Is it possible to view a binary in ones and zeros?

Question

By that I mean is it possible to write a program in C, compile it and then see what it looks like in ones and zeros? It would be cool to act like a 1337 hacker and pretend to actually program in ones and zeros :p .

Answer 1

Use hexdump or a hex editor to view a binary in hexadecimal bytes.

Hexadecimal is simply a more compact way to view binary. Every hexadecimal digit (0-F) represents four bits. For example, 0xF in decimal is 15 and in binary is 1111.

Answer 2

You can use xxd:

xxd -b filename

C:\opt\bin> xxd -b ctags.exe | head
0000000: 01001101 01011010 10010000 00000000 00000011 00000000  MZ....
0000006: 00000000 00000000 00000100 00000000 00000000 00000000  ......
000000c: 11111111 11111111 00000000 00000000 10111000 00000000  ......
0000012: 00000000 00000000 00000000 00000000 00000000 00000000  ......
0000018: 01000000 00000000 00000000 00000000 00000000 00000000  @.....
000001e: 00000000 00000000 00000000 00000000 00000000 00000000  ......
0000024: 00000000 00000000 00000000 00000000 00000000 00000000  ......
000002a: 00000000 00000000 00000000 00000000 00000000 00000000  ......
0000030: 00000000 00000000 00000000 00000000 00000000 00000000  ......
0000036: 00000000 00000000 00000000 00000000 00000000 00000000  ......

Just to make this a little more programming related:

#include <stdio.h>
#include <stdlib.h>

const char *lookup[] = {
   /*  0       1       2       3       4       5       6       7 */
    "0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111",
   /*  8       9       A       B       C       D       E       F */
    "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111",
};

int main(int argc, char *argv[]) {
    FILE *fin;
    int c;
    size_t bytes_read = 0;

    if ( argc != 2 ) {
        fputs("No filename provided", stderr);
        exit(EXIT_FAILURE);
    }

    fin = fopen(argv[1], "rb");
    if ( !fin ) {
        fprintf(stderr, "Cannot open %s\n", argv[1]);
        exit(EXIT_FAILURE);
    }

    while ( EOF != (c = fgetc(fin)) ) {
        printf("%s", lookup[ (c & 0xf0) >> 4 ]);
        printf("%s", lookup[ (c & 0x0f) ]);

        bytes_read += 1;
        if ( bytes_read % 9 == 0 ) {
            puts("");
        }
    }

    fclose(fin);

    return EXIT_SUCCESS;
}

Output:

C:\Temp> binary.exe c:\opt\bin\ctags.exe | head
010011010101101010010000000000000000001100000000000000000000000000000100
000000000000000000000000111111111111111100000000000000001011100000000000
000000000000000000000000000000000000000000000000010000000000000000000000
000000000000000000000000000000000000000000000000000000000000000000000000
000000000000000000000000000000000000000000000000000000000000000000000000
000000000000000000000000000000000000000000000000000000000000000000000000
000000000000000000000000000000000000000000000000111000000000000000000000
000000000000111000011111101110100000111000000000101101000000100111001101
001000011011100000000001010011001100110100100001010101000110100001101001
011100110010000001110000011100100110111101100111011100100110000101101101

Answer 3

Sure it's possible. You could write your own viewer using the information in this post.

Answer 4

You mean that you can't do compilation and translate the opcodes to binary in your head?

Actually, one of the computers I learned to program on had to have the bootstrap code toggled in via front panel switches. You needed to enter enough code to get it to boot the loader off the 8" floppy drive and load up the OS. You can see a picture of one here. I really did need to know the binary for the boot loader opcodes.