Having trouble reading strings from a file in C and manipluating them as an lc3 disassmbler

问题

I want to make a program that scans a file with contents of:

1283

5105

The hexcodes for two instructions in lc3:

add r1,r2,r3

and r0,r4,r5

I want my program to read this file and print the two corresponding instructions on the screen can someone please tell me what's wrong with it

 #include <stdio.h>
 #include <stdbool.h>
 #include <string.h>
     int main(int argc, char *argv[]) {


FILE *file;
char hexString[5];
int dr, sr1, sr2, instruction;
file = fopen(argv[1], "r");

while (fscanf(file, "%d", hexString) != EOF){

    unsigned short int instruction = (unsigned short)strtol(hexString, NULL, 16);

        if (instruction >> 12 == 0b0001){ //op code is ADD

            dr = (instruction >> 9) & 0b111; // turns other bits to zero
            sr1 = (instruction >> 6) & 0b111;
            sr2 = (instruction) & 0b111;

            printf("add r%d r%d r%d", dr, sr1, sr2);

        } else if (instruction >> 12 == 0b0101){//op code is AND

            dr = (instruction >> 9) & 0b111;
            sr1 = (instruction >> 6) & 0b111;
            sr2 = (instruction) & 0b111;

            printf("and r%d r%d r%d", dr, sr1, sr2);
        }
}
fclose(file);
}

No complie errors come up when I compile it using gcc.

Here is a copy of lc3 instruction set for reference http://ece224web.groups.et.byu.net/reference/LC3_Instructions.gif

来源：https://stackoverflow.com/questions/26456057/having-trouble-reading-strings-from-a-file-in-c-and-manipluating-them-as-an-lc3