dtrace discuss - Aug 2009 - How to print all parameters for a function (pid provider?)

Hi, dtrace experts:

Using pid provider, can we print all the parameters passed to a function?
First need to know is the number of parameters the function has.  But which
build in variable could show us the number of parameters?

Thanks,
Daniel
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On Wed, Aug 12, 2009 at 9:03 AM, Qihua Wu<dtrace.wu at gmail.com>
wrote:
> Hi, dtrace experts:
>
> Using pid provider, can we print all the parameters passed to a function?
> First need to know is the number of parameters the function has.? But which
> build in variable could show us the number of parameters?
Unfortunately, there''s currently no way to do that.  You need to know
the number of arguments to the function.

Note that DTrace is more than happy to print values for arguments that
don''t exist:

# dtrace -n ''pid$target::main:entry{printf("0x%x 0x%x 0x%x
0x%x\n",
arg0, arg1, arg2, arg3)}'' -c "ls /"
dtrace: description ''pid$target::main:entry'' matched 1 probe
bin       devices   home      media     opt       root      system    var
boot      etc       kernel    mnt       platform  rpool     tmp
dev       export    lib       net       proc      sbin      usr
dtrace: pid 107590 has exited
CPU     ID                    FUNCTION:NAME
  1  57031                       main:entry 0x2 0x8047dd0 0x8047ddc 0x8047d8c


#

Based on this, you could always just dump arg0 - arg9 and figure
things out after the fact.  (Assuming there are no more than 10
arguments to any function.)

Chad