Script for macOS that automates desktop screenshots and video capture

#!/bin/bash
# script to run screencapture

screenshot="$(which screencapture) -x -m -C"
freq=30     #take a screenshot every 30 seconds
maxshots=45 #take 45 screenshots then quit

while getopts "af:m" opt; do
    case $opt in
    f ) freq=$OPTARG;       ;;
    m ) maxshots=$OPTARG;   ;;
    ? ) echo "Usage: $0 [-f frequency] [-m maxcaps]" >&2
        exit 1
    esac
done

#set startng number; incrementally append to filename
counter=1

while [ $counter -lt $maxshots ] ; do
    $screenshot screenshot${counter}.jpg
    counter=$(( counter + 1 ))
    sleep $freq
done

exit

chmod +x screencap.sh
./screencap.sh
./screencap.sh -f 8