CopyFile copies from src to dst until either EOF is reached on src or an error occurs.

CreateIfNotExists creates a file or a directory only if it does not already exist.

IsDir reports whether this path is a directory.

IsDirE returns an error as whether this path is a directory.

IsExist reports whether this path exist.

IsExistE returns whether this path exist and error.

Lock places an advisory write lock on the file, When the immediately is false, it will block until the lock can be locked, otherwise an error will be returned immediately.

ReadLineBytesFunc read the file line by line and call f(c) to process each line of bytes.

ReadLineFunc read the file line by line and call f(c) to process each line of string.

RLock places an advisory read lock on the file, When the immediately is false, it will block until the lock can be locked, otherwise an error will be returned immediately.

Unlock removes an advisory lock placed on f by this process.