getChars
Retrieves a sequence of characters.
The characters that are retrieved are those characters at positions from @start_pos up to, but not including @end_pos. If @end_pos is negative, then the characters retrieved are those characters from @start_pos to the end of the text.
Note that positions are specified in characters, not bytes.
Return
a pointer to the contents of the widget as a string. This string is allocated by the GtkEditable implementation and should be freed by the caller.
Parameters
startPos
start of text
endPos
end of text