How to concatenate values for duplicate hash keys in Perl? - perl

Question

I know it is not possible to have duplicate keys in a hash, but this is what my data looks like:
Key Value
SETUP_FACE_PROT great
SETUP_FACE_PROT great2
SETUP_FACE_PROT great3
SETUP_FACE_PROT great3
SETUP_ARM_PROT arm
SETUP_FOOT_PROT foot
SETUP_FOOT_PROT foot2
SETUP_HEAD_PROT goggle
I would like to concatenate values for repeated keys, separated by a * character. For example, this is what I want the output to look like:
SETUP_FACE_PROT'=great*great2*great3',
SETUP_ARM_PROT='arm',
SETUP_FOOT_PROT='foot*foot2',
SETUP_HEAD_PROT='google'
This is how I've tried to solve the problem so far:
foreach my $key ( sort keys %stuff )
{
print "$key=\'", join( "*", #{ $stuff{$key} } ), "\'\n";
}
But instead of printing the result, how can I store it in a variable so that I can pass it to another subroutine? I'm trying to create a new string that looks like this:
$newstring="
SETUP_FACE_PROT='great*great2*great3',
SETUP_ARM_PROT='arm',
SETUP_FOOT_PROT='foot*foot2',
SETUP_HEAD_PROT='google' "

Answer 1

You can't duplicate keys, you can create a hash of arrays.
#!/usr/bin/env perl
use strict;
use warnings;
use Data::Dumper;
my %stuff;
while (<DATA>) {
my ( $key, $value ) = split;
push( #{ $stuff{$key} }, $value );
}
print Dumper \%stuff;
foreach my $key ( sort keys %stuff ) {
print "$key=\'", join( "*", #{ $stuff{$key} } ), "\'\n";
}
__DATA__
SETUP_FACE_PROT great
SETUP_FACE_PROT great2
SETUP_FACE_PROT great3
SETUP_FACE_PROT great3
SETUP_ARM_PROT arm
SETUP_FOOT_PROT foot
SETUP_FOOT_PROT foot2
SETUP_HEAD_PROT goggle
Edit:
Turning it into a string as requested:
my $results;
foreach my $key ( sort keys %stuff ) {
$results .= "$key=\'". join( "*", #{ $stuff{$key} } ). "\'\n";
}
print $results;
Or perhaps using print still with a filehandle:
my $results;
open ( my $output, '>', \$results );
foreach my $key ( sort keys %stuff ) {
print {$output} "$key=\'", join( "*", #{ $stuff{$key} } ), "\'\n";
}
close ( $output );
print $results;

Answer 2

At last i got an answer doing this.
use Data::Dumper;
my %stuff;
use Text::CSV;
my $csv = Text::CSV_XS->new ({ binary => 1, eol => $/ });
my $filenamex = 'duplicate2.csv';
$checkstring ='';
open(my $datab, '<', $filenamex) or die "Could not open '$filename' $!\n";
$i=1;
my %datan;
while (my $linea = <$datab>)
{
chomp $linea;
#fieldsx = split ",",$linea;
$key = $fieldsx[0];
$value = $fieldsx[1];
# print $key;
push( #{ $stuff{$key} }, $value );
}
foreach my $key ( sort keys %stuff )
{
$checkstring = $checkstring.','.$key.'='. join( "*", #{ $stuff{$key} } );
}
print $checkstring;