File buffer functions are used to create and manipulate file buffers and the text within them. A file buffer is the loaded image of a text file. File buffers are edited by the user and then saved back to disk with the Save command.
Many of the file buffer functions use buffer handles (hbuf). These are handles to open file buffers. An hbuf is typically a small integer value. An hbuf value of hNil (zero) indicates an error.