%{
#include <stdio.h>

#define TK_IDENTIFIER 1
#define LIT_INTEGER 2
#define TK_OPERATOR_STAR 3
#define KW_INT  5

int LineNumber = 1;

%}

%x          COMM 

CHAR        [A-Za-z_]
DIGIT       [0-9]

%%

int                       { return KW_INT; }
{CHAR}({CHAR}|{DIGIT})*		{ return TK_IDENTIFIER; }
{DIGIT}+                  { return LIT_INTEGER; }
"*"                       { return TK_OPERATOR_STAR; }
"/*"                      BEGIN(COMM);
\n                  { ++LineNumber; }
[ \t]                     {  }
.

<COMM>"*/"                BEGIN(INITIAL);
<COMM>.

%%

int running = 1;

int main (int argc, char **argv)
  {
  int token = 0;
  
  if (argc < 2)
    {
    fprintf(stderr,"Please, call: ./a.out filename\n");
    exit(1);
    }
    
  yyin = fopen(argv[1],"r");
  if (yyin ==0)
    {
    fprintf(stderr,"Cannot open file \"%s\"\n",argv[1]);
    exit (2);
    }
  
  while(running)
    {
    token = yylex();
    if (! running) 
      break;
    switch (token)
      {
    case TK_IDENTIFIER: fprintf(stderr,"ident %s at line %d\n",yytext,LineNumber); break;
    case LIT_INTEGER: fprintf(stderr,"inteiro valor %d at line %d\n",atoi(yytext),LineNumber);  break;
    case TK_OPERATOR_STAR: fprintf(stderr,"asterisco at line %d\n",LineNumber);  break;
    case KW_INT : fprintf(stderr,"INT at line %d\n",LineNumber);  break;
    default: fprintf(stderr,"Nao sei... %d \n",token);
      } 
    }
  }

int yywrap ()
  {
  running = 0;
  return 1;
  }