There is no way to pass the output of a gdb command to a shell
command. For example, something similar is not permitted: "(gdb)
thread apply all bt | vim -". This kind of feature is quite helpful in
a scenario where a program under debugger has 100s of threads running
and one wants to search a particular pattern in stack-traces. I have
implemented a feature which will allow one to pass the output of any
gdb command to any shell command.

2011-07-09 Abhijit Halder <abhijit.k.halder@symantec.com>

    * top.c (execute_command_to_pipe): New function.
     (execute_command): Update.
    * ui-file.c (gdb_modify_io): New function.
    * ui-file.h (gdb_modify_io): Add prototype.