#!/usr/bin/perl

print "Hello Monks";
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running the above code and grepping the process results in one process

CODE 2

#!/usr/bin/perl
use forks;
print "Hello Monks";
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running the above code and grepping the process results in two process.

You all are right, it is actually different process not threads. Now in the code 2, smaller process id is of main program and other process id is one when i write "use fork". Now i want to register a handle for 'SIGUSR2' for the process created by "use forks;"