dynamically change the lambda layer version number using a shell executable

You can simply parse the response from the first command:

For example, I’m using here jq, which parses jsons in bash.

version=$(aws lambda publish-layer-version --layer-name <your name> --zip-file <zip> --region "us-east-1" | jq -r '.LayerVersionArn')

Then, you can upload with: aws lambda update-function-configuration --function-name <name> --layers $version

Disclosure: I work for Lumigo, a company that provides serverless monitoring.