NAME    [Toc]    [Back]

     pmdb - debugger

SYNOPSIS    [Toc]    [Back]

     pmdb [-c core] [-p pid] program [...]

DESCRIPTION    [Toc]    [Back]

     The pmdb utility can be used to see what is happening inside
a running
     process or to catch program crashes and examine the state at
the time of
     the crash.  The only way to start pmdb at this moment is  to
specify the
     name  of the program to be debugged and all its arguments on
the command
     line.  Optionally, -c can be used to specify a core file  to
examine.  It
     is  also possible to debug a process that is already running
by specifying
     the process's PID to the -p flag.  This causes  the  process
to be put in
     STOPPED  state  until  execution is resumed either by an explicit command to
     pmdb or by exiting pmdb.  The program is controlled  from  a
command line
     which usually gives the prompt "pmdb>".

PROCESS STATES    [Toc]    [Back]

     A loaded program can be in one of three possible states:

     LOADED   This is the initial state.  The program is not running, it can't
              be examined (because it doesn't  have  any  state).
The only thing
              that can be done to the process is to start it with
the run command.


     RUNNING  When a process is RUNNING, the only way  to  affect
it is through
              signals  sent  to  it.   Unless a signal is ignored
with the signal
              ignore command, it will be caught by pmdb  and  the
process will
              go into the STOPPED state.

     STOPPED   A  stopped  process  can  be examined, changed and
restarted with
              the continue command.

COMMANDS    [Toc]    [Back]

     examine symbol|address
                   Fetch and display in hex a word at address  or
symbol.

     regs           Show  the contents of the processor registers
at the moment
                   the process was STOPPED.

     trace         Show the function call trace of the  currently
STOPPED process.


     run           Start running a LOADED process.

     continue      Continue a STOPPED process.

     kill          Unconditionally kills the debugged process and
puts it in
                   the LOADED state.

     signal ignore|stop signum|signame
                   Sets the signal state for the specified signal
to either
                   ignore  it  and  pass  it to the process or to
stop the process.


     sigstate      Shows which signals are currently ignored.

     setenv var val
                   Sets the environment variable var to the value
val.

     break symname|addr
                   Sets a breakpoint at the symbol symname or the
numerical
                   address addr.

     step          Resumes  execution  just  like  continue,  but
stops it again as
                   soon  as possible after executing at least one
instruction.

     sym_load fname offs
                   Loads a symbol table from the  file  fname  at
the offset
                   offs.

     help          Shows a short help.

     quit          Kills the process (if necessary) and exits.

     exit          Alias for quit.

SEE ALSO    [Toc]    [Back]

     core(5)

HISTORY    [Toc]    [Back]

     The  pmdb  debugger  was written because the author believed
that gdb(1) was
     too bloated and hairy to run on OpenBSD/sparc64.

BUGS    [Toc]    [Back]

     The command syntax is really poor and ad hoc at this moment.
Most of the
     command  names and arguments will change as soon as the command line interface
 is replaced.

OpenBSD     3.6                        February     20,      2002