Perl/OneLiners

The concise nature of [[Perl]] syntax permits miniscule yet powerful programs called "one liners" because they're easy to run from a command line. Line breaks have been added here.

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'''A simple web server that works with static and dynamic pages'''

perl -MIO::All -e 'io(":8080")->fork->accept->(

sub { $_[0] < io(-x $1 ? "./$1 |" : $1) if /^GET \/(.*) / })'

From [http://search.cpan.org/~ingy/IO-All/lib/IO/All.pod#DESCRIPTION http://search.cpan.org/~ingy/IO-All]

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'''Portscanner'''

perl -MIO::Socket -wle"map { IO::Socket::INET->new(qq($ARGV[0]:$_))

and print } 1..$ARGV[1]||10000" localhost 1000

From [http://web.archive.org/web/20021004112932/http://www.chrisangell.com/oneliners.html http://www.chrisangell.com/oneliners.html]

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'''Mandelbrot'''

perl -MPDL -MPDL::IO::Pic -e '$a=zeroes 300,300;$r=$a->xlinvals(-1.5,0.5);

$i=$a->ylinvals(-1,1);$t=$r;$u=$i;for(1..30){$q=$r**2-$i**2+$t;$h=2*$r*$i+$u;

$d=$r**2+$i**2;$a=lclip($a,$_*($d>2.0)*($a==0));

($r,$i)=map{$_->clip(-5,5)}($q,$h);}$a->wpic("mandel.gif");'

From [http://web.archive.org/web/20031025003129/http://www.tpj.com/documents/s=7228/tpjoneliners/one-liners01.html http://www.tpj.com/documents/s=7228/tpjoneliners/one-liners01.html]

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'''Rock, Scissors, Paper'''

perl -e "$c=(($r,$s,$p)=qw|rock scissors paper|)[(int rand 3)];

$|=0; until($y=~/^($r|$s|$p)$/){print \"$r, $s or $p? \";$y=<>;chop $y};

%r=($s,{$p,1,$r,0},$p,{$r,1,$s,0},$r,{$s,1,$p,0});

print \"You: $y\nCom: $c\nYou \".

((exists $r{$y}{$c}?($r{$y}{$c}?'Win': 'Lose'):'Draw').\"\n\")"

'''Bone::Easy <-> Chatbot::Eliza'''

perl -MChatbot::Eliza -MBone::Easy -e "$a=Chatbot::Eliza->new();

for(0..$ARGV[0]){$b=pickup(); $c=$a->transform($b);

print \"Bone: $b\nLiz: $c\n\"}print 'Liz: '.$a->final()->[0].\"\n\"" 10

From [http://web.archive.org/web/20020515231840/http://rollmop.org/oneliners/perl.html http://www.rollmop.org/oneliners/perl.html]

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== CGI ==

'''World's Shortest Wiki'''

<pre>

#!/usr/bin/perl

use CGI':all';path_info=~/\w+/;$_=`grep -l $& *`.h1($&).escapeHTML$t=param(t)

||`dd<$&`;open F,">$&";print F$t;s/htt\S+|([A-Z]\w+){2,}/a{href,$&},$&/eg;

print header,pre"$_<form>",submit,textarea t,$t,9,70

</pre>

From http://c2.com/cgi/wiki?SigWik

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== CLI ==

'''RSA in 5 lines of perl'''

#!/usr/bin/perl -s

do 'bigint.pl';($_,$n)=@ARGV;s/^.(..)*$/0$&/;($k=unpack('B*',pack('H*',$_)))=~

s/^0*//;$x=0;$z=$n=~s/./$x=&badd(&bmul($x,16),hex$&)/ge;while(read(STDIN,$_,$w

=((2*$d-1+$z)&~1)/2)){$r=1;$_=substr($_."\0"x$w,$c=0,$w);s/.|\n/$c=&badd(&bmul

($c,256),ord$&)/ge;$_=$k;s/./$r=&bmod(&bmul($r,$r),$x),$&?$r=&bmod(&bmul($r,$c),$x)

:0,""/ge;($r,$t)=&bdiv($r,256),$_=pack(C,$t).$_ while$w--+1-2*$d;print}

From http://www.cypherspace.org/adam/rsa/pureperl.html

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* [http://web.archive.org/web/20000119040744/http://elib.cs.berkeley.edu/~loretta/perl/nmanual/pod/perlfaq3/Why_don_t_perl_one_liners_work_o.html Why don't perl one-liners work on my DOS/Mac/VMS system?]

* [http://www.perlmonks.org/index.pl?node_id=324749 Uncommon* but Useful Perl Command Line Options for One-liners]