Cook

Modifications

• ! before the flag to check opposite
  • ex. if [ ! -f "$FILE" ] checks that file does NOT exist

---

Check if a CLI package is installed

if ! aws_bin="$(which aws)" 2>/dev/null; then
    echo "aws cli is missing; you can get it from https://aws.amazon.com/cli/"
    exit 1
fi

Variation: install package if it's not found

[ $(which ts-node) ] || echo "ts-node not found. Installing..." && npm i -g ts-node

Check if environment variable set

if [ -z $APP_NAME ]; then echo "Error:'APP_NAME' is not set, it is required for serverless" && exit 1; fi

Check if X exists

• file - -f
• directory - -d

if [ -d "$FILE" ]; then
    echo "$FILE is a directory."
fi

One liner: [ -d /etc/docker ] && echo "$FILE is a directory."