Topic Why is this pipe terminated? explains, why a pipe may prematurely be closed by 'head':
find / | head
So why is the following pipe not closed by 'head'?
find / -exec zgrep -l 'a' {} \; | head
using grep instead of zgrep produces lots of
find: "grep" terminated by signal 13
warnings, but the the pipe nevertheless stays active. Is there any way to prematurly stop 'find' in combination with 'grep'?