opendir & grep:

opendir(DIR,"$SCANDATA");
@files = sort(grep(/[0-9]*\.[0-9]*\-/,readdir(DIR)));
closedir(DIR);

foreach:

 foreach $FILE (@FILES) { }

hash iteration:

while (($key,$val) = each (%hash)) { } 

referencing a subroutine:

$SUBNAME = "junk";
&$SUBNAME(@PARAMETERS); 

capitalizing:

word: $foo = ucfirst lc $foo;

each word: $foo =~ s/(\w+)/\u\L$1/g;

passing array/hash by reference

sub test {

local(*OPTS,*USERSET,*FIELDS) = @_;

..... }

&test (\%options,\%USERLIST,\@FIELDLIST);

select output

$OLDFH = select();

open(TXT,"> report.txt");
select(TXT);

....

select($OLDFH);

getopt

use Getopt::Std;

%options=();
getopts("he:f:s:SD:u:F:",\%options);

if ($options{h}) { &usage(); }

Parsing Directory & File Names:

    use File::Basename;

    ($name,$path,$suffix) = fileparse($fullname,@suffixlist)
    fileparse_set_fstype($os_string);
    $basename = basename($fullname,@suffixlist);
    $dirname = dirname($fullname);

    ($name,$path,$suffix) = fileparse("lib/File/Basename.pm","\.pm");
    fileparse_set_fstype("VMS");
    $basename = basename("lib/File/Basename.pm",".pm");
    $dirname = dirname("lib/File/Basename.pm");

fileparse - split a pathname into pieces

basename - extract just the filename from a path

dirname - extract just the directory from a path

optimal byte units (from here)

sub utils_convert_bytes_to_optimal_unit{
  my($bytes) = @_;

  return '' if ($bytes eq '');

  my($size);
  $size = $bytes . ' Bytes' if ($bytes < 1024);
  $size = sprintf("%.2f", ($bytes/1024)) . ' KB' if($bytes >= 1024 && $bytes < 1048576);
  $size = sprintf("%.2f", ($bytes/1048576)) . ' MB' if($bytes >= 1048576 && $bytes < 1073741824);
  $size = sprintf("%.2f", ($bytes/1073741824)) . ' GB' if ($bytes >= 1073741824 && $bytes <1099511627776);
  $size = sprintf("%.2f", ($bytes/1099511627776)) .' TB' if ($bytes >= 1099511627776);

  return $size;
}