Re: Script printing its own source code
> ... called quines ... And, in perl, one of the most amazing quine programs is Damian Conway's SelfGol. It's also the game of Life and a quine-izer for other programs - don't even think about looking at it. http://libarynth.f0.am/cgi-bin/twiki/view/Libarynth/SelfGOL I had the good fortune to sit in a nice enough bar, drinking beer (not the best idea considering) while he char by char worked his way through the script (it was an obfusticated perl submission). He includes evil things like stray parens/curlies so vi's '%' won't help you de-parse it and, even at a merer 1000 chars, managed to slip in useless code just to further befuddle. It was beyond humbling, made you want to give up even typing on a computer and go back to banging rocks and sticks together. a Andy Bach, Sys. Mangler Internet: [EMAIL PROTECTED] VOICE: (608) 261-5738 FAX 264-5932 self-reference, n. - See self-reference ___ Perl-Win32-Users mailing list Perl-Win32-Users@listserv.ActiveState.com To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs
RE: Script printing its own source code
Perl makes this even easier if the script is in a file... read from
filehandle 0 (stdin for perl.exe as opposed to <> which will be your
terminal rather than stdin).
---cut---
$x=q/test test test/;
open 0 or die('eek');
undef $/;
$a=<0>;
close (0);
print $a;
print "\n$x\n";
---cut---
Kind regards,
Mark Anderson
Service Improvement Programme
Level 2, 113 Dundas Street
Edinburgh, EH3 5DE
Tel: 0131 523 8786
Mob: 07808 826 063
> -Original Message-
> From: [EMAIL PROTECTED]
> [SMTP:[EMAIL PROTECTED] On Behalf Of
> Gardner, Sam
> Sent: Tuesday, May 31, 2005 1:58 PM
> To: '[EMAIL PROTECTED]'; Perl Mailing List
> Subject: RE: Script printing its own source code
>
> *** WARNING : This message originates from the Internet ***
>
>
>
> 1) H. . . Did you chomp?
>
> 2) I don't think there's any problem at all with a script opening itself
> as a text file. Keep in mind that when it's running it's been interpreted
> and is in memory (so no file sharing issue). It could, of course, destroy
> or modify itself. Whether you think that's a good thing or not depends on
> the purpose and methods of your script.
>
> Sam Gardner
>
> GTO Application Development
>
> Keefe, Bruyette & Woods, Inc.
>
> 212-887-6753
>
>
>
>
>
> -Original Message-
> From: Ted Schuerzinger [ <mailto:[EMAIL PROTECTED]>]
> Sent: Saturday, May 28, 2005 1:05 PM
> To: Perl Mailing List
> Subject: Script printing its own source code
>
>
> Over on rec.puzzles on Usenet (<[EMAIL PROTECTED]>), somebody
>
> posted a puzzle asking about using programming languages to print out a
> program's own source code. So, I quickly whipped up the following 11-line
>
> script in Perl:
>
>
> #! perl -w
>
> use strict;
>
> my $selfprint="c:/scripts/selfprint.pl";
>
> open SELFPRINT, "$selfprint" or die "Cannot open $selfprint for read :$!";
>
>
> while () {
> print;
> }
>
>
> I opened up the DOS prompt in Windows 98, and ran the script. The result
>
> was the following:
>
>
> Microsoft(R) Windows 98
> (C)Copyright Microsoft Corp 1981-1999.
>
> C:\WINDOWS>cd\scripts
>
> C:\scripts>perl selfprint.pl
> #! perl -w
>
> use strict;
>
> my $selfprint="c:/scripts/selfprint.pl";
>
> open SELFPRINT, "$selfprint" or die "Cannot open $selfprint for read :$!";
>
>
> while () {
> print;
> }
>
> C:\scripts>
>
>
> Two questions:
>
> 1) When the script prints itself out, it prints an extra blank line before
>
> giving me the command line again. (I've got the script open in my text
> editor, set to show line numbers, and there are definitely only 11
> lines.) Where's the blank line coming from?
>
> 2) Is it really a good idea for a script to be allowed to open itself? I
>
> don't know if I want to try having a script open itself for write, even if
>
> only to see what would happen. :-)
>
> --
> Ted Schuerzinger, [EMAIL PROTECTED]
> ___
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> To unsubscribe: <http://listserv.ActiveState.com/mailman/mysubs>
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RE: Script printing its own source code
Title: RE: Script printing its own source code
1) H. . . Did you chomp?
2) I don't think there's any problem at all with a script opening itself as a text file. Keep in mind that when it's running it's been interpreted and is in memory (so no file sharing issue). It could, of course, destroy or modify itself. Whether you think that's a good thing or not depends on the purpose and methods of your script.
Sam Gardner
GTO Application Development
Keefe, Bruyette & Woods, Inc.
212-887-6753
-Original Message-
From: Ted Schuerzinger [mailto:[EMAIL PROTECTED]]
Sent: Saturday, May 28, 2005 1:05 PM
To: Perl Mailing List
Subject: Script printing its own source code
Over on rec.puzzles on Usenet (<[EMAIL PROTECTED]>), somebody
posted a puzzle asking about using programming languages to print out a
program's own source code. So, I quickly whipped up the following 11-line
script in Perl:
#! perl -w
use strict;
my $selfprint="c:/scripts/selfprint.pl";
open SELFPRINT, "$selfprint" or die "Cannot open $selfprint for read :$!";
while () {
print;
}
I opened up the DOS prompt in Windows 98, and ran the script. The result
was the following:
Microsoft(R) Windows 98
(C)Copyright Microsoft Corp 1981-1999.
C:\WINDOWS>cd\scripts
C:\scripts>perl selfprint.pl
#! perl -w
use strict;
my $selfprint="c:/scripts/selfprint.pl";
open SELFPRINT, "$selfprint" or die "Cannot open $selfprint for read :$!";
while () {
print;
}
C:\scripts>
Two questions:
1) When the script prints itself out, it prints an extra blank line before
giving me the command line again. (I've got the script open in my text
editor, set to show line numbers, and there are definitely only 11
lines.) Where's the blank line coming from?
2) Is it really a good idea for a script to be allowed to open itself? I
don't know if I want to try having a script open itself for write, even if
only to see what would happen. :-)
--
Ted Schuerzinger, [EMAIL PROTECTED] ___
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Re: Script printing its own source code
Ted Schuerzinger wrote: > Over on rec.puzzles on Usenet (<[EMAIL PROTECTED]>), somebody posted > a puzzle asking about using programming languages to print out a program's > own source code. This is a classic programming challenge called "self-replicating program" or "quine". (Try Googling either of those.) The point of the challenge is that you are (sadly) *not* allowed to have the program simply read its own source code and echo it to output. The challenge is to write a program that will *programmatically* generate a new copy of itself. Quite a mind-bender if you think about it too much. The solution is easier in some languages than others. HTH David ___ Perl-Win32-Users mailing list Perl-Win32-Users@listserv.ActiveState.com To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs
RE: Script printing its own source code
Isn't that the easy part? (knowing the scriptname)? print "scriptname = ".$0."\n"; C:\perl\scripts>perl thisscript.pl scriptname = thisscript.pl -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chris Wagner Sent: Saturday, May 28, 2005 3:23 PM To: Perl-Win32-Users@listserv.ActiveState.com Subject: Re: Script printing its own source code That's just the Windows command prompt putting in a line before returning to the prompt. If u did it in Bash u could get it to not do that. But for the puzzle they were probably talking about making a script that printed itself without knowing it's own name ahead of time. -- REMEMBER THE WORLD TRADE CENTER ---=< WTC 911 >=-- "...ne cede males" 0100 ___ Perl-Win32-Users mailing list Perl-Win32-Users@listserv.ActiveState.com To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs ___ Perl-Win32-Users mailing list Perl-Win32-Users@listserv.ActiveState.com To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs
Re: Script printing its own source code
That's just the Windows command prompt putting in a line before returning to the prompt. If u did it in Bash u could get it to not do that. But for the puzzle they were probably talking about making a script that printed itself without knowing it's own name ahead of time. -- REMEMBER THE WORLD TRADE CENTER ---=< WTC 911 >=-- "...ne cede males" 0100 ___ Perl-Win32-Users mailing list Perl-Win32-Users@listserv.ActiveState.com To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs
Script printing its own source code
Over on rec.puzzles on Usenet (<[EMAIL PROTECTED]>), somebody
posted a puzzle asking about using programming languages to print out a
program's own source code. So, I quickly whipped up the following 11-line
script in Perl:
#! perl -w
use strict;
my $selfprint="c:/scripts/selfprint.pl";
open SELFPRINT, "$selfprint" or die "Cannot open $selfprint for read :$!";
while () {
print;
}
I opened up the DOS prompt in Windows 98, and ran the script. The result
was the following:
Microsoft(R) Windows 98
(C)Copyright Microsoft Corp 1981-1999.
C:\WINDOWS>cd\scripts
C:\scripts>perl selfprint.pl
#! perl -w
use strict;
my $selfprint="c:/scripts/selfprint.pl";
open SELFPRINT, "$selfprint" or die "Cannot open $selfprint for read :$!";
while () {
print;
}
C:\scripts>
Two questions:
1) When the script prints itself out, it prints an extra blank line before
giving me the command line again. (I've got the script open in my text
editor, set to show line numbers, and there are definitely only 11
lines.) Where's the blank line coming from?
2) Is it really a good idea for a script to be allowed to open itself? I
don't know if I want to try having a script open itself for write, even if
only to see what would happen. :-)
--
Ted Schuerzinger, [EMAIL PROTECTED]
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