Editing EXE file to swap values

[NOVARSEG]

So using a hex editor :)  it is possible to find the address bytes in a QB64 EXE and swap the address of one variable with another.

This is the BAS file (complied and then edited the EXE)

It swaps A with B.  Only had to change two bytes with the editor.


DIM A AS _UNSIGNED LONG
DIM B AS _UNSIGNED LONG


GOSUB LL1
PRINT A
PRINT B


END

LL1:

A = 808530224 ' look for "0110"
B = 825373233  ' look for "1221"


RETURN

**** This is for experiment only, do not adjust your set

If anyone wants the EXE then say so

[SpriggsySpriggs]

Look at OpenProcess on the MSDN

[SMcNeill]

Easy way is to just open your source and then: SWAP A, B

[NOVARSEG]

Yep that works too.


 what the unedited bytes look like in the EXE

A1 4C 2B 6B 00        'address = 6B2B4C
C7 00 30 31 31 30    '30 31 31 30 = 808530224 dec

A1 50 2B 6B 00         'address = 6B2B50
C7 00 31 32 32 31     '31 32 32 31 = 825373233 dec

****

the edited bytes

A1 50 2B 6B 00        'address = 6B2B50
C7 00 30 31 31 30    '30 31 31 30 = 808530224 dec

A1 4C 2B 6B 00         'address = 6B2B4C
C7 00 31 32 32 31     '31 32 32 31 = 825373233 dec

notice the LONGs are 4 bytes apart so there are no spaces between.