Print Modes
One of the key features of radare2 is displaying information in many formats. The goal is to offer a selection of displaying choices to best interpret binary data.
Binary data can be represented as integers, shorts, longs, floats, timestamps, hexpair strings, or more complex formats like C structures, disassembly listings, decompilation listing, be a result of an external processing...
Below is a list of available print modes listed by p?:
[0x00005310]> p?
|Usage: p[=68abcdDfiImrstuxz] [arg|len] [@addr]
| p-[?][jh] [mode] bar|json|histogram blocks (mode: e?search.in)
| p=[?][bep] [N] [len] [b] show entropy/printable chars/chars bars
| p2 [len] 8x8 2bpp-tiles
| p3 [file] print stereogram (3D)
| p6[de] [len] base64 decode/encode
| p8[?][j] [len] 8bit hexpair list of bytes
| pa[edD] [arg] pa:assemble pa[dD]:disasm or pae: esil from hexpairs
| pA[n_ops] show n_ops address and type
| p[b|B|xb] [len] ([skip]) bindump N bits skipping M
| pb[?] [n] bitstream of N bits
| pB[?] [n] bitstream of N bytes
| pc[?][p] [len] output C (or python) format
| pC[d] [rows] print disassembly in columns (see hex.cols and pdi)
| pd[?] [sz] [a] [b] disassemble N opcodes (pd) or N bytes (pD)
| pf[?][.nam] [fmt] print formatted data (pf.name, pf.name $<expr>)
| ph[?][=|hash] ([len]) calculate hash for a block
| pj[?] [len] print as indented JSON
| p[iI][df] [len] print N ops/bytes (f=func) (see pi? and pdi)
| p[kK] [len] print key in randomart (K is for mosaic)
| pm[?] [magic] print libmagic data (see pm? and /m?)
| pq[?][iz] [len] print QR code with the first Nbytes of the current block
| pr[?][glx] [len] print N raw bytes (in lines or hexblocks, 'g'unzip)
| ps[?][pwz] [len] print pascal/wide/zero-terminated strings
| pt[?][dn] [len] print different timestamps
| pu[?][w] [len] print N url encoded bytes (w=wide)
| pv[?][jh] [mode] show variable/pointer/value in memory
| pwd display current working directory
| px[?][owq] [len] hexdump of N bytes (o=octal, w=32bit, q=64bit)
| pz[?] [len] print zoom view (see pz? for help)
[0x00005310]>
Tip: when using json output, you can append the ~{} to the command to get a pretty-printed version of the output:
[0x00000000]> oj
[{"raised":false,"fd":563280,"uri":"malloc://512","from":0,"writable":true,"size":512,"overlaps":false}]
[0x00000000]> oj~{}
[
{
"raised": false,
"fd": 563280,
"uri": "malloc://512",
"from": 0,
"writable": true,
"size": 512,
"overlaps": false
}
]
For more on the magical powers of ~ see the help in ?@?, and the "Command Format" chapter earlier in the book.
Hexadecimal View
px gives a user-friendly output showing 16 pairs of numbers per row with offsets and raw representations:
Show Hexadecimal Words Dump (32 bits)
8 bits Hexpair List of Bytes
[0x00404888]> p8 16
31ed4989d15e4889e24883e4f0505449
Show Hexadecimal Quad-words Dump (64 bits)
Date/Time Formats
Currently supported timestamp output modes are:
[0x00404888]> pt?
|Usage: pt[dn?]
| pt print unix time (32 bit cfg.big_endian)
| ptd print dos time (32 bit cfg.big_endian)
| ptn print ntfs time (64 bit !cfg.big_endian)
| pt? show help message
For example, you can 'view' the current buffer as timestamps in the ntfs time:
[0x08048000]> e cfg.bigendian = false
[0x08048000]> pt 4
29:04:32948 23:12:36 +0000
[0x08048000]> e cfg.bigendian = true
[0x08048000]> pt 4
20:05:13001 09:29:21 +0000
As you can see, the endianness affects the result. Once you have printed a timestamp, you can grep output, for example, by year value:
[0x08048000]> pt ~1974 | wc -l
15
[0x08048000]> pt ~2022
27:04:2022 16:15:43 +0000
The default date format can be configured using the cfg.datefmt variable. Formatting rules for it follow the well known strftime(3) format. Check the manpage for more details, but those are the more importants:
%a The abbreviated name of the day of the week according to the current locale.
%A The full name of the day of the week according to the current locale.
%d The day of the month as a decimal number (range 01 to 31).
%D Equivalent to %m/%d/%y. (Yecch—for Americans only).
%H The hour as a decimal number using a 24-hour clock (range 00 to 23).
%I The hour as a decimal number using a 12-hour clock (range 01 to 12).
%m The month as a decimal number (range 01 to 12).
%M The minute as a decimal number (range 00 to 59).
%p Either "AM" or "PM" according to the given time value.
%s The number of seconds since the Epoch, 1970-01-01 00:00:00 +0000 (UTC). (TZ)
%S The second as a decimal number (range 00 to 60). (The range is up to 60 to allow for occasional leap seconds.)
%T The time in 24-hour notation (%H:%M:%S). (SU)
%y The year as a decimal number without a century (range 00 to 99).
%Y The year as a decimal number including the century.
%z The +hhmm or -hhmm numeric timezone (that is, the hour and minute offset from UTC). (SU)
%Z The timezone name or abbreviation.
Basic Types
There are print modes available for all basic types. If you are interested in a more complex structure, type pf?? for format characters and pf??? for examples:
[0x00499999]> pf??
|pf: pf[.k[.f[=v]]|[v]]|[n]|[0|cnt][fmt] [a0 a1 ...]
| Format:
| b byte (unsigned)
| B resolve enum bitfield (see t?)
| c char (signed byte)
| d 0x%%08x hexadecimal value (4 bytes) (see %%i and %%x)
| D disassemble one opcode
| e temporally swap endian
| E resolve enum name (see t?)
| f float value (4 bytes)
| F double value (8 bytes)
| i %%i signed integer value (4 bytes) (see %%d and %%x)
| n next char specifies size of signed value (1, 2, 4 or 8 byte(s))
| N next char specifies size of unsigned value (1, 2, 4 or 8 byte(s))
| o 0x%%08o octal value (4 byte)
| p pointer reference (2, 4 or 8 bytes)
| q quadword (8 bytes)
| r CPU register `pf r (eax)plop`
| s 32bit pointer to string (4 bytes)
| S 64bit pointer to string (8 bytes)
| t UNIX timestamp (4 bytes)
| T show Ten first bytes of buffer
| u uleb128 (variable length)
| w word (2 bytes unsigned short in hex)
| x 0x%%08x hex value and flag (fd @ addr) (see %%d and %%i)
| X show formatted hexpairs
| z \0 terminated string
| Z \0 terminated wide string
| ? data structure `pf ? (struct_name)example_name`
| * next char is pointer (honors asm.bits)
| + toggle show flags for each offset
| : skip 4 bytes
| . skip 1 byte
Use triple-question to get some examples using print format strings.
[0x00499999]> pf???
|pf: pf[.k[.f[=v]]|[v]]|[n]|[0|cnt][fmt] [a0 a1 ...]
| Examples:
| pf 3xi foo bar 3-array of struct, each with named fields: 'foo' as hex, and 'bar' as int
| pf B (BitFldType)arg_name` bitfield type
| pf E (EnumType)arg_name` enum type
| pf.obj xxdz prev next size name Define the obj format as xxdz
| pf obj=xxdz prev next size name Same as above
| pf iwq foo bar troll Print the iwq format with foo, bar, troll as the respective names for the fields
| pf 0iwq foo bar troll Same as above, but considered as a union (all fields at offset 0)
| pf.plop ? (troll)mystruct Use structure troll previously defined
| pf 10xiz pointer length string Print a size 10 array of the xiz struct with its field names
| pf {integer}? (bifc) Print integer times the following format (bifc)
| pf [4]w[7]i Print an array of 4 words and then an array of 7 integers
| pf ic...?i foo bar "(pf xw yo foo)troll" yo Print nested anonymous structres
| pfn2 print signed short (2 bytes) value. Use N insted of n for printing unsigned values
Some examples are below:
[0x4A13B8C0]> pf i
0x00404888 = 837634441
[0x4A13B8C0]> pf
0x00404888 = 837634432.000000
High-level Languages Views
Valid print code formats for human-readable languages are:
pcCpc*print 'wx' r2 commandspchC half-words (2 byte)pcwC words (4 byte)pcdC dwords (8 byte)pcaGAS .byte blobpcA.bytes with instructions in commentspcsstringpcSshellscript that reconstructs the binpcjjsonpcJjavascriptpcppython
If we need to create a .c file containing a binary blob, use the pc command, that creates this output. The default size, is like in many other commands: the block size. Which can be changed with the b command.
But we can just temporarily override this block size by expressing it as argument.
[0xB7F8E810]> pc 32
#define _BUFFER_SIZE 32
unsigned char buffer[_BUFFER_SIZE] = {
0x89, 0xe0, 0xe8, 0x49, 0x02, 0x00, 0x00, 0x89, 0xc7, 0xe8, 0xe2, 0xff, 0xff, 0xff, 0x81, 0xc3, 0xd6, 0xa7, 0x01, 0x00, 0x8b, 0x83, 0x00, 0xff, 0xff, 0xff, 0x5a, 0x8d, 0x24, 0x84, 0x29, 0xc2 };
That cstring can used in many programming languages, not just C.
[0x7fcd6a891630]> pcs
"\x48\x89\xe7\xe8\x68\x39\x00\x00\x49\x89\xc4\x8b\x05\xef\x16\x22\x00\x5a\x48\x8d\x24\xc4\x29\xc2\x52\x48\x89\xd6\x49\x89\xe5\x48\x83\xe4\xf0\x48\x8b\x3d\x06\x1a
Strings
Strings are probably one of the most important entry points when starting to reverse engineer a program because they usually reference information about functions' actions (asserts, debug or info messages...) Therefore radare supports various string formats:
[0x00000000]> ps?
|Usage: ps[zpw] [N]Print String
| ps print string
| pss print string in screen (wrap width)
| psi print string inside curseek
| psb print strings in current block
| psx show string with escaped chars
| psz print zero terminated string
| psp print pascal string
| psu print utf16 unicode (json)
| psw print 16bit wide string
| psW print 32bit wide string
| psj print string in JSON format
Most strings are zero-terminated. Here is an example by using the debugger to continue the execution of a program until it executes the 'open' syscall. When we recover the control over the process, we get the arguments passed to the syscall, pointed by %ebx. In the case of the 'open' call, it is a zero terminated string which we can inspect using psz.
[0x4A13B8C0]> dcs open
0x4a14fc24 syscall(5) open ( 0x4a151c91 0x00000000 0x00000000 ) = 0xffffffda
[0x4A13B8C0]> dr
eax 0xffffffda esi 0xffffffff eip 0x4a14fc24
ebx 0x4a151c91 edi 0x4a151be1 oeax 0x00000005
ecx 0x00000000 esp 0xbfbedb1c eflags 0x200246
edx 0x00000000 ebp 0xbfbedbb0 cPaZstIdor0 (PZI)
[0x4A13B8C0]>
[0x4A13B8C0]> psz @ 0x4a151c91
/etc/ld.so.cache
Print Memory Contents
It is also possible to print various packed data types using the pf command:
[0xB7F08810]> pf xxS @ rsp
0x7fff0d29da30 = 0x00000001
0x7fff0d29da34 = 0x00000000
0x7fff0d29da38 = 0x7fff0d29da38 -> 0x0d29f7ee /bin/ls
This can be used to look at the arguments passed to a function. To achieve this, simply pass a 'format memory string' as an argument to pf, and temporally change the current seek position/offset using @. It is also possible to define arrays of structures with pf. To do this, prefix the format string with a numeric value. You can also define a name for each field of the structure by appending them as a space-separated arguments list.
[0x4A13B8C0]> pf 2*xw pointer type @ esp
0x00404888 [0] {
pointer :
(*0xffffffff8949ed31) type : 0x00404888 = 0x8949ed31
0x00404890 = 0x48e2
}
0x00404892 [1] {
(*0x50f0e483) pointer : 0x00404892 = 0x50f0e483
type : 0x0040489a = 0x2440
}
A practical example for using pf on a binary of a GStreamer plugin:
$ radare ~/.gstreamer-0.10/plugins/libgstflumms.so
[0x000028A0]> seek sym.gst_plugin_desc
[0x000185E0]> pf iissxsssss major minor name desc _init version \
license source package origin
major : 0x000185e0 = 0
minor : 0x000185e4 = 10
name : 0x000185e8 = 0x000185e8 flumms
desc : 0x000185ec = 0x000185ec Fluendo MMS source
_init : 0x000185f0 = 0x00002940
version : 0x000185f4 = 0x000185f4 0.10.15.1
license : 0x000185f8 = 0x000185f8 unknown
source : 0x000185fc = 0x000185fc gst-fluendo-mms
package : 0x00018600 = 0x00018600 Fluendo MMS source
origin : 0x00018604 = 0x00018604 http://www.fluendo.com
Disassembly
The pd command is used to disassemble code. It accepts a numeric value to specify how many instructions should be disassembled. The pD command is similar but instead of a number of instructions, it decompiles a given number of bytes.
d: disassembly N opcodes count of opcodesD: asm.arch disassembler bsize bytes
[0x00404888]> pd 1
;-- entry0:
0x00404888 31ed xor ebp, ebp
Selecting Target Architecture
The architecture flavor for disassembler is defined by the asm.arch eval variable. You can use e asm.arch=?? to list all available architectures.
[0x00005310]> e asm.arch=??
_dAe _8_16 6502 LGPL3 6502/NES/C64/Tamagotchi/T-1000 CPU
_dAe _8 8051 PD 8051 Intel CPU
_dA_ _16_32 arc GPL3 Argonaut RISC Core
a___ _16_32_64 arm.as LGPL3 as ARM Assembler (use ARM_AS environment)
adAe _16_32_64 arm BSD Capstone ARM disassembler
_dA_ _16_32_64 arm.gnu GPL3 Acorn RISC Machine CPU
_d__ _16_32 arm.winedbg LGPL2 WineDBG's ARM disassembler
adAe _8_16 avr GPL AVR Atmel
adAe _16_32_64 bf LGPL3 Brainfuck
_dA_ _32 chip8 LGPL3 Chip8 disassembler
_dA_ _16 cr16 LGPL3 cr16 disassembly plugin
_dA_ _32 cris GPL3 Axis Communications 32-bit embedded processor
adA_ _32_64 dalvik LGPL3 AndroidVM Dalvik
ad__ _16 dcpu16 PD Mojang's DCPU-16
_dA_ _32_64 ebc LGPL3 EFI Bytecode
adAe _16 gb LGPL3 GameBoy(TM) (z80-like)
_dAe _16 h8300 LGPL3 H8/300 disassembly plugin
_dAe _32 hexagon LGPL3 Qualcomm Hexagon (QDSP6) V6
_d__ _32 hppa GPL3 HP PA-RISC
_dAe _0 i4004 LGPL3 Intel 4004 microprocessor
_dA_ _8 i8080 BSD Intel 8080 CPU
adA_ _32 java Apache Java bytecode
_d__ _32 lanai GPL3 LANAI
...
Configuring the Disassembler
There are multiple options which can be used to configure the output of disassembler. All these options are described in e? asm.
[0x00005310]> e? asm.
asm.anal: Analyze code and refs while disassembling (see anal.strings)
asm.arch: Set the arch to be used by asm
asm.assembler: Set the plugin name to use when assembling
asm.bbline: Show empty line after every basic block
asm.bits: Word size in bits at assembler
asm.bytes: Display the bytes of each instruction
asm.bytespace: Separate hexadecimal bytes with a whitespace
asm.calls: Show callee function related info as comments in disasm
asm.capitalize: Use camelcase at disassembly
asm.cmt.col: Column to align comments
asm.cmt.flgrefs: Show comment flags associated to branch reference
asm.cmt.fold: Fold comments, toggle with Vz
...
Currently there are 136 asm. configuration variables so we do not list them all
Disassembly Syntax
The asm.syntax variable is used to change the flavor of the assembly syntax used by a disassembler engine. To switch between Intel and AT&T representations:
e asm.syntax = intel
e asm.syntax = att
You can also check asm.pseudo, which is an experimental pseudocode view,
and asm.esil which outputs ESIL ('Evaluable Strings Intermediate Language'). ESIL's goal is to have a human-readable representation of every opcode semantics. Such representations can be evaluated (interpreted) to emulate effects of individual instructions.