How it works...

If you're familiar with files in Unix, the Go os library should feel very familiar. You can do basically all common operations--stat a file to collect attributes, collect a file with different permissions, and create and modify directories and files. We performed a number of manipulations to directories and files and then cleaned up after ourselves.

Working with file objects is very similar to in-memory streams. Files also provide a number of convenience functions directly, such as Chown, Stat, and Truncate. The easiest way to get comfortable with files is to make use of them. In all the previous recipes, we have to be careful to clean up after our programs.

Working with files is a very common operation when building backend applications. Files can be used for configuration, secret keys, as temporary storage, and more. Go wraps OS system calls using the os package and allows the same functions to operate regardless of whether you're using Windows or Unix.

Once your file is opened and stored in a File struct, it can easily be passed into a number of interfaces discussed earlier. All the earlier examples of working with buffers and in-memory data streams can be replaced directly with file objects. This may be useful for things such as writing all logs to stderr and the file at the same time with a single write call.