Udis86 Disassembler Library for x86 / x86-64

libudis86

A disassembler library for the x86 architecture which allows you to decode a stream of bytes as x86 instructions, inspect various bits of information about them, and even translate to human readable assembly language form.

#include <stdio.h>
#include <udis86.h>

int main()
{
    ud_t ud_obj;

    ud_init(&ud_obj);
    ud_set_input_file(&ud_obj, stdin);
    ud_set_mode(&ud_obj, 64);
    ud_set_syntax(&ud_obj, UD_SYN_INTEL);

    while (ud_disassemble(&ud_obj)) {
        printf("\t%s\n", ud_insn_asm(&ud_obj));
    }

    return 0;
}

• Supports 16bit, 32bit and 64bit modes.
• General purpose and sytem instructions; media extensions such as MMX, 3DNow, SSE, SSE2, SSE3, SSSE3, SSE4.1, SSE4.2; FPU (x87); AMD-V and INTEL-VMX, etc.
• Generates output in INTEL style (NASM, YASM etc.) and AT&T-style (GNU assembler) output syntax.
• Flexible input interface: Memory buffers, standard library FILEs, and function callbacks.

udcli

udcli is a command-line tool for your quick disassembly needs.

$ echo "65 67 89 87 76 65 54 56 78 89 09 00 87" | udcli -32 -x
0000000000000000 656789877665    mov [gs:bx+0x6576], eax
0000000000000000 54              push esp
0000000000000000 56              push esi
0000000000000000 7889            js 0x93 
0000000000000000 0900            or [eax], eax

Project

Note Active development of the project has now moved to Github at https://github.com/vmt/udis86. Please use the issue tracker to report bugs.