[ale] Q: How can I capture a binary block with emacs/gdb?

[johnmills at speakeasy.net (John Mills)]

ALErs -

I'm debugging a Linux application with gdb running under emacs. My
application receives JPEG images that it caches in dynamically allocated
storage, telling me what it got, as in:
 Breakpoint 2, CINet::PostImg(int, int, lbuf) (this=0x805fa00, i=7,
 type=2, lBuf=
      {len = 9685, buf = 0x80d1a08 "????"}) at INet.cpp:435

I would like to write that 9685-byte block at 0x80d1a0a to a file and look
at it with a JPEG viewer. I haven't been able to find a promising command
combination for emacs and/or gbd to write off a binary block like that,
although it seems a reasonable thing to need sometimes.

Any help from you gurus to a grunt?

TIA.

 - John Mills
   john.m.mills at alum.mit.edu