I previously used an answer from another post that shows how to get a list of the linker paths on a system, ldconfig -v 2>/dev/null | grep -v ^$'\t'.
What I don't get is how the regex makes sense. The ^$ should match empty lines, so how does the trailing '\t' even get checked?
Your first assumption is off:
^ is interpreted as beginning-of-line.$ is treated as part of a shell expansion that forms $'\t'. This is to escape a character literal in the shell. The same approach is used when changing the internal field separator (IFS).In short, the regex evaluates to "exclude lines that begin with hard-tabs".
