.\" Automatically generated by Pod::Man 4.14 (Pod::Simple 3.40) .\" .\" Standard preamble: .\" ======================================================================== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. \*(C+ will .\" give a nicer C++. Capital omega is used to do unbreakable dashes and .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff, .\" nothing in troff, for use with C<>. .tr \(*W- .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} .el\{\ . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . ds C` . ds C' 'br\} .\" .\" Escape single quotes in literal strings from groff's Unicode transform. .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" .\" If the F register is >0, we'll generate index entries on stderr for .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index .\" entries marked with X<> in POD. Of course, you'll have to process the .\" output yourself in some meaningful fashion. .\" .\" Avoid warning from groff about undefined register 'F'. .de IX .. .nr rF 0 .if \n(.g .if rF .nr rF 1 .if (\n(rF:(\n(.g==0)) \{\ . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF .\" ======================================================================== .\" .IX Title "PERLCHEAT 1" .TH PERLCHEAT 1 "2021-09-24" "perl v5.32.1" "Perl Programmers Reference Guide" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "NAME" perlcheat \- Perl 5 Cheat Sheet .SH "DESCRIPTION" .IX Header "DESCRIPTION" This 'cheat sheet' is a handy reference, meant for beginning Perl programmers. Not everything is mentioned, but 195 features may already be overwhelming. .SS "The sheet" .IX Subsection "The sheet" .Vb 10 \& CONTEXTS SIGILS ref ARRAYS HASHES \& void $scalar SCALAR @array %hash \& scalar @array ARRAY @array[0, 2] @hash{\*(Aqa\*(Aq, \*(Aqb\*(Aq} \& list %hash HASH $array[0] $hash{\*(Aqa\*(Aq} \& &sub CODE \& *glob GLOB SCALAR VALUES \& FORMAT number, string, ref, glob, undef \& REFERENCES \& \e reference $$foo[1] aka $foo\->[1] \& $@%&* dereference $$foo{bar} aka $foo\->{bar} \& [] anon. arrayref ${$$foo[1]}[2] aka $foo\->[1]\->[2] \& {} anon. hashref ${$$foo[1]}[2] aka $foo\->[1][2] \& \e() list of refs \& SYNTAX \& OPERATOR PRECEDENCE foreach (LIST) { } for (a;b;c) { } \& \-> while (e) { } until (e) { } \& ++ \-\- if (e) { } elsif (e) { } else { } \& ** unless (e) { } elsif (e) { } else { } \& ! ~ \e u+ u\- given (e) { when (e) {} default {} } \& =~ !~ \& * / % x NUMBERS vs STRINGS FALSE vs TRUE \& + \- . = = undef, "", 0, "0" \& << >> + . anything else \& named uops == != eq ne \& < > <= >= lt gt le ge < > <= >= lt gt le ge \& == != <=> eq ne cmp ~~ <=> cmp \& & \& | ^ REGEX MODIFIERS REGEX METACHARS \& && /i case insensitive ^ string begin \& || // /m line based ^$ $ str end (bfr \en) \& .. ... /s . includes \en + one or more \& ?: /x /xx ign. wh.space * zero or more \& = += last goto /p preserve ? zero or one \& , => /a ASCII /aa safe {3,7} repeat in range \& list ops /l locale /d dual | alternation \& not /u Unicode [] character class \& and /e evaluate /ee rpts \eb boundary \& or xor /g global \ez string end \& /o compile pat once () capture \& DEBUG (?:p) no capture \& \-MO=Deparse REGEX CHARCLASSES (?#t) comment \& \-MO=Terse . [^\en] (?=p) ZW pos ahead \& \-D## \es whitespace (?!p) ZW neg ahead \& \-d:Trace \ew word chars (?<=p) ZW pos behind \eK \& \ed digits (?p) no backtrack \& perl \-V:ivsize \eh horiz.wh.space (?|p|p)branch reset \& \eR linebreak (?p)named capture \& \eS \eW \eD \eH negate \eg{n} ref to named cap \& \eK keep left part \& FUNCTION RETURN LISTS \& stat localtime caller SPECIAL VARIABLES \& 0 dev 0 second 0 package $_ default variable \& 1 ino 1 minute 1 filename $0 program name \& 2 mode 2 hour 2 line $/ input separator \& 3 nlink 3 day 3 subroutine $\e output separator \& 4 uid 4 month\-1 4 hasargs $| autoflush \& 5 gid 5 year\-1900 5 wantarray $! sys/libcall error \& 6 rdev 6 weekday 6 evaltext $@ eval error \& 7 size 7 yearday 7 is_require $$ process ID \& 8 atime 8 is_dst 8 hints $. line number \& 9 mtime 9 bitmask @ARGV command line args \& 10 ctime 10 hinthash @INC include paths \& 11 blksz 3..10 only @_ subroutine args \& 12 blcks with EXPR %ENV environment .Ve .SH "ACKNOWLEDGEMENTS" .IX Header "ACKNOWLEDGEMENTS" The first version of this document appeared on Perl Monks, where several people had useful suggestions. Thank you, Perl Monks. .PP A special thanks to Damian Conway, who didn't only suggest important changes, but also took the time to count the number of listed features and make a Raku version to show that Perl will stay Perl. .SH "AUTHOR" .IX Header "AUTHOR" Juerd Waalboer <#####@juerd.nl>, with the help of many Perl Monks. .SH "SEE ALSO" .IX Header "SEE ALSO" .IP "\(bu" 4 \- the original \s-1PM\s0 post .IP "\(bu" 4 \- Damian Conway's Raku version .IP "\(bu" 4 \- home of the Perl Cheat Sheet