I am confusing of my C program in the case of giving a txt file to my executable program

I wanna count numbers of every Ascii characters from text file. So I prgrammed my C file that can read text file. Here is my C source code.

#include <stdio.h>
int main()
{
       /*c언어 소스파일을 컴파일 한 뒤 ./{실행파일명}<{넣어줄 파일명}으로 터미널에 입력하면 파일의 내용이 input으로 들어간다.
    어떠한 자료구조에 넣어주는 것이 효율적일 것인가? ==> 그냥 무식하게 하나하나 다 세는 방법도 있긴 함. 

    */
   int myAsciiList[128]={0,};//나올 때마다 더해줄 아스키 코드임.
   char gettingChar;//매번 입력받을 것을 말한다.
   scanf("%c",&gettingChar);//먼저 파일로부터 문자를 하나 입력 받는다.
   int myIndex;
   myIndex=gettingChar;
   myAsciiList[myIndex]++;
   while(1)//계속해서 입력을 받아들인다.
   {
       scanf("%c",&gettingChar);
       if(gettingChar==EOF) break;
       else{
              myIndex=gettingChar;
              myAsciiList[myIndex]++;
       }
   }
   
   return 0;
}

I compiled my C source code by using Visual Studio Code and made executable file. And then I gave my text file in terminal with command "./count < input.txt".</br>

But my terminal does not show me anything. Like this,</br>
MacBookAir  ~/Desktop/2023_Algorithm/hw4   main ±  ./count < test.txt

</br>
Can you recommend me how to fix my code?😂

1. Use symbolic constants LEN instead hard-coding magic values. Especially when you need use the same variable in two places.

2. (Not fixed) Consider using a unsigned type (like unsigned or size_t) instead of (signed) int for myAsciiList. This better captures the intend of positive counts.

3. It's implementation defined if char is signed or unsigned. If it's signed, a negative value will cause a buffer underflow. You also assume that the less than 128 otherwise it would cause a buffer overflow.

4. You have the same code before the loop as in it. This is probably a mistake. Also, before the loop you don't implement error handling which is problematic (if it worked). It's a good idea to eliminate duplicate code. In this case I could just remove it, other times to move duplicate code into a function and call it the function as many times as needed instead.

5. scanf() returns EOF. It does not set the variable gettingChar to it.

6. You need to print something if you want output.

7. Minimize number and scope of variables whenever possible. char ch; is now declared just before it's use. myIndex was eliminated as it's was the same value as ch and below I cast it to an unsigned value when needed.

8. (Not fixed) Consider special handling of non-printable characters like space, newline or tab when you print out the result.

You probably want something along these lines:

#include <stdio.h>

#define LEN 128

int main() {
	int myAsciiList[LEN] = {0};
	for(;;) {
		char ch;
		int rv = scanf("%c", &ch);
		if(rv == EOF)
			break;
		if(!rv) {
			printf("scanf failed\n");
			break;
		}
		if((unsigned) ch >= LEN) {
			printf("ch is too large\n");
			break;
		}
		myAsciiList[(unsigned) ch]++;
	}
	for(size_t i = 0; i < LEN; i++) {
		if(myAsciiList[i])
			printf("%c: %d\n", (char) i, myAsciiList[i]);
	}
}

and here is an example run with the source file as input:

$ ./count < count.c
        : 41

: 26
 : 38
!: 1
": 8
#: 2
%: 3
&: 1
(: 14
): 14
+: 4
,: 3
.: 1
0: 2
1: 1
2: 1
8: 1
:: 1
;: 14
<: 2
=: 6
>: 2
A: 4
E: 5
F: 1
L: 8
N: 4
O: 1
[: 4
\: 3
]: 4
_: 1
a: 10
b: 3
c: 16
d: 7
e: 11
f: 13
g: 3
h: 8
i: 37
k: 3
l: 3
m: 5
n: 18
o: 5
p: 3
r: 14
s: 15
t: 13
u: 3
v: 3
y: 4
z: 1
{: 6
}: 6