#!perl
#
use warnings;
use strict;
my @Sachen;

open(FH1,"<","bla1.txt",FH2,"<","bla2.txt",FH3,"<","bla3.txt",FH4,"<","bla4.txt");

open(OUTDATEN, ">>" , "blagesamt.txt" ) or die "Fehler beim oeffnen/anlegen: $!";
@Sachen = <FH1>,<FH2>,<FH3>,<FH4>;
foreach (@Sachen)
{
 print OUTDATEN (@Sachen);
       print OUTDATEN "\n"; 
}
  close (OUTDATEN) or die "kann nicht schließen blagesamt $!";
close () or die "kann nicht schließen bla1 $!";

#!/usr/bin/perl

use strict;
use warnings;

my @files = qw(bla1.txt bla2.txt bla3.txt bla4.txt);
my $output = 'blagesamt.txt';

for my $file(@files){
    open(my $fh,'<',$file) or die $!;
    open(my $write_fh,'>>',$output) or die $!;
    while(my $line = <$fh>){
        print $write_fh $line;
    }
    close $write_fh or die $!;
    close $fh;
}