After changing working directory print directory listing if terminal is big enough to fit it, otherwise print $MOST_RECENT_LEN recently modified entries.

zshrc function chpwd

MOST_RECENT_LEN=20
function chpwd {
    if [[ $(ls --format=vertical -w ${COLUMNS} | wc -l) -lt $((LINES - 1)) ]] {
       ls
    } else {
        echo $(find . -maxdepth 1 | wc -l) entries. \
            Showing $MOST_RECENT_LEN most recent \(ctime\)
        ls -c | head -n$MOST_RECENT_LEN
    }
}