What happend with parent process.

[krieger]

What happend with parent proces.
Two scripts:

perl4:

#
# loop operations
#
use strict;
my @food;
my $morsel;
my $TableLength;
my $i;
@food = ("pear", "plum", "egg", "apple");
#
# Table printing
#
$TableLength = $#food;
print $TableLength;
foreach $i (@food){
    print $i."\n";
}
do
{
    print "Password?";
    $a = <STDIN>;
    chop $a;
}
while ($a ne "fred");

perl5:

# Variable declaration
my $FileName = "perl4.pl";
my $Line = "";
my @Table;
my $pid;
 
$pid = system $FileName;
 
if(not defined $pid){
#child
   print "no resources";
}elsif($pid == 0)
{   
    print "I am a child";
    STDOUT->autoflush();
    sleep(5);
    print "I am a child2\n";
}else{
    print "I am a parent";
    STDOUT->autoflush();
}

printout:
prear
plum
egg
apple
Password?fred
I am a childI am a child2

And I have no output from parent process. Can anybody explain me why?

[KevinADC]

In your program, $pid is the return value of the system() function, which is the value of wait(), which is the value of the deceased forked process, which must be 0 (zero) judging by the behavior of your program. You are also using the autoflush() method without loading the IO::Handle module, which should cause your script to abort.

See, your program is not checking if a process is a child or a parent, it is only checking the return value of the system() function.