如何复制文件的二进制数据

Question

Basically, I am trying to read binary data of a file by using fread() and print it on screen using printf(), now, the problem is that when it prints it out, it actually don't show it as binary 1 and 0 but printing symbols and stuff which I don't know what they are.

This is how I am doing it:

#include <stdio.h>
#include <windows.h>


int main(){
    size_t  sizeForB, sizeForT;
    char    ForBinary[BUFSIZ], ForText[BUFSIZ];

    char    RFB []      = "C:\\users\\(Unknown)\\Desktop\\hi.mp4"   ;       // Step 1

    FILE    *ReadBFrom  = fopen(RFB , "rb" );

    if(ReadBFrom == NULL){
        printf("Following File were Not found: %s", RFB);
        return -1;
    } else {
        printf("Following File were found: %s\n", RFB);                              // Step 2
        while(sizeForB = fread(ForBinary, 1, BUFSIZ, ReadBFrom)){                      // Step 1
           printf("%s", ForBinary);
        }
        fclose(ReadBFrom);

    }

    return 0;
}

I would really appreciate if someone could help me out to read the actual binary data of a file as binary (0,1).

Answer 1

 while(sizeForB = fread(ForBinary, 1, BUFSIZ, ReadBFrom)){             
           printf("%s", ForBinary);  }

This is wrong on many levels. First of all you said it is binary file - which means there might not be text in it in the first place, and you are using %s format specifier which is used to print null terminated strings. Again since this is binary file, and there might not be text in it in the first place, %s is the wrong format specifier to use. And even if there was text inside this file, you are not sure that fread would read a "complete" null terminated string that you could pass to printf with format specifier %s .

What you may want to do is, read each byte form a file, convert it to a binary representation (google how to convert integer to binary string say, eg, here ), and print binary representation for each that byte.

Basically pseudocode:

foreach (byte b in FileContents)
{
  string s = convertToBinary(b);
  println(s);
}

Answer 2

How to view files in binary in the terminal?

Either

"hexdump -C yourfile.bin" perhaps, unless you want to edit it of course. Most linux distros have hexdump by default (but obviously not all).

or

xxd -b file

Answer 3

To simply read a file and print it in binary (ones and zeros), read it one char at a time. Then for each bit, print a '0' or '1' . Can print Most or Least significant bit first. Suggest MSb.

if (ReadBFrom) {
  int ch;
  while ((ch = fgetc(ReadBFrom)) != EOF) {
    unsigned mask = 1u << (CHAR_BIT - 1);  // CHAR_BIT is typically 8
    while (mask) {
       putchar(mask & ch ? '1' : '0');
       mask >>= 1;
    }
  }
  fclose(ReadBFrom);
}