Chdir changes the current working directory to the named directory.

Chmod changes the mode of the named file to mode.

CopyFile copy src file to des file.

DirExists check if the directory dir exists return ErrIsNotDir if dir is not directory.

DirIsEmpty check if the directory dir contains sub folders or files.

FileExists check if the file exists return ErrIsDir if file is directory.

FileSize get the file size.

Mkdir creates a new directory with the specified name and permission bits (before umask).

MkdirAll creates a directory named path, along with any necessary parents, and returns nil, or else returns an error.

ReadDir reads the named directory, returning all its directory entries sorted by filename.

ReadFile reads the file named by filename and returns the contents.

ReadString reads the file named by filename and returns the contents as string.

Remove removes the named file or directory.

RemoveAll removes path and any children it contains.

Remove removes all files return the by filepath.Glob().

Remove removes all files and children return the by filepath.Glob().

WriteFile writes data to a file named by filename.

WriteReader writes reader data to a file named by filename.

WriteString writes string data to a file named by filename.

"file already closed".

"file already exists".

"invalid argument".

"file does not exist".

"permission denied".

A DirEntry is an entry read from a directory (using the ReadDir function or a File's ReadDir method).

A FileInfo describes a file and is returned by Stat and Lstat.

A FileMode represents a file's mode and permission bits.