#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>

#define MAXTOKEN 256

#define P 0//stato pozza
#define q0 1
#define q1 2
#define q2 3
#define q3 4
#define q4 5

struct token
{
char name[MAXTOKEN+1];
int stato;
};

int gettoken (FILE *src,struct token *tkn,int max)
{
int car;
int i=0;
tkn->stato=q0;
if ((car=getc(src))!=EOF)
{
while (isspace(car))
car=getc(src);
while(car!=EOF && i<=max)
{
tkn->name[i]=car;
if ((isalpha(car))&&((car<97)||(car>122)))
tkn->stato=P;
else
{
switch (tkn->stato)
{
case q0:
if (car=='/')
tkn->stato=q1;
else
tkn->stato=P;
break;
case q1:
if (car=='*')
tkn->stato=q2;
else
tkn->stato=P;
break;
case q2:
if ((car=='*')||(car=='/'))
tkn->stato=q2;
else
if ((isalnum(car))||(car=='*')||(car=='_'))
tkn->stato=q3;
else
tkn->stato=P;
break;
case q3:
if (car=='*')
tkn->stato=q2;
else
if (car=='/')
tkn->stato=q4;
else
tkn->stato=P;
break;
case q4:
if (car!='\0')
tkn->stato=P;
break;
}
}
car=getc(src);
i++;
}
tkn->name[i]=0;
return 1;
}
else
return 0;
}

int main(int argc, char *argv[])
{
FILE *source;
source=fopen("prova.txt","r");
struct token next;
while (gettoken(source,&next,MAXTOKEN))
if ((next.stato==q1)||(next.stato==q4))
printf("Il token %s e' esatto.\n",next.name);
else
printf("Il token %s e' errato.\n",next.name);
fclose(source);  
printf("Premi un tasto per terminare l'esecuzione");	
getch();
  return 0;
}