How to Safely Create an Empty File Before Reading in Go?

Creating an Empty Text File for Safe File Reading

When working with files, encountering non-existent files can lead to unexpected errors. To prevent this, you can create a function that checks for file existence and creates an empty file if necessary. Here's how:

First, let's define a function to check if a file exists:

func exists(path string) (bool, error) {
    _, err := os.Stat(path)
    if err == nil {
        return true, nil
    }
    if os.IsNotExist(err) {
        return false, nil
    }
    return true, err
}

However, this approach suffers from a race condition. If the file is created concurrently, its check may return false, leading to incorrect behavior.

To overcome this issue, use os.OpenFile() with the O_CREATE flag instead of checking existence first:

func createEmptyFile(path string) (*os.File, error) {
    return os.OpenFile(path, os.O_RDONLY|os.O_CREATE, 0666)
}

Now, when calling createEmptyFile(), the file will be created if it doesn't exist, ensuring safe file reading.

The above is the detailed content of How to Safely Create an Empty File Before Reading in Go?. For more information, please follow other related articles on the PHP Chinese website!