Disassembling is the inverse action of assembling. Rasm2 takes hexpair as an input (but can also take a file in binary form) and show the human readable form.
To do this we can use the
-d option of rasm2 like this:
$ rasm2 -a x86 -b 32 -d '90' nop
Rasm2 also have the
-D flag to show the disassembly like
-d does, but includes offset and bytes.
In radare2 there are many commands to perform a disassembly from a specific place in memory.
You might be interested in trying if you want different outputs for later parsing with your scripts, or just grep to find what you are looking for:
Disassemble N instructions
Disassemble N bytes
Disassemble all instructions (seeking 1 byte, or the minimum alignment instruction size), which can be useful for ROP
pD, but using a simpler output.