Solaris

Hi,
i have a script which need to do behave differently when run as a startup process from init.d/ rc2.d script and when run manually from shell.
How do i distinguish whether my script is run by init process or by shell??

Will the command
/proc/$$/psinfo | grep "myscript" work well???
Problem is i can't reboot my system to verify it.

apptrace - for trace of library calls
dtrace - debugger, new in version 10
pargs - get list of arguments and environment variables with which process was started
pfiles - list of file descriptors, associated with process
pgrep - get the PID's of processes by name i.e. Something like ps -efl|grep -v grep|grep process_name
pkill - send signal to process. For example pkill -9 init :-P
pldd - list dynamic libraries, associated with process, similar to ldd for executable
plockstat - see list of locked by process files. Lock can be mutex i.e. exclusive and reader/writer for shared access
pmap - get memory map (segments) of process
preap - try to kick-off zombie process
prstat - fullscreen view of processes sorted by different criteria, similar to Linux top command
prun - continue hold with pstop process
ps - print process information and status. In Solaris exist SYSV and BSD variants, respectively /usr/bin/ps and /usr/ucb/ps
psig - list signals that can be handled by process
pstack - get backtrace stack of process for debugging purposes
pstop - temporary hold process
ptree - print the tree of processes
pwait - wait till process finish
pwdx - list working directory for process, like pwd command
truss - for trace system calls and signals