Inspirou-se no AFH para usar esta solução
zipinfo -1 archive.zip |
egrep '^[^/]+/?$' |
egrep -v '__MACOSX' |
wc -l |
awk '{$1=$1};1'
O que faz:
Get list of files in archive
Filter for top-level files or dirs; must either contain no '/' or end in '/'
Remove lines containing __MACOSX (for archives created on a Mac)
Get line count
Remove trailing whitespace; http://unix.stackexchange.com/a/205854/169465