A Bash script for screen recording, daemon mode, and customizable frame rate and duration.

record.sh

#!/bin/bash

output_dir="$HOME/Videos/Replays"
rate=30
pipe_path="/tmp/record_control_pipe"
pid_file="/tmp/record_screen.pid"
daemon_pid_file="/tmp/record_screen_daemon.pid"
daemon_log_file="/tmp/record_screen_daemon.log"
record_extension="mp4"
timeout=60

usage() {
    echo "Usage: $0 [-r rate] [-d output_dir]"
    echo "    -r rate        Frames per second (default: $rate)"
    echo "    -t timeout     Set a time limit for recording (in seconds, default: $timeout)"
    echo "    -x             Toggle recording on or off"
    echo "    -D             Run script as a daemon"
    echo "    -k             Stop the daemonized script"
    echo "                   (only one of -D or -k options can be used)"
    echo "    -d output_dir  Directory to save recordings (default: $output_dir)"
    exit 1
}

action=''

while getopts "r:d:t:Dkxh" opt; do
    case ${opt} in
        r ) rate=$OPTARG ;;
        d ) output_dir=$OPTARG ;;
        t ) timeout=$OPTARG ;;
        x ) action='toggle_record' ;;
        D ) action='daemonize' ;;
        k ) action='kill_daemon' ;;
        h ) usage ;;
        * ) usage ;;
    esac
done

trap 'cleanup' SIGINT SIGTERM

cleanup() {
    if [ -e "$pipe_path" ]; then rm -f "$pipe_path"; fi
    if [ -f "$pid_file" ]; then
        kill -SIGINT $(cat "$pid_file")
        rm -f "$pid_file"
    fi
    pkill -P $$
    exit 0
}

send_notification() {
    local message=$1
    notify-send "Screen Recording" "$message"
}

start_recording() {
    mkdir -p "$output_dir"
    local filename="$output_dir/replay-$(date +'%Y-%m-%d_%H-%M-%S').$record_extension"
    ffmpeg \
        -video_size "3840x2160" \
        -framerate "$rate" \
        -f x11grab \
        -i :0.0+2160,840 \
        -f alsa \
        -i pulse \
        -vf "scale=1920:1080" \
        -draw_mouse 1 \
        "$filename" &
    echo $! > "$pid_file"
    send_notification "Recording started in $filename"
    ( sleep "$timeout" && [ -f "$pid_file" ] && toggle_recording ) &
}

stop_recording() {
    if [ -f "$pid_file" ]; then
        kill -SIGINT $(cat "$pid_file")
        rm -f "$pid_file"
        send_notification "Recording stopped"
    else
        echo "No recording in progress."
    fi
}

toggle_recording() {
    if [ -f "$pid_file" ]; then
        stop_recording
    else
        start_recording
    fi
}

stop_daemon() {
    if [ -f "$daemon_pid_file" ]; then
        echo "Stopping daemon process..."
        kill -SIGTERM $(cat "$daemon_pid_file")
        rm -f "$daemon_pid_file"
        exit 0
    else
        echo "No running daemon process found."
        exit 1
    fi
}

if [ "$action" == "kill_daemon" ]; then
    stop_daemon
fi

if [ "$action" == "daemonize" ]; then
    if [ -f "$daemon_pid_file" ]; then
        echo "Error: A daemon process is already running. Stop the daemon before running the script normally."
        exit 1
    fi

    nohup "$0" -r "$rate" -d "$output_dir" > $daemon_log_file 2>&1 &
    echo $! > "$daemon_pid_file"
    exit 0
fi

if [ "$action" == "toggle_record" ]; then
    if [ ! -p "$pipe_path" ]; then
        echo "Error: Cannot toggle recording; this script must first be running first without flags or the -D flag."
        exit 1
    fi
    echo "toggle_recording" > "$pipe_path"
    exit 0
fi

if [ ! -p "$pipe_path" ]; then
    if [ -e "$pipe_path" ]; then
        echo "Error: A non-pipe file exists at $pipe_path. Please remove or rename that file."
        exit 1
    fi
    mkfifo "$pipe_path"
fi

echo "Listening for recording commands..."

while true; do
    if read -r command <"$pipe_path"; then
        case $command in
            toggle_recording) toggle_recording ;;
            *) echo "Unrecognized command: $command" ;;
        esac
    fi
done