The core accepts multiple flags from the command line to change some configuration or start with different options.
Here's the help message:
$ radare -h
radare [options] [file]
-s [offset] seek to the desired offset (cfg.seek)
-b [blocksize] change the block size (512) (cfg.bsize)
-i [script] interpret radare or ruby/python/perl/lua script
-p [project] load metadata from project file
-l [plugin.so] link against a plugin (.so or .dll)
-e [key=val] evaluates a configuration string
-d [program|pid] debug a program. same as --args in gdb
-f set block size to fit file size
-L list all available plugins
-w open file in read-write mode
-x dump block in hexa and exit
-n do not load ~/.radarerc and ./radarerc
-v same as -e cfg.verbose=false
-V show version information
-u unknown size (no seek limits)
-h this help message