How do I find what processes (with args) are being run on OS X (Leopard) during a period of time?

I am trying to find out what processes a particular process is exec'ing on an OS X machine (including arguments). I have not used DTrace before, but thought it should be trivial. After looking around for examples, I found this, which looks exactly like what I want:

$ sudo dtrace -n 'proc:::exec-success { trace(curpsinfo->pr_psargs); }'

Only, it doesn't work properly. One of the sites that listed that command had sample output which looked perfect, but when I try to run it on OS X, I get the following:

dtrace: description 'proc:::exec-success ' matched 2 probes
CPU     ID                    FUNCTION:NAME
  0  18616         posix_spawn:exec-success 
             0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f  0123456789abcdef
         0: 6d 64 77 6f 72 6b 65 72 00 73 6b 00 00 00 00 00  mdworker.sk.....
        10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
        20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
        30: 00 00 00 00 70 e5 20 0a 00 00 00 00 01 00 00 00  ....p. .........
        40: 00 00 00 00 00 00 00 00 00 00 00 00 cc 42 1c 0a  .............B..

  0  18610        __mac_execve:exec-success 
             0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f  0123456789abcdef
         0: 67 2b 2b 2d 34 2e 30 00 61 73 6b 00 00 00 00 00  g++-4.0.ask.....
        10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
        20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
        30: 00 00 00 00 e0 e1 20 0a 00 00 00 00 01 00 00 00  ...... .........
        40: 00 00 00 00 00 00 00 00 00 00 00 00 8c 4d 7b 0b  .............M{.

  0  18610        __mac_execve:exec-success 
             0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f  0123456789abcdef
         0: 69 36 38 36 2d 61 70 70 6c 65 2d 64 61 72 77 69  i686-apple-darwi
        10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
        20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
        30: 00 00 00 00 e0 e1 20 0a 00 00 00 00 01 00 00 00  ...... .........
        40: 00 00 00 00 00 00 00 00 00 00 00 00 14 8a 7b 0b  ..............{.

  3  18610        __mac_execve:exec-success 
             0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f  0123456789abcdef
         0: 63 6f 6c 6c 65 63 74 32 00 70 70 6c 65 2d 64 61  collect2.pple-da
        10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
        20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
        30: 00 00 00 00 f0 e3 20 0a 00 00 00 00 01 00 00 00  ...... .........
        40: 00 00 00 00 00 00 00 00 00 00 00 00 78 70 7b 0b  ............xp{.

i.e. only argv[0] is shown with random rubbish after it. Also, if argv[0] is longer than 16 characters, it's truncated!

Is there a way to get DTrace to do what I want on OS X? Or is there some other way to find the commands and args being called by something on OS X?

Thanks.

Solution 1:

Snow Leopard ships with a DTrace sample script called /usr/bin/newproc.d. It does want you want - however only globally. To restrict it to a single process you could try something like this:

cp /usr/bin/newproc.d ~/newproc.d

Add a new predicate by changing the following lines

19: proc:::exec-success
20: {

into this:

19: proc:::exec-success
20: / ppid == $target /
21: {

Now execute the new script like this:

sudo ~/newproc.d -p <PID>

PID is the process id of the process to watch. Please tell me if this works for you. I have only tested this briefly with a bash process.