dominictarr/ps-tree — pull request #1 by fjakobs (2011-11-14 10:54:23+00:00)
Title: cmd is not supported on OSX and actually causes an error on Solaris:

```
$ ps -A -o ppid,pid,cmd
ps: unknown output format: -o cmd
usage: ps [ -aAdefHlcjLPyZ ] [ -o format ] [ -t termlist ]
[ -u userlist ] [ -U userlist ] [ -G grouplist ]
[ -p proclist ] [ -g pgrplist ] [ -s sidlist ] [ -z zonelist ] [-h lgrplist]
'format' is one or more of:
user ruser group rgroup uid ruid gid rgid pid ppid pgid sid taskid ctid
pri opri pcpu pmem vsz rss osz nice class time etime stime zone zoneid
f s c lwp nlwp psr tty addr wchan fname comm args projid project pset lgrp
```