comments.l

letter          [a-zA-Z]
digit           [0-9]

%{
    #include <stdio.h>
%}

%x comment

%%

"/*"                            {BEGIN(comment); printf("Comment started\n");}
<comment>[^*]*                  { }
<comment>"*"+[^*/]*             { }
<comment>"*"+"/"                {BEGIN(INITIAL); printf("Comment Ended\n");}

{letter}({letter}|{digit})*     {printf("identifier scanned: %s\n", yytext);}

[ \t\n]+                       { }
.                              { }

%%

int yywrap() {
    return 1;
}

int main()
{
    yylex();
}