Patch API

Purpose

Patch API reads, writes, and reverts process memory.

Header

C:

#include <pl/c/Patch.h>

C++:

#include <pl/cpp/Patch.hpp>

Signatures

C:

bool pl_patch_write_bytes(uintptr_t addr, const uint8_t *bytes,
                          size_t len, const char *name);
bool pl_patch_write_hex(uintptr_t addr, const char *bytes,
                        const char *name);
size_t pl_patch_read_bytes(uintptr_t addr, uint8_t *out, size_t len);
bool pl_patch_revert(const char *name);
void pl_patch_revert_all(void);

C++:

namespace pl::patch {
bool writeBytes(uintptr_t addr, const std::string &bytes,
                const std::string &name);
bool writeBytes(uintptr_t addr, const std::vector<uint8_t> &bytes,
                const std::string &name);
std::vector<uint8_t> readBytes(uintptr_t addr, size_t len);
bool revert(const std::string &name);
void revertAll();
}

pl_patch_write_bytes / writeBytes

Purpose

Writes bytes to an address and stores original bytes under name.

Parameters

Parameter	Description
addr	Target address
bytes	Byte buffer or hex byte string, such as "00 00 80 D2"
len	Number of bytes in the buffer
name	Patch name for later revert

Return Value

Returns true on success. Returns false when bytes are empty, a hex string is invalid, addr is 0, the target range is not readable, the address range overflows, or memory permission changes fail.

C Example

#include <pl/c/Patch.h>

const uint8_t bytes[] = {0x00, 0x00, 0x80, 0xD2, 0xC0, 0x03, 0x5F, 0xD6};
bool ok = pl_patch_write_bytes(address, bytes, sizeof(bytes), "return_zero");

C++ Example

#include <pl/cpp/Patch.hpp>

bool ok = pl::patch::writeBytes(address, "00 00 80 D2 C0 03 5F D6",
                                "return_zero");

pl_patch_read_bytes / readBytes

Purpose

Reads bytes from an address.

Parameters

Parameter	Description
addr	Start address
out	Caller-owned output buffer
len	Number of bytes to read

Return Value

The C API returns the number of bytes read. It returns 0 when out is NULL, addr is 0, len is 0, the address range overflows, or the target range is not readable.

The C++ wrapper returns the read bytes, or an empty vector on failure.

pl_patch_revert / revert

Purpose

Reverts one named patch.

Parameters

Parameter	Description
name	Patch name passed to write

Return Value

Returns true on success, otherwise false.

pl_patch_revert_all / revertAll

Purpose

Reverts all recorded patches.

Notes

• Reusing a patch name overwrites the previous record.
• Saved original byte length equals the write length.
• Hex strings are whitespace-separated bytes. Each byte token must contain one or two hex digits.
• writeBytes and readBytes reject invalid addresses where possible, but wrong instruction bytes or patching the wrong function can still crash the process.
• Prefer the C++ helpers in new C++ mods.