Turn on or off line drawing characters
void SLsmg_set_char_set (int a);
SLsmg_set_char_set may be used to select or deselect the line drawing
character set as the current character set. If a is non-zero,
the line drawing character set will be selected. Otherwise, the
standard character set will be selected.
There is no guarantee that this function will actually enable the use of line drawing characters. All it does is cause subsequent characters to be rendered using the terminal's alternate character set. Such character sets usually contain line drawing characters.
SLsmg_write_char, SLtt_get_terminfo