> The complexity/difficulty of getting DTrace probes implemented depends
> on the type of probe. AFAIK the degree of difficulty looks like this
> ("1"=easy, "10"=godlike knowledge of universe required):
>
> 1. "xtrace" probe (just prints what the "xtrace" mode of the shell would
> print)
Why is it useful to duplicate the functionality already provided by xtrace
mode?
> 2. Trace subprocess creation and exit (e.g. fork())
Can't DTrace do it now using existing probes?
> 3. Trace subshell creation and destruction (subshell!=child process in
> ksh93)
Ditto.
> 4. Trace shell function calls
This seems like a real value for any interpreted language.
> 5. Trace calls to external commands and builtin commands
For builtins - yes. For external commands existing facilities may be
sufficient.
- Alex Kolbasov
