UNIX for Dummies Questions & Answers

I have searched to find an anwer to no avail, I hope you can help me.
I have a.ksh that many people call and a.ksh calls b.ksh

b.ksh is also invoked stand-alone by many people as well

In b.ksh I want to do something different if it was not involked by a.ksh.

How can I do this?

Believe you can check the following vars..

$$ = The PID number of the process executing (this might return the PID of that script not the parent, I dont remember)

I havnt tried it, but I think it would work.

or

you can call it from a.ksh and pass a param to b.ksh and check for that param

Here is how to get the Parent id: https://www.unix.com/shell-programmin...shell-pid.html

So, I guess the PID and the PPID are always going to be different. I thought I could tell if someone had launched b.ksh directly or if b.ksh was called from a.ksh. I think I will need to check the name of the program for the PPID and compare it to a local variable in b.ksh. Does anyone know how to get the program name for the PPID on Unix Solaris?

Can someone please help me?
I have the following command that gets me what I need on the command line
ps -ef| awk '$2 == 9999 {print $8}' # where 9999 is my current sessions PPID

When I try to put it into my Korn shell it does not behave the same way:
my_var=`ps -ef| awk '$2 == $PPID {print $8}'`

You need to fix the quoting, the $PPID is not getting expanded inside single quotes.

Code:

my_var=`ps -ef | awk '$2 == '"$PPID"' { print $8 }'`

Maybe there's an option to ps to say which PIDs you want; it's available on Linux at least.

Thank you so much, that worked, I really appreciate your help.

Many awk implementations also allow passing shell variables, either via the -v option, or as trailing argument (after the file to parse).
So you could probably avoid some quoting trouble by e.g.
Since you are on Solaris the awk there knowing this option might be in /usr/xpg4/bin
while the /usr/bin awk could be a little more dumb.

Code:

$ ps -ef | awk -v ppid=$PPID '$2==ppid {print $8}'

But I think you could further improve by setting up your own format instead of relying on -f
which may change between different ps implementations.
Just tell ps what fields you are interested in.
e.g.

Code:

cmd=`ps -e -o ppid= -o comm= | awk -v ppid=$PPID '$1==ppid {print $2}'`

Note, that this would only capture the command.
If you need the command line including arguments substitute -o comm= by -o args=.
Unfortunately, I haven't access to a Solaris box right now, and I don't know by heart.
So I may be wrong, but I think to remember that Solaris also has a pgrep command similar to that found on Linux (I would suggest to refer to man pgrep)
Another, often working way (except in C-shell compatibles (well except on FreeBSD yet where it even works in csh)) is to simply refer to $0 for the current shell, and $- for its arguments.
Then you also might be interested to note that Solaris has a ptree command
similar to pstree on Linux, which will list a process hierarchy tree that could be parsed.
And Solaris even has a rudimentary procfs with a set of accompanying p* commands (like ptree above).
As said, I am only recapitulating this without a system to verify at hands.
Therefore, please check the man pages.