NAME
Devel::PeekPoke - All your bytes are belong to us
DESCRIPTION
This module provides a toolset for raw memory manipulation (both reading and writing), together with some tools making it easier to examine memory chunks.
All provided routines expect memory addresses as regular integers (not as their packed representations). Note that you can only manipulate memory of your current perl process, this is not a general memory access tool.
PORTABILITY
The implementation is very portable, and is expected to work on all architectures and operating systems supported by perl itself. Moreover no compiler toolchain is required to install this module (in fact currently no XS version is available).
In order to interpret the results, you may need to know the details of the underlying system architecture. See Devel::PeekPoke::Constants for some useful constants related to the current system.
USE RESPONSIBLY
It is apparent with the least amount of imagination that this module can be used for great evil and general mischief. On the other hand there are some legitimate uses, if nothing else as a learning/debugging tool. Hence this tool is provided ( with Larry Wall's blessing! ) in the interest of free speech and all. The authors expect a user of this module to exercise maximum common sense.
EXPORTABLE FUNCTIONS
The following functions are provided, with "peek" and "poke" being exported by default.
peek
my $byte_string = peek( $address, $size );Reads and returns $size bytes from the supplied address. Expects $address to be specified as an integer.
poke
my $bytes_written = poke( $address, $bytes );Writes the contents of $bytes to the memory location $address. Returns the amount of bytes written. Expects $bytes to be a raw byte string, throws an exception when (possible) characters are detected.
peek_address
my $address = peek_address( $pointer_address );A convenience function to retrieve an address from a known location of a pointer. The address is returned as an integer. Equivalent to:
unpack (
Devel::PeekPoke::Constants::PTR_PACK_TYPE,
peek( $pointer_address, Devel::PeekPoke::Constants::PTR_SIZE ),
)poke_address
my $addr_size = poke_address( $pointer_address, $address_value );A convenience function to set a pointer to an arbitrary address an address (you need to ensure that $pointer_address is in fact a pointer). Equivalent to:
poke( $pointer_address, pack (
Devel::PeekPoke::Constants::PTR_PACK_TYPE,
$address_value,
));peek_verbose
peek_verbose( $address, $size )A convenience wrapper around "describe_bytestring". Equivalent to:
print STDERR describe_bytestring( peek($address, $size), $address);describe_bytestring
my $desc = describe_bytestring( $bytes, $start_address )A convenience aid for examination of random bytestrings. Useful for those of us who are not skilled enough to read hex dumps directly. For example:
describe_bytestring( "Har har\t\x13\x37\xb0\x0b\x1e\x55 !!!", 46685601519 )
returns the following on a little-endian system (regardless of pointer size):
Hex Dec Oct Bin ASCII 32 32+2 64
-------------------------------- -------- -------- ----------------
0xadeadbeef 48 72 110 01001000 H 20726148 0972616820726148
0xadeadbef0 61 97 141 01100001 a ___/ _______/
0xadeadbef1 72 114 162 01110010 r __/ 61682072 ______/
0xadeadbef2 20 32 40 00100000 (SP) _/ ___/ _____/
0xadeadbef3 68 104 150 01101000 h 09726168 __/ ____/
0xadeadbef4 61 97 141 01100001 a ___/ _/ ___/
0xadeadbef5 72 114 162 01110010 r __/ 37130972 __/
0xadeadbef6 09 9 11 00001001 (HT) _/ ___/ _/
0xadeadbef7 13 19 23 00010011 (DC3) 0BB03713 __/ 2120551E0BB03713
0xadeadbef8 37 55 67 00110111 7 ___/ _/ _______/
0xadeadbef9 B0 176 260 10110000 "\260" __/ 551E0BB0 ______/
0xadeadbefa 0B 11 13 00001011 (VT) _/ ___/ _____/
0xadeadbefb 1E 30 36 00011110 (RS) 2120551E __/ ____/
0xadeadbefc 55 85 125 01010101 U ___/ _/ ___/
0xadeadbefd 20 32 40 00100000 (SP) __/ 21212120 __/
0xadeadbefe 21 33 41 00100001 ! _/ ___/ _/
0xadeadbeff 21 33 41 00100001 ! __/
0xadeadbf00 21 33 41 00100001 ! _/AUTHOR
ribasushi: Peter Rabbitson <ribasushi@cpan.org>
CONTRIBUTORS
None as of yet
COPYRIGHT
Copyright (c) 2011 the Devel::PeekPoke "AUTHOR" and "CONTRIBUTORS" as listed above.
LICENSE
This library is free software and may be distributed under the same terms as perl itself.