A collection of small bash utils.

• smash-overlay
• backup-hdd
• screen-timelapse
• folder-size

Do something to every file in a folder:

#!/bin/bash
for filename in *; do
    echo "$filename"
done

Do something every 5s:

#!/bin/bash
while sleep 5
do    
    echo "yo"
done

Ask for parameters:

#!/bin/bash
read -p "Do it? (y/n) " doit

if [[ $doit == "y" || $doit == "Y" ]]; then
	echo "Do it"
else
	exit
fi

Use the clipboard:

# Print clipboard content to text file
pbpaste > file.txt

Get today's date (YYYY-MM-DD):

DATE=`date  %Y-%m-%d`

Ping an API:

Here, a simple script outputs the contrast ratio of white on a color. We use webaim.org’s API, and pipe the output into jq to read a value out of the resulting json. xargs echo -n can allow to strip whitespace after the result.

COLOR="$1"
curl -s https://webaim.org/resources/contrastchecker/\?fcolor\=FFFFFF\&bcolor\="$1"\&api | jq -r '.ratio'

Display a notification:

osascript -e 'display notification "Lorem ipsum dolor sit amet" with title "Title"'

To use a script as an executable, change the extension to .command. This will start the script from /, though, so you might want to tell it to navigate to where the script is located before doing anything. Add cd "$(dirname "$0")" at the top of the script to do so. You'll also have to chmod 777 name_of_your_script.command to be able to execute it.

To use a script from anywhere, add it to /usr/local/bin/.

Command substitution allows to replace a command with its output, e.g. $(pwd) gives the value of pwd.

• Add utils for imagemagick
• Add utils for ffmpeg

• Script as a service (macOS)
• "Daemons" & init scripts
• Scripts in Alfred