simple

#!/usr/bin/perl -w
# GDSII generation 
#   Most simple example, have only one box-500 structure.
#   It has one boundary.

use GDS2;                                               # --- enable GDSII (GDS2) library
# strict checks variable declaration and subroutine argument consistency
use strict;
  
my $VERSION = "2018-09-03 06:30" ;                      # written by emacs time-stamp (UTC)
## --------------------------------------------
##          M A I N  R O U T I N E 
## --------------------------------------------
my ($gds2File);                                         # ---  file handle

#		出力名を 「自分の名前.gds」 に設定します。ただし、もし、 .txt が付いていたら、それは先に削除します。
my $filename = $0;					# ---  set filename with the same as this script
   $filename =~ s/\.txt$//;				# ---  Strip '.txt' part
							#      $ は行末を意味します
   $filename .= '.gds';		                        # ---  Add '.gds' to (output) filename
                                                        #      dot(.) connects string

$gds2File = new GDS2(-fileName=> '>'. $filename);       # ---  open new GDS2 (object) to write

$gds2File -> printInitLib(-name=>'LibraryName');        # --- always necessary for start
							#     名前は何でも良いです
$gds2File -> printBgnstr( -name=> 'box-500');           # --- Start new structure
$gds2File -> printBoundary(                             # --- Boundary with four coordinate
    -xy=>  [-250, -250,
             250, -250,
             250,  250,
            -250,  250],
    -layer=> 0,                                         # --- layer (省略可。その時は 0)
    );

$gds2File -> printEndstr();                             # --- End of this new structure
$gds2File -> printEndlib();                             # --- close library
__END__