13.7.3 Flex – a better Lex
flex is a fast lexical analyzer generator.
info flex (tutorial)
You need to provide your own
program.l should look like this to compile without a library
yywrap is a macro; %option main turns on
%option noyywrap implicitly):
.|\n ECHO ;
Alternatively, you may compile with the -lfl linker option at the
end of your
cc command line (like AT&T-Lex with
-ll). No %option is needed in this case.