Command Format

A general format for radare2 commands is as follows:

[.][times][cmd][~grep][@[@iter]addr!size][|>pipe] ;

People who use Vim daily and are familiar with its commands will find themselves at home. You will see this format used throughout the book. Commands are identified by a single case-sensitive character [a-zA-Z].

To repeatedly execute a command, prefix the command with a number:

px    # run px
3px   # run px 3 times

The ! prefix is used to execute a command in shell context. If you want to use the cmd callback from the I/O plugin you must prefix with =!.

Note that a single exclamation mark will run the command and print the output through the RCons API. This means that the execution will be blocking and not interactive. Use double exclamation marks -- !! -- to run a standard system call.

All the socket, filesystem and execution APIs can be restricted with the cfg.sandbox configuration variable.

A few examples:

ds                    ; call the debugger's 'step' command
px 200 @ esp          ; show 200 hex bytes at esp
pc > file.c           ; dump buffer as a C byte array to file.c
wx 90 @@ sym.*        ; write a nop on every symbol
pd 2000 | grep eax    ; grep opcodes that use the 'eax' register
px 20 ; pd 3 ; px 40  ; multiple commands in a single line

The standard UNIX pipe | is also available in the radare2 shell. You can use it to filter the output of an r2 command with any shell program that reads from stdin, such as grep, less, wc. If you do not want to spawn anything, or you can't, or the target system does not have the basic UNIX tools you need (Windows or embedded users), you can also use the built-in grep (~).

See ?~? for help.

The ~ character enables internal grep-like function used to filter output of any command:

pd 20~call            ; disassemble 20 instructions and grep output for 'call'

Additionally, you can grep either for columns or for rows:

pd 20~call:0          ; get first row
pd 20~call:1          ; get second row
pd 20~call[0]         ; get first column
pd 20~call[1]         ; get second column

Or even combine them:

pd 20~call:0[0]       ; grep the first column of the first row matching 'call'

This internal grep function is a key feature for scripting radare2, because it can be used to iterate over a list of offsets or data generated by disassembler, ranges, or any other command. Refer to the loops section (iterators) for more information.

The @ character is used to specify a temporary offset at which the command to its left will be executed. The original seek position in a file is then restored.

For example, pd 5 @ 0x100000fce to disassemble 5 instructions at address 0x100000fce.

Most of the commands offer autocompletion support using <TAB> key, for example seek or flags commands. It offers autocompletion using all possible values, taking flag names in this case. Note that it is possible to see the history of the commands using the !~... command - it offers a visual mode to scroll through the radare2 command history.

To extend the autocompletion support to handle more commands or enable autocompletion to your own commands defined in core, I/O plugins you must use the !!! command.

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