\x7fELF
echo $[$$%5]
Note that non-ascii characters in the above source code will be escaped (such as \x9f).
Disassemble:
00000000 <.data>: 0: 7f 45 jg 0x47 2: 4c dec %esp 3: 46 inc %esi 4: 0a 65 63 or 0x63(%ebp),%ah 7: 68 6f 20 24 5b push $0x5b24206f c: 24 24 and $0x24,%al e: 25 .byte 0x25 f: 35 .byte 0x35 10: 5d pop %ebp