Glob returns the names of all files matching pattern or nil if there is no matching file.

ReadFile reads the named file and returns the contents from the given filesystem.

RemoveAll removes path and any children it contains.

TempDir creates a new temporary directory in the directory dir with a name beginning with prefix and returns the path of the new directory.

TempFile creates a new temporary file in the directory dir with a name beginning with prefix, opens the file for reading and writing, and returns the resulting *os.File.

Walk walks the file tree rooted at root, calling fn for each file or directory in the tree, including root.

WriteFile writes data to a file named by filename in the given filesystem.