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Just another Perl hacker

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Just another Perl hacker

Just another Perl hacker, or JAPH, typically refers to a Perl program which prints "Just another Perl hacker," (the comma is canonical but is occasionally omitted). Short JAPH programs are often used as signatures in online forums, or as T-shirt designs. The phrase or acronym is also occasionally used (without code) for a signature.

JAPH programs are classically done using extremely obfuscated methods, in the spirit of the Obfuscated C Contest. More recently, as the phenomenon has become so well known, the phrase is sometimes used in ordinary examples (without obfuscation).

The idea of using tiny Perl programs which print a signature as a signature was originated by Randal L. Schwartz, in his postings to the newsgroup comp.lang.perl.[1] (In fact, many of the JAPHs below are his.)


JAPH program without obfuscation:

print "Just another Perl hacker,";

Embedding JAPH in opaque code:

$_='987;s/^(\d+)/$1-1/e;$1?eval:print"Just another Perl hacker,"';eval;

Decoding JAPH from a transposed string literal:

$_="krJhruaesrltre c a cnP,ohet";$_.=$1,print$2while s/(..)(.)//;

Printing out JAPH as separate processes:

for $i (0..4) { if (!fork) {
      $i == 0 or not { $SIG{INT} = sub { print "J" } } or
      $i == 1 or not { $SIG{INT} = sub { print "A" } } or
      $i == 2 or not { $SIG{INT} = sub { print "P" } } or
      $i == 3 or not { $SIG{INT} = sub { print "H" } } ;
      sleep $i; last; } } kill INT => $$;

Appearing as if it does something completely unrelated to printing JAPH:

$_ = "wftedskaebjgdpjgidbsmnjgc";
tr/a-z/oh, turtleneck Phrase Jar!/; print;

Forking processes to print out one letter each in the correct order:[2]

@P=split//,".URRUU\c8R";@d=split//,"\nrekcah xinU / lreP rehtona tsuJ";sub p{
($p{$_})&6];$p{$_}=/ ^$P/ix?$P:close$_}keys%p}p;p;p;p;p;map{$p{$_}=~/^[P.]/&&
close$_}%p;wait until$?;map{/^r/&&<$_>}%p;$_=$d[$q];sleep rand(2)if/\S/;print

Using only Perl keywords (no literals or punctuation):[3]

not exp log srand xor s qq qx xor
s x x length uc ord and print chr
ord for qw q join use sub tied qx
xor eval xor print qq q q xor int
eval lc q m cos and print chr ord
for qw y abs ne open tied hex exp
ref y m xor scalar srand print qq
q q xor int eval lc qq y sqrt cos
and print chr ord for qw x printf
each return local x y or print qq
s s and eval q s undef or oct xor
time xor ref print chr int ord lc
foreach qw y hex alarm chdir kill
exec return y s gt sin sort split

Using only punctuation, no alphanumeric characters (written by Eric Roode; only works on Unix and Unix-like systems):


A much shorter one, using only punctuation, based on the EyeDrops module:


ASCII art (to make this one work, be sure to set the console size to at least 119×48):[4]

                                                   sub j(\$){($
                     P,$V)=                      @_;while($$P=~s:^
                 ([()])::x){                    $V+=('('eq$1)?-32:31
           }$V+=ord(  substr(                 $$P,0,1,""))-74} sub a{
          my($I,$K,$  J,$L)=@_               ;$I=int($I*$M/$Z);$K=int(
         $K*$M/$Z);$J=int($J*$M             /$Z);$L=int($L*$M/$Z); $G=$
         J-$I;$F=$L-$K;$E=(abs($          G)>=abs($F))?$G:$F;($E<0) and($
          I,$K)=($J,$L);$E||=.01       ;for($i=0;$i<=abs$E;$i++ ){ $D->{$K
                  +int($i*$F/$E)      }->{$I+int($i*$G/$E)}=1}}sub p{$D={};$
                 Z=$z||.01;map{    $H=$_;$I=$N=j$H;$K=$O=j$H;while($H){$q=ord
                substr($H,0,1,"" );if(42==$q){$J=j$H;$L=j$H}else{$q-=43;$L =$q
              %9;$J=($q-$L)/9;$L=$q-9*$J-4;$J-=4}$J+=$I;$L+=$K;a($I,$K,$J,$ L);
              ($I,$K)=($J,$L)}a($I,$K,$N,$O)}@_;my$T;map{$y=$_;map{ $T.=$D->{$y}
              ->{$_}?$\:' '}(-59..59);$T.="\n"}(-23..23);print"\e[H$T"}$w= eval{
              require Win32::Console::ANSI};$b=$w?'1;7;':"";($j,$u,$s,$t,$a,$n,$o
                   'QIAKJR}*JV]wRAI*J?}T]*RJcJI[\]3;U]Uq*PM[wV]W]WCT*DM*SJ'.  'ZP[Z'.
                      'PZa[\]UKVgogK9K*QJ[\]n[RI@*EH@IddR[Q[]T]T]T3o[dk*JE'.  '[Z\U'.
                        '{T]*JPKTKK]*OJ[QIO[PIQIO("".   "32}7D$j"     ."}AG".       "$u}OG"
                                ."$s}WG"    ."$t",""      ."24}("        ."IJ$a"
                                ."}1G$n"    ."}CO$o"     ."}GG$t"        ."}QC"
                                 ."$h}"      ."^G$e"    ."})IG"          ."$r",
                                 "32}?"       ."H$p}FG$e}QG$r".          "}ZC"
                                 ."$l",          "28}(LC" .""            ."".
                                 "$h}:"           ."J$a}EG".             "$c"
                                 ."}M"             ."C$k}ZG".            "$e"
                                 ."}"             ."dG$r","18"          ."}("
                                ."D;"            ."$C"  )}{h(16         ,1,1,0
                               );h(8,          .98,0,0   );h(16         ,1,1,1)
                               ;h(8.0         ,0.98,0,     1);         redo}###
                             #written                                 060204 by
                           #liverpole                                  @@@@@@@

See also


This article is based on material taken from the Free On-line Dictionary of Computing prior to 1 November 2008 and incorporated under the "relicensing" terms of the GFDL, version 1.3 or later.

  1. ^ Randal L. Schwartz in Usenet message M1HFPVH2JQ.FSF@HALFDOME.HOLDIT.COM explaining the origin of JAPH. Available through
  2. ^
  3. ^ Originally posted at by user blokhead
  4. ^ Originally posted at by user liverpole.

Further reading

  • Simon Cozens (2005). Advanced Perl Programming. O'Reilly. pp. 261–263.  

External links

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