On Solaris we get the process's command line from /proc/pid/psinfo as struct psinfo. There are several issues with this approach.

1. pr_psargs member is only 80 bytes. Longer command lines are truncated by kernel.
2. The buffer contains the command line as it was when the process was started. It is not updated with up-to-date status information as set by zabbix_agentd, postgres and other long-running daemons.

/usr/ucb/ps looks directly at the process' memory to get up-to-date process titles.

Not sure if this is the approach that we want to take in Zabbix. We should document these limitations though.