# check the exit code
code=$?
if [ $code -eq 0 ]; then
    # Now you can use the deployment url from stdout for the next step of your workflow
    deploymentUrl=`cat deployment-url.txt`
    vercel alias $deploymentUrl my-custom-domain.com
else
    # Handle the error
    errorMessage=`cat error.txt`
    echo "There was an error: $errorMessage"
fi
```

## Standard error usage

If you need to check for errors when the command is executed such as in a CI/CD workflow,
use `stderr`. If the exit code is anything other than `0`, an error has occurred. The
following example demonstrates a script that checks if the exit code is not equal to 0:

```bash filename="checkDeploy.sh"