bytes

is vb capable of going to cetrain offsets in a file and editing single bytes?

if so wht do i need to know?

Not really. You can load an array of bytes and access them using the array index though. Does that help?

Sure it can. The following code opens a file, gets the byte at position 87, checks if it is the letter A and if it isn't sets it to the letter A. Check out these I/O functions in your help file - Open, Get, Put, Seek (statement), Seek (function), LOC, LOF, Close

VB Code:

Dim lngFileNo as Long 
Dim bytData as Byte 
 
lngFileNo = FreeFile
 
Open FileName For Binary As lngFileNo
 
Get lngFileNo, 87, bytData
 
If bytData <> Asc("A") then
   Put lngFileNo, 87, asc("A")
End If
 
Close lngFileNo

ok i need to get to offset 0x3A7E3

and chnage it from 0D to 00

how would i do this?

cuz that way didn't work

Did you try changing the hex value to its decimal equivalent of 239587 and using 13 as the replacement value?

no i did not...i guess i'll have to find my hex calc

I did the math for you.

thanks for that...it will help..not sure if this is resolved cuz i havn't tried it...still gotta another project to get done

btw is there an equation for this....or wht...hex calc?

Windows calculator can do that

plz expand on this

attached

There is no conversion necessary, VB will handle everything. In VB, you represent hexadecimal numbers directly by using the prefix &H instead of 0x.

VB Code:

Dim lngFileNo As Long
Dim bytData As Byte
 
lngFileNo = FreeFile
 
Open FileName For Binary As lngFileNo
 
Get lngFileNo, &H3A7E3, bytData
 
If bytData <> &HD Then
   Put lngFileNo, &H3A7E3, &H0
End If
 
Close lngFileNo

Opps - misread the original request. I thought hacker was refering to memory blocks (assembler background kicked in) not files. Apologies for the bum steer.

But actually, I am wrong again. This explains the first steps of even doing that (using StrPtr, VarPtr and ObjPtr). You live and learn. :thumb:

alright thats awesome thanks alot to all who helped

First off, I am terribly sorry for bringing up a topic thats been buried for 3 years. But I couldn't find any others on my question.
My question is that is there a way to select a region like &H420 to &H430 and check for the things in there and edit it at once? Along the lines of something like:

Code:

---

Dim lngFileNo As Long
      Dim bytData As Byte
      lngFileNo = FreeFile
      Open FileName For Binary As lngFileNo
      Get lngFileNo, &H3A7E3, bytData
      If bytData <> &HD Then
        Put lngFileNo, &H3A7E3, &H0
      End If
            Close lngFileNo

---

Get all the bytes in the range and put them into an array.

Code:

---

Dim bytData() as Byte
Redim bytData(&H430 - &H420)
Get lngFileNo, &H3A7E3, bytData
'code to check and change bytData array
'now overwrite the existing data in the file
Put lngFileNo, &H3A7E3, bytData

---

Just be careful when working with binary files at the byte level. If anything is incorrect the file could become "corrupt"...

ah thank you so much for the quick reply
but i have 1 more question, is there a way to put together &H and a variable i want to do &H & var & but it just wont work :S

Quote:

---

Originally Posted by majin

First off, I am terribly sorry for bringing up a topic thats been buried for 3 years. But I couldn't find any others on my question.
My question is that is there a way to select a region like &H420 to &H430 and check for the things in there and edit it at once? Along the lines of something like:

Code:

---

Dim lngFileNo As Long
      Dim bytData As Byte
      lngFileNo = FreeFile
      Open FileName For Binary As lngFileNo
      Get lngFileNo, &H3A7E3, bytData
      If bytData <> &HD Then
        Put lngFileNo, &H3A7E3, &H0
      End If
            Close lngFileNo

---

---

Next time we'd prefer if you started a new thread.