= stack, stackv: examine call stack  *bind '#p' /prog* +*stack* [ *-v* ] [ *-p* _dispath_ _sblpath_ ]... _pid_ +*stackv* [ *-Tlm* ] [ *-r* _maxdepth_ ] [ _pid[._sym_] ...] ..._  _Stack_ writes to the standard output a stack trace for process _pid_,by decoding the stack traceback data contained in the file**/prog/**__pid__**/stack**__.__ The *-v* option causes _stack_ to printvalues of arguments and variables. The output is most useful when theLimbo program was compiled with the *-g* option to produce a *.sbl*symbol file. _Stack_ has a built-in list of associations between *dis* directoriesand their associated source directories (e.g. it can automatically mapfrom */dis/ls.dis* to */appl/cmd/ls.sbl*). Giving the *-p* option adds anew association to the head of this list: if a module path prefixmatches _dispath_, _stack_ will search for a symbol file in _sblpath_.If the environment variable *$sblpath* is set, pairs of items from itare added to the association list, as given as *-p* options. The *-p*options take precedence over *$sblpath*. _Stackv_ recursively traverses the symbols it finds, printing values asit goes. Repeated identical structure is not shown - only the pointervalue is printed, followed by *(qv)*. Each argument gives a startingpoint for the traversal, rooted by a process id, _pid_. If an unadornedprocess id is given, all values in all stack frames in the process willbe printed; adding names specifies the starting point. For instance,*123.init.ctxt.display* might specify the *display* field inside the*ctxt* adt inside the *init* function inside the process *123*. _Stackv_understands the following options: *-l*::  Show source line information with each item.*-m*::  Show module variables accessible from each stack frame.*-T*::  Do not show the Limbo types of value encountered.**-r**__ maxdepth__::  Restrict the maximum traversal depth to _maxdepth_ levels. == EXAMPLE Run _stack_ on process with ID 1: ....$ stack 1unknown fn() Module $Sys PC 742103waitfor() shnew.b:105.7, 38runpipeline() shnew.b:483.2, 14runit() shnew.b:552.3, 29init() shnew.b:83.3, 28.... The process is executing in the *Sys* module, a call to *sys->read* thatoriginated at line 105 (characters 7 to 38) of the *waitfor* function in*shnew.b*. Once again, with the *-v* option to reveal more: ....$ stack -v 1unknown fn() Module $Sys PC 742103waitfor(pid=18) shnew.b:105.7, 38        status=[0] ""        buf=[64] @b419a4        n=-1        who=-1runpipeline(ctx=nil, pipeline=@b41454) shnew.b:483.2, 14        pid=18runit(ctx=nil, pipes=nil) shnew.b:552.3, 29        pipeline=@b41454init(ctxt=nil, argv=nil) shnew.b:83.3, 28        buf=[1024] @b40f04        n=4        arg=@b41634        prompt=[21] "$ "$.... == FILES **/prog/**__pid__*/stack* +**/prog/**__pid__*/status* == SOURCE */appl/cmd/stack.b* +*/appl/cmd/stackv.b* == SEE ALSO _deb_(1), _ps_(1), _prog_(3), _debug_(2)