Just another Perl hacker, or JAPH, typically refers to a Perl program that 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 that print a signature as a signature was originated by Randal L. Schwartz, in his postings to the newsgroup comp.lang.perl.[1] He wrote many of the JAPHs which are shown below.
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:
$_="krJhruaesrltre c a cnP,ohet";$_.=$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 => $$; Appearing as if it does something completely unrelated to printing JAPH:
$_ = "wftedskaebjgdpjgidbsmnjgc"; tr/a-z/oh, turtleneck Phrase Jar!/; print; Forking processes to print out one letter each in the correct order:[2]
@P=split//,".URRUU\c8R";@d=split//,"\nrekcah xinU / lreP rehtona tsuJ";sub p{ @p{"r$p","u$p"}=(P,P);pipe"r$p","u$p";++$p;($q*=2)+=$f=!fork;map{$P=$P[$f^ord ($p{$_})&6];$p{$_}=/ ^$P/ix?$P:close$_}keys%p}p;p;p;p;p;map{$p{$_}=~/^[P.]/&& close$_}%p;wait until$?;map{/^r/&&<$_>}%p;$_=$d[$q];sleep rand(2)if/\S/;print Using only Perl keywords (no punctuation):[3]
not exp log srand xor s qq qx xor s x x length uc ord and print chr ord for qw q join use sub tied qx xor eval xor print qq q q xor int eval lc q m cos and print chr ord for qw y abs ne open tied hex exp ref y m xor scalar srand print qq q q xor int eval lc qq y sqrt cos and print chr ord for qw x printf each return local x y or print qq s s and eval q s undef or oct xor time xor ref print chr int ord lc foreach qw y hex alarm chdir kill exec return y s gt sin sort split Using only punctuation, no alphanumeric characters. This breaks after Perl 5.30.0, as using $# and $* create fatal errors. This JAPH was written by Eric Roode and only works on Unix and Unix-like systems:
`$=`;$_=\%!;($_)=/(.)/;$==++$|;($.,$/,$,,$\,$",$;,$^,$#,$~,$*,$:,@%)=( $!=~/(.)(.).(.)(.)(.)(.)..(.)(.)(.)..(.)......(.)/,$"),$=++;$.++;$.++; $_++;$_++;($_,$\,$,)=($~.$"."$;$/$%[$?]$_$\$,$:$%[$?]",$"&$~,$#,);$,++ ;$,++;$^|=$";`$_$\$,$/$:$;$~$*$%[$?]$.$~$*${#}$%[$?]$;$\$"$^$~$*.>&$=` A much shorter one, using only punctuation, based on the EyeDrops module:
''=~('(?{'.('-)@.)@_*([]@!@/)(@)@-@),@(@@+@)' ^'][)@]`}`]`@.@]@%[`}%[@`@!#@%[').',"})') ASCII art (to make this dromedary-shaped code work, the console size needs to be set to at least 119×48):[4]
# sub j(\$){($ P,$V)= @_;while($$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,$o ,$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[PIQIO[[gUKU\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 @@@@@@@ #@@@@@@@@@@@ See also
- "Hello, World!" program
- Java Pet Store
- Obfuscated Perl Contest
- Perl golf
References
- ^ Randal L. Schwartz in Usenet message M1HFPVH2JQ.FSF@HALFDOME.HOLDIT.COM explaining the origin of JAPH. Available through Google.com
- ^ Plover.com
- ^ Originally posted at perlmonks.org by user blokhead
- ^ Originally posted at perlmonks.org by user liverpole.
Further reading
- Simon Cozens (2005). Advanced Perl Programming. O'Reilly. pp. 261–263. ISBN 9780596004569.
External links
- Cultured Perl: The Elegance of JAPH
- Cpan.org, a collection of JAPHs at CPAN.
- How does this famous JAPh work? and Fun With Reserved Keywords at Stack Overflow explain how blokhead's code works.