Squeak's file libraries (Directory, DirectoryEntry, FileStream, etc.) are sometimes very confusing to use. FileMan provides a simple, refactored interfaces for manipulating files and directories by wrapping those classes.
"Before" subDir := FileDirectory default directoryNamed: 'subDir'. subDir assureExistence. [str := subDir newFileNamed: 'file1'. str nextPutAll: 'Hello!'] ensure: [str close].
"After installation of FileMan" './subDir' asDirectoryEntry at: 'file2' put: 'Hello!'