Fortune + Cowsay with random cows

what.sh

#!/bin/bash

# First install fortune and cowsay:
# see http://manpages.ubuntu.com/manpages/bionic/en/man6/cowsay.6.html
# and http://manpages.ubuntu.com/manpages/bionic/man6/fortune.6.html
#   $ sudo apt-get install fortune cowsay
# and some collection of fortunes. You can find available packages:
#   $ apt search fortunes
# for example:
#   $ sudo apt-get install fortunes fortunes-off fortunes-ru
# now run what.sh

COWS=/usr/share/cowsay/cows
cows=""
for cow in $(ls -1 $COWS/*); do
    cows="$cows $(basename $cow    | sed 's/.cow$//')"
done
cows=($cows)
num_cows=${#cows[*]}
cow="${cows[$(( RANDOM % num_cows))]}"
fortune | cowsay -f $cow