File Properties Identification

File type identification is done using -I. With this option, rabin2 prints information on a binary's type, its encoding, endianness, class, operating system, etc.:

$ rabin2 -I /bin/ls
file    /bin/ls
type    EXEC (Executable file)
pic false
has_va  true
root    elf
class   ELF64
lang    c
arch    x86
bits    64
machine AMD x86-64 architecture
os  linux
subsys  linux
endian  little
strip   true
static  false
linenum false
lsyms   false
relocs  false
rpath   NONE

To make rabin2 output information in format that the main program, radare2, can understand, pass -Ir option to it:

$ rabin2 -Ir /bin/ls
e file.type=elf
e cfg.bigendian=false
e asm.os=linux
e asm.arch=x86
e anal.arch=x86
e asm.bits=64
e asm.dwarf=true