Just another Perl hacker, or JAPH, typically refers to a Perl

Perl

Perl is a high-level, general-purpose, interpreted, dynamic programming language. Perl was originally developed by Larry Wall in 1987 as a general-purpose Unix scripting language to make report processing easier. Since then, it has undergone many changes and revisions and become widely popular...

 program which prints "Just another Perl hacker," (the comma is canonical

Canonical

Canonical is an adjective derived from canon. Canon comes from the greek word κανών kanon, "rule" or "measuring stick" , and is used in various meanings....

 but is occasionally omitted). Short JAPH programs are often used as signatures

Signature block

A signature block is a block of text automatically appended at the bottom of an e-mail message, Usenet article, or forum post. This has the effect of "signing off" the message and in a reply message of indicating that no more response follows...

 in online forums

Internet forum

An Internet forum, or message board, is an online discussion site where people can hold conversations in the form of posted messages. They differ from chat rooms in that messages are at least temporarily archived...

, or as T-shirt

T-shirt

A T-shirt is a style of shirt. A T-shirt is buttonless and collarless, with short sleeves and frequently a round neck line....

 designs. The phrase or acronym is also occasionally used (without code) for a signature.

JAPH programs are classically done using extremely obfuscated

Obfuscated code

Obfuscated code is source or machine code that has been made difficult to understand for humans. Programmers may deliberately obfuscate code to conceal its purpose or its logic to prevent tampering, deter reverse engineering, or as a puzzle or recreational challenge for someone reading the source...

 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

Randal L. Schwartz

Randal L. Schwartz , also known as merlyn, is an American author, system administrator and programming consultant.-Career:...

, in his postings to the newsgroup

Newsgroup

A usenet newsgroup is a repository usually within the Usenet system, for messages posted from many users in different locations. The term may be confusing to some, because it is usually a discussion group. Newsgroups are technically distinct from, but functionally similar to, discussion forums on...

 comp.lang.perl. (In fact, many of the JAPHs below are his.)

Examples

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

String literal

A string literal is the representation of a string value within the source code of a computer program. There are numerous alternate notations for specifying string literals, and the exact notation depends on the individual programming language in question...

:


$_="krJhruaesrltre c a cnP,ohet";$_.=$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:

@P=split//,".URRUU\c8R";@d=split//,"\nrekcah xinU / lreP rehtona tsuJ";sub p{
@p{"r$p","u$p"}=(P,P);pipe"r$p","u$p";++$p;($q*=2)+=$f=!fork;map{$P=$P[$f^ord
($p{$_})&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

Keyword (computer programming)

In computer programming, a keyword is a word or identifier that has a particular meaning to the programming language. The meaning of keywords — and, indeed, the meaning of the notion of keyword — differs widely from language to language....

 (no literals or punctuation

Punctuation

Punctuation marks are symbols that indicate the structure and organization of written language, as well as intonation and pauses to be observed when reading aloud.In written English, punctuation is vital to disambiguate the meaning of sentences...

):


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

Punctuation

Punctuation marks are symbols that indicate the structure and organization of written language, as well as intonation and pauses to be observed when reading aloud.In written English, punctuation is vital to disambiguate the meaning of sentences...

, no alphanumeric

Alphanumeric

Alphanumeric is a combination of alphabetic and numeric characters, and is used to describe the collection of Latin letters and Arabic digits or a text constructed from this collection. There are either 36 or 62 alphanumeric characters. The alphanumeric character set consists of the numbers 0 to...

 characters (written by Eric Roode; only works on Unix

Unix

Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...

 and Unix-like

Unix-like

A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....

 systems):


`$=`;$_=\%!;($_)=/(.)/;$++$|;($.,$/,$,,$\,$",$;,$^,$#,$~,$*,$:,@%)=(
$!=~/(.)(.).(.)(.)(.)(.)..(.)(.)(.)..(.)......(.)/,$"),$=++;$.++;$.++;
$_++;$_++;($_,$\,$,)=($~.$"."$;$/$%[$?]$_$\$,$:$%[$?]",$"&$~,$#,);$,++
$,++;$^|=$";`$_$\$,$/$:$;$~$*$%[$?]$.$~$*${#}$%[$?]$;$\$"$^$~$*.>&$=`


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

=~('(?{'.('-)@.)@_*([]@!@/)(@)@-@),@(@@+@)'
^'][)@]`}`]`@.@]@%[`}%[@`@!#@%[').',"})')


ASCII art (to make this one work, be sure to set the console size to at least 119x48):

#
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,$o
,$h,$c,$k,$p,$e,$r,$l,$C)=split/}/,'Tw*JSK8IAg*PJ[*J@wR}*JR]*QJ[*J'.
'BA*JQK8I*JC}KUz]BAIJT]*QJ[R?-R[e]\RI'.'}Tn*JQ]wRAI*JDnR8QAU}wT8KT'.
']n*JEI*EJR*QJ]*JR*DJ@IQ[}*JSe*JD[n]*JPe*'.'JBI/KI}T8@?PcdnfgVCBRcP'.
'?ABKV]]}*JWe*JD[n]*JPe*JC?8B*JE};Vq*OJQ/IP['.'wQ}*JWeOe{n*EERk8;'.
'J*JC}/U*OJd[OI@*BJ*JXn*J>w]U}CWq*OJc8KJ?O[e]U/T*QJP?}*JSe*JCnTe'.
'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[PIQIOUKU\k*JE+J+J5R5AI*EJ00'. 'BCB*'.
'DMKKJIR[Q+*EJ0*EK';sub h{$\ = qw(% & @ x)[int rand
4];map{printf "\e[$b;%dm",int(rand 6)+101-60* ($w
||0);system( "cls")if$w ;($A,$S)= ($_[1], $
_[0]);($M, @,)= split '}';for( $z=256
;$z>0; $z -=$S){$S*= $A;p @,} sleep$_
[2];while ($_[3]&&($ z+=$ S) <=256){
p@,}}("". "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 @@@@@@@
#@@@@@@@@@@@

External links

• Cultured Perl: The Elegance of JAPH
• Cpan.org, a collection of JAPHs at CPAN
  CPAN
  CPAN, the Comprehensive Perl Archive Network, is an archive of nearly 100,000 modules of software written in Perl, as well as documentation for it. It has a presence on the World Wide Web at and is mirrored worldwide at more than 200 locations...
  
  .