Facing challenge in making some changes in GDB for my personal project

Hi,
This is my first message in this mailing group. I am pretty new to gdb code
base. I am thinking of implementing something similar to findcrypt in IDA
pro in GDB. I first tried to script it in python but it took so long that
it is impractical. So, I decided to get the GDB source and make a few
modifications such that I can add a new command(like run,step etc..) which
does the same.
This command has two parts: It should do a single step execution. After
each step, I should disassemble the current instruction and find if any
crypto constants are used.
I am facing difficulty in disassembling the instructions. As far as I
analysed the source code, there is no option for returning the disassembled
information as some kind of object to caller. All that is available is
functions which can print the disassembled instruction. So, I would like to
know how I could get the disassembled instruction as some kind of object,
which I can use for future analysis.
Thank you in advance for any help.

Regards,
G.Krishnan.