Perl Weekly Challenge #45 Task #2, Source Dumper

Perl Weekly Challenge #45 Task #2: Source Dumper

The Source Dumper dumps the source code of itself. For my Blog of the PWC I use syntax highlighting. The perl program I use for the syntax highlighting I included in the Source Dumper of my Perl5 solution. This is a simple add-on with Text::VimColor.

Some highlights:

Perl5, Perl6 and Python solution.
Syntax Highlighting with Text::VimColor.
Program name with $0, $*PROGRAM and __file__
Simple line by line file reading.

Download and References

Download File: Perl5 Solution PWC #45 Task #2 ch-2.pl
Download File: Perl6 Solution PWC #45 Task #2 ch-2.p6
Download File: Python Solution PWC #45 Task #2 ch-2.py

Here I found the $*PROGRAM variable for Perl6:
docs.perl6.org: Variables

SYNOPSIS

 # ./ch-2.pl            - Execution of program
 # ./ch-2.pl help       - Help on parameters
 # ./ch-2.p6            - Execution of program
 # ./ch-2.py            - Execution of program

 # ./ch-2.pl | diff - ch-2.pl   - Should result in no difference
 # ./ch-2.p6 | diff - ch-2.p6
 # ./ch-2.py | diff - ch-2.py

 # perldoc ch-2.pod             - POD

Definition Task #2: Source Dumper

Write a script that dumps its own source code. For example, say, the script name is ch-2.pl then the following command should returns nothing.

 $ perl ch-2.pl | diff - ch-2.pl

Perl5

The printing of the Source Code is done with open(IN,$0) the file, a while loop while(IN) { print; } together with print and to close the file. Here the program name is in var $0.

The biggest part of the code is not needed for the PWC. It is a Source Dumper in HTML with Syntax Highlighting. This is done with the module Text::VimColor rather easy. You can print a full HTML page or only the source code part of the HTML. Some extra code is spent for the line numbers. Allthough Text::VimColor has an option for line numbers, it did not work. So I added the line numbers for myself.

Source Code

This is the code part needed for PWC, like described above:

 35     open(IN,$0) or die "Cant open $0\n";
 36     while(<IN>) { print; }
 37     close IN;

Some Highlights are:

Text::VimColor for Synthax Highlighting.
$0 for the program name,
while(IN) for the loop,

 Perl5 
  1 #!/usr/bin/perl
  2 
  3 use strict;
  4 use warnings;
  5 use Text::VimColor;
  6 
  7 if($ARGV[0] and $ARGV[0] eq "help") {
  8 	print "\n$0 - PWC #45 Task #2: Source Dumper\n";
  9 	print "\n";
 10 	print "    This source code dumper dumps its own source code, but also the \n";
 11 	print "    source code of other files with syntax highlighting using Text::VimColor.\n";
 12 	print "\n";
 13 	print "    ./ch-2.pl [<command|file>] [<full>]\n";
 14 	print "       command - help|high\n";
 15 	print "       file    - filename of file to dump.\n";
 16 	print "       full    - dump full html page not only source code.\n";
 17 	print "\n";
 18 	print "  Examples:\n";
 19 	print "    ./ch-2.pl           - Dumps own source code\n";
 20 	print "    ./ch-2.pl help      - This Usage information\n";
 21 	print "    ./ch-2.pl high      - Syntax high for ch-2.pl\n";
 22 	print "    ./ch-2.pl ch-1.pl   - Syntax high for ch-1.pl\n";
 23 	print "    ./ch-2.pl high 1    - Syntax high for ch-2.pl in full html page.\n";
 24 	print "    ./ch-2.pl ch-1.pl 1 - Syntax high for ch-1.pl in full html page.\n";
 25 	print "    ./ch-2.pl | diff - ch-2.pl - PWC 45 Task #2\n";
 26 	print "\n";
 27 }
 28 elsif($ARGV[0] and $ARGV[0] eq "high") { 
 29 	syntax_high($0,$ARGV[1]); 
 30 }
 31 elsif($ARGV[0]) { 
 32 	syntax_high(@ARGV); 
 33 }
 34 else { 
 35 	open(IN,$0) or die "Cant open $0\n";
 36 	while(<IN>) { print; }
 37 	close IN;
 38 }
 39 
 40 sub syntax_high {
 41 	my ($file,$full) = @_;
 42 	
 43 	# Option $full is for Debug Reasons, a Full HTML Page is created.
 44 	if(! $full) { $full = 0; }
 45 	
 46 	my $syntax = Text::VimColor->new(
 47 		file => $file,
 48 		filetype => 'perl',
 49 		html_full_page => $full,
 50 		# Extra vim options do not work: I want to have the line number
 51 		# in the source code and also to try different colorschemes for vim.
 52 		# extra_vim_options => [ "+set number", "+color darkblue" ],
 53 	);
 54 	
 55 	my $html = $syntax->html;
 56 	
 57 	my ($html1,$html2); # Full Page needs to be splitted, to get line numbers on each line.
 58 	if($full) {
 59 		my $tmp;
 60 		($html1,$tmp)  = split("<pre>",$html);
 61 		($html,$html2) = split("</pre>",$tmp);
 62 	}
 63 	
 64 	my @lnes = split("\n",$html); # Every line for Line Number
 65 	
 66 	if($full) { print $html1, "<pre>\n"; } # Print first part of full page
 67 	my $cnt = 1;               # Count line number
 68 	foreach my $line (@lnes) { # Every line for Line Number
 69 		printf("%3d %s\n",$cnt,$line); # Print Line with Line Number
 70 		$cnt++;
 71 	}
 72 	if($full) { print "</pre>\n", $html2; } # Print last part of full page
 73 }

Perl6

I translated the necessary part for PWC to Perl6. And let me mention some parts different to Perl5 here. May-be things could be solved easier? But for me as a beginner in Perl6, this is what I found first.

$*PROGRAM for the program name.
my $fh = open :r, $*PROGRAM; In Perl6 are used attributes with double-colons everywhere, here ":r". This can become difficult for me to swallow.
while ( ! $fh.eof; ) { While loop asks for not eof().
$str = $fh.get; And get reads without newline.

 Perl6 
  1 #!/home/chuck/rakudo/bin/perl6
  2 
  3 use strict;
  4 
  5 # print "ch-2.p6 - PWC #45 Task #2: Source Dumper\n";
  6 # print $*PROGRAM, ", ", $*PROGRAM-NAME, "\n";
  7 
  8 my $fh = open :r, $*PROGRAM;
  9 
 10 my $str;
 11 while ( ! $fh.eof; ) { 
 12 	$str = $fh.get;
 13 	$str.print; print "\n"; 
 14 }
 15 $fh.close;

Python

Because the code is not too complicated, let me mention some points. Put in mind that I am a beginner in Python, so any other Python programmer may wonder:

__file__ for the program name.
print(line), the comma at the end ommits newline. Otherwise newline is printed twice, first read from file and second an automatic newline from print.
for line in fh: I used a for loop, because this is what I found in the net.

 Python 
  1 #!/usr/bin/python
  2 
  3 # print "ch-2.pl (Version 1.0) PWC #42 Task #2: Balanced Brackets\n";
  4 # print "File:", __file__, "\n";
  5 
  6 fh = open(__file__);
  7 for line in fh:
  8 	print(line),
  9 
 10 fh.close

AUTHOR

Chuck

Perl Weekly Challenge #45 Task #2, Source Dumper