int read_file(char * filename)
Changes the current buffer to the file associated to
filename like the Read File menu entry, except that
if the current buffer is not saved, its contents is lost (see
current_buffer_is_modified()
§7.3.8 page ). Returns 0 if there is no
file matching filename and
-1
if the file is
already loaded in an other buffer of the current session,
leaving the buffer unchanged. Otherwise returns 1 and loads
filename in the current buffer.
The current position becomes the beginning of buffer.