Configuration Variables
Below is a list of the most frequently used configuration variables. You can get a complete list by issuing e command without arguments. For example, to see all variables defined in the "cfg" namespace, issue e cfg. (mind the ending dot). You can get help on any eval configuration variable by using e? cfg.
The e?? command to get help on all the evaluable configuration variables of radare2. As long as the output of this command is pretty large you can combine it with the internal grep ~ to filter for what you are looking for:
The Visual mode has an eval browser that is accessible through the Vbe command.
asm.arch
Defines the target CPU architecture used for disassembling (pd, pD commands) and code analysis (a command). You can find the list of possible values by looking at the result of e asm.arch=? or rasm2 -L.
It is quite simple to add new architectures for disassembling and analyzing code. There is an interface for that. For x86, it is used to attach a number of third-party disassembler engines, including GNU binutils, Udis86 and a few handmade ones.
asm.bits
Determines width in bits of registers for the current architecture. Supported values: 8, 16, 32, 64. Note that not all target architectures support all combinations for asm.bits.
asm.syntax
Changes syntax flavor for disassembler between Intel and AT&T. At the moment, this setting affects Udis86 disassembler for Intel 32/Intel 64 targets only. Supported values are intel and att.
asm.pseudo
A boolean value to set the pseudo syntax in the disassembly. "False" indicates a native one, defined by the current architecture, "true" activates a pseudocode strings format. For example, it'll transform :
| 0x080483ff e832000000 call 0x8048436
| 0x08048404 31c0 xor eax, eax
| 0x08048406 0205849a0408 add al, byte [0x8049a84]
| 0x0804840c 83f800 cmp eax, 0
| 0x0804840f 7405 je 0x8048416
to
| 0x080483ff e832000000 0x8048436 ()
| 0x08048404 31c0 eax = 0
| 0x08048406 0205849a0408 al += byte [0x8049a84]
| 0x0804840c 83f800 var = eax - 0
| 0x0804840f 7405 if (!var) goto 0x8048416
It can be useful while disassembling obscure architectures.
asm.os
Selects a target operating system of currently loaded binary. Usually, OS is automatically detected by rabin -rI. Yet, asm.os can be used to switch to a different syscall table employed by another OS.
asm.flags
If defined to "true", disassembler view will have flags column.
asm.lines.call
If set to "true", draw lines at the left of the disassemble output (pd, pD commands) to graphically represent control flow changes (jumps and calls) that are targeted inside current block. Also, see asm.lines.out.
asm.lines.out
When defined as "true", the disassembly view will also draw control flow lines that go outside of the block.
asm.linestyle
A boolean value which changes the direction of control flow analysis. If set to "false", it is done from top to bottom of a block; otherwise, it goes from bottom to top. The "false" setting seems to be a better choice for improved readability and is the default one.
asm.offset
Boolean value which controls the visibility of offsets for individual disassembled instructions.
asm.trace
A boolean value that controls displaying of tracing information (sequence number and counter) at the left of each opcode. It is used to assist with programs trace analysis.
asm.bytes
A boolean value used to show or hide displaying of raw bytes of instructions.
asm.sub.reg
A boolean value used to replace register names with arguments or their associated role alias.
For example, if you have something like this:
| 0x080483ea 83c404 add esp, 4
| 0x080483ed 68989a0408 push 0x8049a98
| 0x080483f7 e870060000 call sym.imp.scanf
| 0x080483fc 83c408 add esp, 8
| 0x08048404 31c0 xor eax, eax
This variable changes it to:
| 0x080483ea 83c404 add SP, 4
| 0x080483ed 68989a0408 push 0x8049a98
| 0x080483f7 e870060000 call sym.imp.scanf
| 0x080483fc 83c408 add SP, 8
| 0x08048404 31c0 xor A0, A0
asm.sub.jmp
A boolean value used to substitute jump, call and branch targets in disassembly.
For example, when turned on, it'd display jal 0x80001a40 as jal fcn.80001a40 in the disassembly.
asm.sub.rel
A boolean value which substitutes pc relative expressions in disassembly. When turned on, it shows the references as string references.
For example:
0x5563844a0181 488d3d7c0e00. lea rdi, [rip + 0xe7c] ; str.argv__2d_:__s
When turned on, this variable lets you display the above instruction as:
0x5563844a0181 488d3d7c0e00. lea rdi, str.argv__2d_:__s ; 0x5563844a1004 ; "argv[%2d]: %s\n"
asm.sub.section
Boolean which shows offsets in disassembly prefixed with the name of the section or map.
That means, from something like:
0x000067ea 488d0def0c01. lea rcx, [0x000174e0]
to the one below, when toggled on.
0x000067ea 488d0def0c01. lea rcx, [fmap.LOAD1.0x000174e0]
asm.sub.varonly
Boolean which substitutes the variable expression with the local variable name.
For example: var_14h as rbp - var_14h, in the disassembly.
cfg.bigendian
Change endianness. "true" means big-endian, "false" is for little-endian. "file.id" and "file.flag" both to be true.
cfg.newtab
If this variable is enabled, help messages will be displayed along with command names in tab completion for commands.
scr.color
This variable specifies the mode for colorized screen output: "false" (or 0) means no colors, "true" (or 1) means 16-colors mode, 2 means 256-colors mode, 3 means 16 million-colors mode. If your favorite theme looks weird, try to bump this up.
scr.seek
This variable accepts a full-featured expression or a pointer/flag (eg. eip). If set, radare will set seek position to its value on startup.
scr.scrollbar
If you have set up any flagzones (fz?), this variable will let you display the scrollbar with the flagzones, in Visual mode. Set it to 1 to display the scrollbar at the right end, 2 for the top and 3 to display it at the bottom.
scr.utf8
A boolen variable to show UTF-8 characters instead of ANSI.
cfg.fortunes
Enables or disables "fortune" messages displayed at each radare start.
cfg.fortunes.type
Fortunes are classified by type. This variable determines which types are allowed for displaying when cfg.fortunes is true, so they can be fine-tuned on what's appropriate for the intended audience. Current types are tips, fun, nsfw, creepy.
stack.size
This variable lets you set the size of stack in bytes.