How to handle I/O errors and perform error checking in Go?

In Go, handling I/O errors and performing error checking is quite straightforward. Here are some tips to handle I/O errors effectively:

Utilize multiple return values: Most I/O functions in Go return multiple values, including the result and an error. Always assign these return values and check the error value.

result, err := SomeIOFunction()
if err != nil {
    // handle the error
}

Check for specific errors: Instead of solely checking if err is not nil, it's better to handle specific types of errors. For instance, you can use the os.IsNotExist function to identify a "file not found" error.

if os.IsNotExist(err) {
    // handle file not found error
} else if err != nil {
    // handle general error
}

Use error wrapping and contextual information: You can provide additional information about the error by wrapping it using the fmt.Errorf function. This helps to track where the error originated.

return fmt.Errorf("reading file: %w", err)

Handle different types of I/O errors: I/O errors can vary, such as read, write, or permission errors. Identify and handle them accordingly based on the specific I/O operation you're performing.
Retry operations or provide fallbacks: In certain scenarios, you can retry the I/O operation if it fails initially. You can implement a retry mechanism with a limited number of retries and a delay between each attempt. Additionally, you may provide a fallback mechanism or alternative paths to handle I/O failures gracefully.
Log or report errors: Logging I/O errors, along with helpful information, can aid in debugging and troubleshooting. Log the error message or relevant details about the failed I/O operation.

log.Printf("failed to read file: %s", err)

By following these best practices, you can effectively handle I/O errors and perform error checking in your Go applications.