How to limit re-execution of function

I have set a keyboard shortcut to call a bash script, but it turns out if I spam the shortcut, the program launched from within the script crashes.

Here's a reduced version of the script:

#!/bin/bash

# Config
monitor="eDP-1"
wallpaper_dir="$HOME/Pictures/bg"

# Get list of wallpaper file paths
file_listing=($wallpaper_dir/*)

function hyprpaper_set() {

    # Get one random file path
    file_random=("${file_listing[RANDOM % ${#file_listing[@]}]}")

    # Set wallpaper with hyprctl
    hyprctl hyprpaper wallpaper "$monitor,$file_random"

}

hyprpaper_set

What I would like to achieve is a limit to how often the hyprpaper_set function can be called, for example once per second, to avoid undesirable results.

I have tried comparing dates at different code sections with date +"%S"

I have tried using the SECONDS function and comparing how much time has elapsed

I have tried the export function to make variables available globally so that once the script is re-executed, comparative values can remain.

I can't figure this one, so any help is greatly appreciated. Thanks!

Edit:

A lock solution seems to work well. Modified script:

function hyprpaper_set() {

    # Set lock
    lockdir=/tmp/myscript.lock

    if mkdir -- "$lockdir"; then

        # Get one random file path
        file_random=("${file_listing[RANDOM % ${#file_listing[@]}]}")
       
        # Set wallpaper with hyprctl
        hyprctl hyprpaper wallpaper "$monitor,$file_random"

        # Remove lockdir when the script finishes, or when it receives a signal
        trap 'rm -rf -- "$lockdir"' 0    # remove directory when script finishes

    else

        printf >&2 'cannot acquire lock, giving up on %s\n' "$lockdir"
        exit 0

    fi

}

hyprpaper_set

You could achieve this by storing the timestamp of the last script run in a file and then comparing the current timestamp with the saved one each time the script runs.

Here's your script modified to add this functionality:

#!/bin/bash

# Config
monitor="eDP-1"
wallpaper_dir="$HOME/Pictures/bg"
time_stamp_file="$HOME/.last_hyprpaper_run"

# Get list of wallpaper file paths
file_listing=($wallpaper_dir/*)

function hyprpaper_set() {
    # Get one random file path
    file_random=("${file_listing[RANDOM % ${#file_listing[@]}]}")

    # Set wallpaper with hyprctl
    hyprctl hyprpaper wallpaper "$monitor,$file_random"
}

# Check if the script was run less than a second ago
if [ -f "$time_stamp_file" ]; then
    last_run=$(cat "$time_stamp_file")
    current_time=$(date +%s)
    time_diff=$((current_time - last_run))

    if [ "$time_diff" -lt "1" ]; then
        echo "Please wait a second before running the script again."
        exit 1
    fi
fi

# Save the current timestamp
date +%s > "$time_stamp_file"

# Call the function
hyprpaper_set