808:          


        

Answer 1

Normally man formats the content to match the width of the terminal. You redirect it's output to a pipe, which has no "screen width", therefore it formats using the default width of 80 chars. Some man pages has tables that are more than 80 chars wide, so you get this "can't break line" warning. Try this:

$ MANWIDTH=160 man gcc | grep '\-s$'