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Parent forking multiple independent children
Interprocess Communication example from a Well House Consultants training course
More on Interprocess Communication [link]
Source code: breeder Module: P223

print "hello world\n";

# Start five child processes at intervals of 1 second

for (0..6) {
        $bill = (10,40,60,70,43,54,65)[$_];
        sleep 1;

# at this point, open a pipe if you want communication
# between parent and child via a stream after forking

        $john = fork();

# fork return false to child and child process id to parent

# child code

        if (! $john) {
                print "$bill Yum, yum\n";
                sleep 2;
                print "$bill Yum, yum, yum\n";
                sleep 4;
                print "$bill Yum, yum, YUMMY\n";

# parent code

        print "A child has been born, called $john \n";
        print "Keep rollin $bill along ... \n";


Sample output

wizard:pl graham$ perl breeder
hello world
A child has been born, called 199
Keep rollin 10 along ...
10 Yum, yum
A child has been born, called 200
Keep rollin 40 along ...
40 Yum, yum
10 Yum, yum, yum
A child has been born, called 201
Keep rollin 60 along ...
60 Yum, yum
40 Yum, yum, yum
A child has been born, called 202
Keep rollin 70 along ...
70 Yum, yum
60 Yum, yum, yum
A child has been born, called 203
Keep rollin 43 along ...
43 Yum, yum
70 Yum, yum, yum
A child has been born, called 204
Keep rollin 54 along ...
54 Yum, yum
10 Yum, yum, YUMMY
43 Yum, yum, yum
A child has been born, called 205
Keep rollin 65 along ...
65 Yum, yum
wizard:pl graham$ 40 Yum, yum, YUMMY
54 Yum, yum, yum
60 Yum, yum, YUMMY
65 Yum, yum, yum
70 Yum, yum, YUMMY
43 Yum, yum, YUMMY
54 Yum, yum, YUMMY
65 Yum, yum, YUMMY

Learn about this subject
This module and example are covered on our public Perl Extra course. If you have a group of three or more trainees who need to learn the subject, we can also arrange a private or on site course for you.

Books covering this topic
Yes. We have over 700 books in our library. Books covering Perl are listed here and when you've selected a relevant book we'll link you on to Amazon to order.

Other Examples
This example comes from our "Interprocess Communication" training module. You'll find a description of the topic and some other closely related examples on the "Interprocess Communication" module index page.

Full description of the source code
You can learn more about this example on the training courses listed on this page, on which you'll be given a full set of training notes.

Many other training modules are available for download (for limited use) from our download centre under an Open Training Notes License.

Other resources
• Our Solutions centre provides a number of longer technical articles.
• Our Opentalk forum archive provides a question and answer centre.
The Horse's mouth provides a daily tip or thought.
• Further resources are available via the resources centre.
• All of these resources can be searched through through our search engine
• And there's a global index here.

Web site author
This web site is written and maintained by Well House Consultants.

Purpose of this website
This is a sample program, class demonstration or answer from a training course. It's main purpose is to provide an after-course service to customers who have attended our public private or on site courses, but the examples are made generally available under conditions described below.

Conditions of use
Past attendees on our training courses are welcome to use individual examples in the course of their programming, but must check the examples they use to ensure that they are suitable for their job. Remember that some of our examples show you how not to do things - check in your notes. Well House Consultants take no responsibility for the suitability of these example programs to customer's needs.

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