[b]Problem: MAIN array (my @Sort_Order) gets corrupted by subroutine that does not touch the array???

Process:
- open(MAIN_IFH,$IFH); # in main
- split 1st column and store values in my @Sort_Order.


Here’s where it gets crazy:
- loop thru @Sort_Order using $line-count
- @Sort_Order gets corrupted where I exit the loop. ie ( line-count == 6 ) -> (Value 6 gets corrupt) by &Why_Does_This_Happen();

&Why_Does_This_Happen():
- The open(WHY_IFH,$IFH);
- while( <WHY_IFH> ) { last; } currputs @Sort_Order

- If open(WHY_IFH,$empty); is an empty >> value wiull be null -> 6) ::
- If open(WHY_IFH,$IFH); value 6) has the unsplit data record in IFH;


======================== Printed from &Why_Does_This_Happen(); ===================================
Before while( <WHY_IFH> ): @Sort_Order = ARRAY(0x65cfb0)
1) :111:
2) :222:
3) :333:
4) :444:
5) :555:
6) :666:
7) :777:
8) :888:
9) :999:
After while( <WHY_IFH> ): @Sort_Order = ARRAY(0x65cfb0)
1) :111:
2) :222:
3) :333:
4) :444:
5) :555:
6) :111 , 03-01-23 => 211 32
:
7) :777:
8) :888:
9) :999:

========================== Perl Script =========================================
use strict;
use v5.28.1;

our $Ref_Sort_Order;
our $IFH = 'INPUT_FILE.TXT';
open(MAIN_IFH,$IFH);

my (@Sort_Order,$line_number);
while ( <MAIN_IFH> ) {
my ($phoneNum) = split;
push(@Sort_Order,$phoneNum);
}
close IFH;

$Ref_Sort_Order = \@Sort_Order; # Ref to use for print only
my $lineCount;

foreach( @Sort_Order ) {
if( ++$lineCount == 6 ) { &Why_Does_This_Happen(); exit; }
}

#-----------------------------------------------------------------------------------------------
sub Why_Does_This_Happen {
open(WHY_IFH,$IFH) or die $!;
Print_Array("Before while( <WHY_IFH> ): \@Sort_Order = $Ref_Sort_Order\n");

while( <WHY_IFH> ) { last; }
close WHY_IFH;

Print_Array("After while( <WHY_IFH> ): \@Sort_Order = $Ref_Sort_Order\n");
return;
}
#-----------------------------------------------------------------------------------------------
sub Print_Array {
my $ofh = 'test.txt';
open(OFH,">$ofh");

my $msg = shift;
say OFH $msg;

my $line;
foreach( @$Ref_Sort_Order ) {
$line = ' ' x (3 - length(++$line)) . $line;
say OFH "$line) :$_:";
}

close OFH;
system($ofh);
return;
}

========================== INPUT_FILE.TXT =====================================
111 , 03-01-23 => 211 32
222 , 03-02-23 => 222 40
333 , 03-03-23 => 233 101
444 , 03-04-23 => 244 113
555 , 03-35-23 => 255 104
666 , 03-06-23 => 266 34
777 , 03-07-23 => 277 119
888 , 03-08-23 => 288 116
999 , 03-09-23 => 299 28

========================== Printed from MAIN: if( lineCount < 6 ) { ==========================

1) :111 , 03-01-23 => 211 32
:
2) :111 , 03-01-23 => 211 32
:
3) :111 , 03-01-23 => 211 32
:
4) :111 , 03-01-23 => 211 32
:
5) :111 , 03-01-23 => 211 32
:
6) :666:
7) :777:
8) :888:
9) :999:

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