当 c 程序运行时，打印大量的垃圾

Question

I am trying to write a program that takes a file from the command line and then prints it out in a 2D array so that I can call specific elements. I had a previous error because I closed the pointer in the loop instead of the main body but now that I've fixed that something else comes up when I run the program. It prints out the contents like I want but then after it prints out &�be���~����0��~�����~���0��~�'~�~�� 0��@�����~�� � � � ����� � hr ��0��~�@������~�M��o"V0U�~���o"V��o"V what am I doing wrong here?

 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
 
 int main(int argc, char* argv[]){
      int i;
      int j;
      char tttInput[20][20];
      FILE *tttInputPtr = fopen(argv[1], "r");
    
      if (tttInputPtr == NULL) {
        printf("Unable to open file\n");
        return 1;
      }
      for(i=0; i<20; i++){
        for(j=0; j<20; j++){
          fscanf(tttInputPtr, "%c", &tttInput[i][j]);
        }
      }
      for(i=0; i<20; i++){
        for(j=0; j<20; j++){
          printf("%c", tttInput[i][j]);
        }
      }
      fclose(tttInputPtr);
      return 0;
    }

Answer 1

      for(i=0; i<20; i++){
        for(j=0; j<20; j++){
          fscanf(tttInputPtr, "%c", &tttInput[i][j]);
        }
      }
      for(i=0; i<20; i++){
        for(j=0; j<20; j++){
          printf("%c", tttInput[i][j]);
        }
      }

This loop will attempt to read 400 characters from the input and print them all. But you don't have 400 so it prints garbage.

Solution: stop iteration on second loop after read failure

      int ni, nj;
      for(ni=0; ni<20; ni++){
        for(nj=0; nj<20; nj++){
          if (1 > fscanf(tttInputPtr, "%c", &tttInput[ni][nj]))
              goto break2; /* there has got to be a nicer way to break 2 loops at once */
        }
      }
;break2:
      for(i=0; i<=ni; i++){
        for(j=0; j<=((i == ni) ? nj : 20); j++){
          printf("%c", tttInput[i][j]);
        }
      }

I really feel there's a nicer way to break out of the two loops, and again I really feel there's got to be a nicer loop condition for the loop control of the inner loop.

Maybe there is if you revealed why you used a two-dimensional array for the input. This particular code would be so much nicer without it, but it doesn't look like an accident.