Question

I have got this code that reads an integer using scanf and checks if it is actually an integer by looking at the buffer.

int e_1; 
char c[1];
// noNeedToCleanBuffer is used to avoid buffer cleaning the first time.
int noNeedToCleanBuffer = 1;
do {
    // Clears the buffer.
    if (!noNeedToCleanBuffer)
        while ((c[0] = getchar()) != '\n') ;

    noNeedToCleanBuffer = 0;
    printf("Input an integer value: \n");
    e_1 = scanf("%d", &n);  

    c[0] = getchar();
} while ((e_1 != 1 && c[0] != 10) || (e_1 == 1 && c[0] != 10));

However I cannot figure out how to check if the input is between INT_MIN and INT_MAX (I get these from limits.h).

I was thinking of getting the number as a string and compare it with two strings that would represent INT_MIN and INT_MAX, but since I am using the standard c99 I am not allowed to use atoi() or itoa().

Answer 1

If you really just want to check store it-

1.)Store in long and then check

2.)Store the number in string then convert the INT_MAX into a string by getting each digit and storing in string and then using strcmp()

num = INT_MAX;
i = 0;

while(num != 0){
    str[i] = num % 10;
    num = num / 10;
    i++;
}

The number would be opposite in this string you can get it reversed quite easily by a simple loop

Then use strcmp();