The radare core accepts many flags from the command line.
This is an excerpt from the usage help message:
$ radare2 -h
Usage: r2 [-ACdfLMnNqStuvwzX] [-P patch] [-p prj] [-a arch] [-b bits] [-i file]
[-s addr] [-B baddr] [-m maddr] [-c cmd] [-e k=v] file|pid|-|--|=
-- run radare2 without opening any file
- same as 'r2 malloc://512'
= read file from stdin (use -i and -c to run cmds)
-= perform !=! command to run all commands remotely
-0 print \x00 after init and every command
-2 close stderr file descriptor (silent warning messages)
-a [arch] set asm.arch
-A run 'aaa' command to analyze all referenced code
-b [bits] set asm.bits
-B [baddr] set base address for PIE binaries
-c 'cmd..' execute radare command
-C file is host:port (alias for -c+=http://%s/cmd/)
-d debug the executable 'file' or running process 'pid'
-D [backend] enable debug mode (e cfg.debug=true)
-e k=v evaluate config var
-f block size = file size
-F [binplug] force to use that rbin plugin
-h, -hh show help message, -hh for long
-H ([var]) display variable
-i [file] run script file
-I [file] run script file before the file is opened
-k [OS/kern] set asm.os (linux, macos, w32, netbsd, ...)
-l [lib] load plugin file
-L list supported IO plugins
-m [addr] map file at given address (loadaddr)
-M do not demangle symbol names
-n, -nn do not load RBin info (-nn only load bin structures)
-N do not load user settings and scripts
-q quiet mode (no prompt) and quit after -i
-Q quiet mode (no prompt) and quit faster (quickLeak=true)
-p [prj] use project, list if no arg, load if no file
-P [file] apply rapatch file and quit
-r [rarun2] specify rarun2 profile to load (same as -e dbg.profile=X)
-R [rr2rule] specify custom rarun2 directive
-s [addr] initial seek
-S start r2 in sandbox mode
-t load rabin2 info in thread
