perl hash mapping/retrieval issues with split and select columns - perl

Question

Perl find and replace multiple(huge) strings in one shot
P.S.This question is related to the answer for above question.
When I try to replace this code:
Snippet-1
open my $map_fh, '<', 'map.csv' or die $!;
my %replace = map { chomp; split /,/ } <$map_fh>;
close $map_fh;
with this code:
Snippet-2
my %replace = map { chomp; (split /,/)[0,1] } <$map_fh>;
even though the key exists (as in the dumper), exists statement doesn't return the value for the key.
For same input file, it works perfectly with just split alone (Snippet-1) whereas not returning anything when i select specific columns after split(Snippet-2).
Is there some integer/string datatype mess-up happening here?
Input Mapping File
483329,Buffalo
483330,Buffalo
483337,Buffalo
Script Output
$VAR1 = {
'483329' => 'Buffalo',
'46546' => 'Chicago_CW',
'745679' => 'W. Washington',
};
1 search is ENB
2 search is 483329 **expected Buffalo here**
3 search is 483330
4 search is 483337
Perl Code
open my $map_fh, '<', $MarketMapFile or die $!;
if ($MapSelection =~ /eNodeBID/i) {
my %replace = map { chomp; (split /,/)[0,1] } <$map_fh>;
use Data::Dumper;
print Dumper(\%replace);
}
close $map_fh;
my $csv = Text::CSV->new({ binary => 1, auto_diag => 1, eol => $/,quote_space => 0 });
my $tmpCSVFile = $CSVFile."tmp";
open my $in_fh, '<', $CSVFile or die $!;
open my $out_fh, '>', $tmpCSVFile or die $!;
my $cnt=1;
while (my $row = $csv->getline($in_fh)) {
my $search = $row->[5];
$search =~ s/[^[:print:]]+//g;
if ($MapSelection =~ /eNodeBID/i) {
$search =~ s/(...)-(...)-//g;
$search =~ s/\(M\)//g;
}
my $match = (exists $replace{$search}) ? $replace{$search} : undef;
print "\n$cnt search is $search ";
if (defined($match)) {
$match =~ s/[^[:print:]]+//g;
print "and match is $match";
}
push #$row, $match;
#print " match is $match";
$csv->print($out_fh, $row);
$cnt++;
}
# untie %replace;
close $in_fh;
close $out_fh;

Answer 1

You have a problem of scope. Your code:
if ($MapSelection =~ /eNodeBID/i) {
my %replace = map { chomp; (split /,/)[0,1] } <$map_fh>;
use Data::Dumper;
print Dumper(\%replace);
}
declares %replace within the if block. Move it outside so that it can also be seen by later code:
my %replace;
if ($MapSelection =~ /eNodeBID/i) {
%replace = map { chomp; (split /,/)[0,1] } <$map_fh>;
use Data::Dumper;
print Dumper(\%replace);
}
Putting use strict and use warnings at the top of your code helps you find these kinds of issues.
Also, you can just use my $match = $replace{$search} since it's equivalent to your ?: operation.

Answer 2

Always include use strict; and use warnings; at the top of EVERY perl script. If you had done that and been maintaining good coding practice with declaring your variables, you would've gotten error:
Global symbol "%replace" requires explicit package name at
That would've let you know there was a scoping issue with your code. One way to avoid that is to use a ternary in your initialization of %replace
my %replace = ($MapSelection =~ /eNodeBID/i)
? map { chomp; (split /,/)[0,1] } <$map_fh>
: ();