g++ -Os -fno-exceptions -fno-rtti -lfltk -o help help.cxx
/tmp/ccqFdqeD.o: In function `main':
help.cxx:(.text+0x29): undefined reference to `Fl_Help_Dialog::Fl_Help_Dialog()'
help.cxx:(.text+0x43): undefined reference to `Fl_Help_Dialog::load(char const*)'
help.cxx:(.text+0x4f): undefined reference to `Fl_Help_Dialog::show(int, char**)'
help.cxx:(.text+0x64): undefined reference to `Fl_Help_Dialog::~Fl_Help_Dialog()'