const char *number = "10";
char *end;
long int value = strtol(number, &end, 10);
if (end == number || *end != ' ' || errno == ERANGE)
printf("Not a number");
else
printf("Value: %ld", value);
const char *number = "10";
char *end;
long int value = strtol(number, &end, 10);
if (end == number || *end != ' ' || errno == ERANGE)
printf("Not a number");
else
printf("Value: %ld", value);