flex template, without token returning

build.bat

flex lexer.l
gcc lex.yy.c
a.exe

lexer.flex

%{
  extern int yylex();
%}
%option noyywrap

WS			[ \t\n]+
ID    		[a-z]
S1      	"."{ID}+
S2    		{ID}+.
T_DEF		"def"


%%

{T_DEF} 		{printf("DEF  found\n");}
{S1} 			{printf("s1 : %s\n",yytext);}
{S2} 			{printf("s2 : %s\n",yytext);}


%%
int main(int argc, char** argv) {
  while (yylex());
}