gtk-text-buffer-get-text (buffer start end include-hidden-chars)
An allocated UTF-8 string.
Returns the text in the range [start, end). Excludes undisplayed text, text marked with tags that set the invisibility attribute, if include-hidden-chars is nil. Does not include characters representing embedded images, so byte and character indexes into the returned string do not correspond to byte and character indexes into the buffer. Contrast with the function gtk-text-buffer-get-slice.