Dtrace print parent process command

Question

I'd like to have a script that for each new running process, prints its starting command, as well as its parent process.

i'm using the following probes :

proc::posix_spawn:exec-success,proc::__mac_execve:exec-success

From within the script body, command line string is built from curproc->p_dtrace_argv.

parent pid (ppid) is also available, but so far I haven't managed to figure out how to extract the parent process name (preferably full name that can be taken from parent argv[0]).

Answer 1

You can capture the execname of the process prior to the call to exec() in the proc:::exec probe. That will be the name of the executable that called fork() and will match the execname of the parent process.

I tested this on a Solaris 11 installation:

#!/usr/sbin/dtrace -s

proc:::exec
{
    self->pexecname = execname;
}

proc:::exec-success
/ self->pexecname != 0 /
{
    printf( "execname: %s, parent execname: %s", execname, self->pexecname );
    self->pexecname = 0;
}

It produced the following output:

dtrace: script './exec.d' matched 2 probes
 CPU     ID                    FUNCTION:NAME
   6  12486         exec_common:exec-success execname: utmp_update, parent execname: gnome-pty-helper
  14  12486         exec_common:exec-success execname: bash, parent execname: gnome-terminal
  15  12486         exec_common:exec-success execname: ls, parent execname: bash

Updated per comments:

#!/usr/sbin/dtrace -s

proc:::exec
{
    self->pexecname = execname;
    self->parent_args = (build parent args off curproc here)
}

proc:::exec-success
/ self->pexecname != 0 /
{
    printf( "execname: %s, parent execname: %s", execname, self->pexecname );
    self->pexecname = 0;
    self->parent_args = 0;
}

proc:::exec-failure
/ self->pexecname != 0 /
{
    self->pexecname = 0;
    self->parent_args = 0;
}