identifier.l

letter          [A-Za-z]
digit           [0-9]

%{
    #include <stdio.h>
%}

%%

    /*An identifier starts with a letter followed by 0 or more letters or digits*/

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

%%

int yywrap() {
    return 1;
}


int main()
{
    yylex();
}