When parsing API endpoint URLs, implement rigorous input validation using precise regular expressions. This includes:

For example, instead of:

[[ "${API_URL}" =~ https://(([^:@]+)(:([^@]+))?@)?github.com/(.*)$ ]]

Use a more precise pattern:

[[ "${API_URL}" =~ https://(([^:@/?#]+)(:([^@/?#]+))?@)?github\.com/(.*)$ ]]

For API keys or tokens, consider restricting to known valid formats:

[[ "${API_TOKEN}" =~ ^[[:alnum:]_]+$ ]]

This approach prevents security vulnerabilities and ensures consistent API authentication handling across your application.