# get_format holt sich über den namen der Datei das Format des document
sub get_format{
  use strict;
  use warnings;
  use File::Basename;
  my $suffix;
  my @files;
  my $name = shift;
  my $doc_format = shift;
  my $srcdir    =shift;
  
  foreach my $f (glob( $srcdir."$$name.*" ) ) {
    my ($basename, $path, $ext ) = fileparse ( $f, "\..+" );
    next if $ext =~ /(JPL|a00)$/;
    push( @files, $f ); 
  }
  
  foreach my $ele (@files){
    my @s = split(/\./,$ele);
    $$doc_format = $s[1];
  }
}

#> ls -1
file.doc
file.odt
file.txt
test.pl

#> cat test.pl
#!/usr/bin/perl
use strict;
use warnings;
use File::Basename;
use Data::Dumper;

sub get_format{
   my $suffix;
   my @files;
   my $name = shift;
   my $doc_format = shift;
   my $srcdir = shift;
 
   foreach my $f (glob( $srcdir."$name.*" ) ) {
     my ($basename, $path, $ext ) = fileparse ( $f, "\..+" );
     next if $ext =~ /(JPL|a00)$/;
     push( @files, $f );
   }

   foreach my $ele (@files){
     my @s = split(/\./,$ele);
     $doc_format = $s[1];
   }
   return \@files;
}

my $files = get_format('file', '', './');

print Dumper($files);

#> ./test.pl
$VAR1 = [
          './file.doc',
          './file.odt',
          './file.txt'
        ];

#!/usr/bin/perl

use strict;
use warnings;

my $test = 'Hallo';
test(\$test);
print $test;

sub test{
  my $ref = shift;
  $$ref = 'test';
}

~/entwicklung 173> perl ref.pl 
test