구차니의 잡동사니 모음

#include "stdlib.h"
#include "limits.h"
#include "stdio.h"
#include "errno.h"


int
main(int argc, char *argv[])
{
   int base;
   char *endptr, *str;
   long val;


   if (argc < 2) {
	   fprintf(stderr, "Usage: %s str [base]\n", argv[0]);
	   exit(EXIT_FAILURE);
   }

   str = argv[1];
   base = (argc > 2) ? atoi(argv[2]) : 10;

   errno = 0;    /* To distinguish success/failure after call */
   val = strtol(str, &endptr, base);


   /* Check for various possible errors */

   if ((errno == ERANGE && (val == LONG_MAX || val == LONG_MIN))
		   || (errno != 0 && val == 0)) {
	   perror("strtol");
	   exit(EXIT_FAILURE);
   }


   if (endptr == str) {
	   fprintf(stderr, "No digits were found\n");
	   exit(EXIT_FAILURE);
   }


   /* If we got here, strtol() successfully parsed a number */

   printf("strtol() returned %ld\n", val);


   if (*endptr != ’\0’)        /* Not necessarily an error... */
	   printf("Further characters after number: %s\n", endptr);


   exit(EXIT_SUCCESS);
}