The core reads ~/.config/radare2/radare2rc while starting. You can add e commands to this file to tune the radare2 configuration to your taste.

To prevent radare2 from parsing this file at startup, pass it the -N option.

All the configuration of radare2 is done with the eval commands. A typical startup configuration file looks like this:

$ cat ~/.radare2rc
e scr.color = 1
e dbg.bep   = loader

The configuration can also be changed with -e <config=value> command-line option. This way you can adjust configuration from the command line, keeping the .radare2rc file intact. For example, to start with empty configuration and then adjust scr.color and asm.syntax the following line may be used:

$ radare2 -N -e scr.color=1 -e asm.syntax=intel -d /bin/ls

Internally, the configuration is stored in a hash table. The variables are grouped in namespaces: cfg., file., dbg., scr. and so on.

To get a list of all configuration variables just type e in the command line prompt. To limit the output to a selected namespace, pass it with an ending dot to e. For example, e file. will display all variables defined inside the "file" namespace.

To get help about e command type e?:

Usage: e [var[=value]]  Evaluable vars
| e?asm.bytes     show description
| e??             list config vars with description
| e a             get value of var 'a'
| e a=b           set var 'a' the 'b' value
| e var=?         print all valid values of var
| e var=??        print all valid values of var with description
| e.a=b           same as 'e a=b' but without using a space
| e,k=v,k=v,k=v   comma separated k[=v]
| e-              reset config vars
| e*              dump config vars in r commands
| e!a             invert the boolean value of 'a' var
| ec [k] [color]  set color for given key (prompt, offset, ...)
| eevar           open editor to change the value of var
| ed              open editor to change the ~/.radare2rc
| ej              list config vars in JSON
| env [k[=v]]     get/set environment variable
| er [key]        set config key as readonly. no way back
| es [space]      list all eval spaces [or keys]
| et [key]        show type of given config variable
| ev [key]        list config vars in verbose format
| evj [key]       list config vars in verbose format in JSON

A simpler alternative to the e command is accessible from the visual mode. Type Ve to enter it, use arrows (up, down, left, right) to navigate the configuration, and q to exit it. The start screen for the visual configuration edit looks like this:


    >  anal

For configuration values that can take one of several values, you can use the =? operator to get a list of valid values:

[0x00000000]> e scr.nkey = ?
scr.nkey = fun, hit, flag