Hello james28909,

the possibility entirely depends on the executable: it accepts input? some program accept input on their STDIN, others ignore it. For example firefox does not accepts inputs: 
 perl -e "print 'www.perlmonks.org'"| "C:\Program Files (x86)\Mozilla 
+Firefox\firefox.exe"

[download]
produce nothing but de default firefox page opened in a new instance of the program.
grep (i use the win32 port) by other hand, it accepts things in input: 
perl -e "print 'www.perlmonks.org'"| grep w
www.perlmonks.org

perl -e "print 'www.perlmonks.org'"| grep XXXX

[download]
Some program accept some filename as data file, so you can let your Perl's program write such datafile: 

 perl -e "open $fh,'>','perlcreated.txt' or die" && notepad perlcreate
+d.txt

[download]
When notepad is called the file yet exists.
Or the executable can accept data on a specific port, listening on a socket opened on that port, like a webserver...

There are a lot of possibilities but they all depends on the executable behaviour: it has some ear? or is deaf and dull?

L*

UPDATE: note the the term 'parent program' is a little misleading: parent and child parallel is used when a program spwan some other process, possibly with the intention to comunicate eachothers: the program is one but procesess can be many.

L*
There are no rules, there are no thumbs..
Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.

In reply to Re: Returning data to parent program by Discipulus
in thread Returning data to parent program by james28909

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