#!/usr/bin/perl
use strict;
use warnings;

my $str = "item1  | item2| item3 
|item4|
 ";

my @cleaned1 = map { clean_modify($_) } split( /\|/, $str );
my @cleaned2 = grep { clean_modify($_) } split( /\|/, $str );

print join "\n", @cleaned1;
print join "\n", @cleaned2;

sub clean_modify {
    $_[0] =~ s/^\s+?|\s+?$//g;
    return $_[0];
}

sub clean {  ## don't use
    chomp( $_[0] );
    $_[0] =~ s/^\s+//g;
    $_[0] =~ s/\s+$//g;
}