Core Function BinaryReplace
BinaryReplace( <binary-array>, <needle>, <replacement>, <offset>, <maxReplacements> )
Contents |
Description
Search for a byte or string of bytes in a binary variable and replace it.
Parameters
binary-array
The binary variable to do the replacement on.
needle
The needle to find.
(It will be cast as binary if it isn't already)
replacement
The replacement to use.
(It will be cast as binary if it isn't already)
offset
Optional; Position to begin the search
Default: 0 (beginning)
maxReplacements
Optional; The max allowed replacements to do
Default: -1 (replace all)
Return Value
Success: Returns true.
Failure: Returns false.
Remarks
If you want to replace single bytes you SHOULD cast the find and replace as byte (see example) this is because if you don't do that then it will use a normal search and replace which involves splitting and remaking the binary.
Doing that on a single byte? Could potentially take a long time and would be rather silly when you can just simply cast to byte and replace on the spot with no need to break up and remake the binary.
Example
How to do a single byte replace for another byte
// To replace single bytes you must cast // your find AND replace as a byte // Assign a value to do the replace on $subject = Pack("A*", "Hello world!!!"); // Print unchanged say $subject; // "Hello world!!!" // Do the replacement BinaryReplace($subject, (byte)108, (byte)74); // Print changed say $subject; // HeJJo worJd!!!
Single byte replace using chars
// To replace single bytes you must cast // your find AND replace as a byte // to do this with chars is easy example // Assign a value to do the replace on $subject = Pack("A*", "Hello world!!!"); // Print unchanged say $subject; // "Hello world!!!" // Do the replacement BinaryReplace($subject, (byte)@'!', (byte)@'?'); // Print changed say $subject; // Hello world???
Simple replacement
// Assign a value to do the replace on $subject = Pack("A*", "Hello world!!!"); // Assign a value to find $find = Pack("A*", "world"); // Assign a value to replace the found with $replace = Pack("A*", "cat"); // Print unchanged say $subject; // Hello world!!! // Do the replacement BinaryReplace($subject, $find, $replace); // Print changed say $subject; // Hello cat!!!
This time the replacement is bigger than what is being replaced
// Assign a value to do the replace on $subject = Pack("A*", "Hello world!!!"); // Assign a value to find $find = Pack("A*", "world"); // Assign a value to replace the found with $replace = Pack("A*", "Spuntik"); // Print unchanged say $subject; // Hello world!!! // Do the replacement BinaryReplace($subject, $find, $replace); // Print changed say $subject; // Hello Spuntik!!!
Of course it will replace all it finds
// Assign a value to do the replace on $subject = Pack("A*", "Hello world ok world hehe world!!!"); // Assign a value to find $find = Pack("A*", "world"); // Assign a value to replace the found with $replace = Pack("A*", "Spuntik"); // Print unchanged say $subject; // Hello world ok world hehe world!!! // Do the replacement BinaryReplace($subject, $find, $replace); // Print changed say $subject; // Hello Spuntik ok Spuntik hehe Spuntik!!!
Only allow one replacement
// Assign a value to do the replace on $subject = Pack("A*", "Hello world ok world hehe world!!!"); // Assign a value to find $find = Pack("A*", "world"); // Assign a value to replace the found with $replace = Pack("A*", "Spuntik"); // Print unchanged say $subject; // Hello world ok world hehe world!!! // Do the replacement BinaryReplace($subject, $find, $replace, 0, 1); // Print changed say $subject; // Hello Spuntik ok world hehe world!!!
Only allow two replacements
// Assign a value to do the replace on $subject = Pack("A*", "Hello world ok world hehe world!!!"); // Assign a value to find $find = Pack("A*", "world"); // Assign a value to replace the found with $replace = Pack("A*", "Spuntik"); // Print unchanged say $subject; // Hello world ok world hehe world!!! // Do the replacement BinaryReplace($subject, $find, $replace, 0, 1); // Print changed say $subject; // Hello Spuntik ok Spuntik hehe world!!!
Using the offset to not replace the first match
// Assign a value to do the replace on $subject = Pack("A*", "Hello world ok world hehe world!!!"); // Assign a value to find $find = Pack("A*", "world"); // Assign a value to replace the found with $replace = Pack("A*", "Spuntik"); // Print unchanged say $subject; // Hello world ok world hehe world!!! // Do the replacement BinaryReplace($subject, $find, $replace, 10, 1); // Print changed say $subject; // Hello world ok Spuntik hehe world!!!
