Could you explain the code for a sec. Should those ! be /.

I can understand $string =~ s/(apples|oranges|bananas)/$replace{$1}/e would take the first match from string ($1). Then because the /e tag the second part in substitution would be value complement to the key ($1). What is the deal with the || (or?) statement. (I guess I'm mistaken with the ! elements) Would this (mine own )code work? 
 #!/usr/bin/perl -w
use strict;
use warnings;     

my @keys = qw(F29-2 F29-3 F29-4 F44-2 F53-2 F38-3 F12-2);
my @vals = qw(F29B2 F29B3 F29B4 F44B2 F53B2 F38B3 F12B2);
my %replace;
@replace{@keys} = @vals;


while (my $line = <>) {
    if($line =~ m/^\>/){my $name=$line;$name =~ s/(F29-2,F29-3,F29-4,F
+44-2,F53-2,F38-3,F12-2)/$replace{$1}/;print $name;}   
    elsif ($line!~m/^\>/){print $line;}
  }

[download]
Did not want to use some convoluted regexp patterns because they might be usable this time but not always. Want to learn the tehnique to do such list/hash substitutions as in original question.

In reply to Re^2: multiple substitution by naturalsciences
in thread multiple substitution by naturalsciences

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