Perl cheat sheet On-the-go

[Aragorn]

Category:

Miscellaneous

Description:

Juerd Waalboer's Perl 5 Cheat Sheet as an iPod Note.

<a name="top">Perl 5 Cheat Sheet</a>
by Arjen Laarhoven, based on Juerd Waalboer's cheat sheet

<a name="conttoc"><a href="#cont">Contexts</a></a>
<a name="sigtoc"><a href="#sig">Sigils</a></a>
<a name="arrtoc"><a href="#arr">Arrays</a></a>
<a name="hashtoc"><a href="#hash">Hashes</a></a>
<a name="scaltoc"><a href="#scal">Scalar values</a></a>
<a name="reftoc"><a href="#ref">References</a></a>
<a name="prectoc"><a href="#prec">Operator precedence</a></a>
<a name="numstrtoc"><a href="#numstr">Numbers/Strings</a></a>
<a name="remetatoc"><a href="#remeta">Regex metacharacters</a></a>
<a name="remodtoc"><a href="#remod">Regex modifiers</a></a>
<a name="rechartoc"><a href="#rechar">Regex character classes</a></a>
<a name="funcrettoc"><a href="#funcret">Function return lists</a></a>
<a name="specvartoc"><a href="#specvars">Special variables</a></a>
<a name="dotoc"><a href="#do">Do</a></a>
<a name="donttoc"><a href="#dont">Don't</a></a>
<a name="linkstoc"><a href="#links">Links</a></a>

<a name="cont"><a href="#conttoc">CONTEXTS</a></a>
  void scalar list

<a name="sig"><a href="#sigtoc">SIGILS</a></a>
  $scalar @array %hash
  &sub *glob

<a name="arr"><a href="#arrtoc">ARRAYS</a></a>
  @array @array[0, 2]
  $array[0]

<a name="hash"><a href="#hashtoc">HASHES</a></a>
  %hash $hash{'a'}
  @hash{'a','b'}

<a name="scal"><a href="#scaltoc">SCALAR VALUES</a></a>
  number string reference
  glob undef

<a name="ref"><a href="#reftoc">REFERENCES</a></a>
  \ reference
  $@%&* dereference
  [] anon arrayref
  {} anon hashref
  \() list of refs

  $$foo[1] => $foo->[1]
  $$foo{bar} => $foo->{bar}
  ${$$foo[1]}[2]
    => $foo->[1]->[2]
  ${$$foo[1]}[2]
    => $foo->[1][2]

<a name="prec"><a href="#prectoc">Operator Precedence</a></a>
  ->
  ++ --
  **
  ! ~ / u+ u-
  =~ !~
  * / % x
  + - .
  << >>
  named uops
  < > <= >= lt gt le ge
  == != <=> eq ne cmp
  &
  | ^
  &&
  ||
  .. ...
  ?:
  = += -= *= etc.
  list ops
  not
  and
  or
  xor

<a name="numstr"><a href="#numstrtoc">NUMBERS/STRINGS</a></a>
  NUM           STR
  =                 =
  +                 .
  == !=          eq ne
  < > <= >=    lt gt le ge
  <=>             cmp

<a name="remeta"><a href="#remetatoc">REGEX METACHARACTERS</a></a>
  ^ string begin
  $ string end
  + one or more
  * zero or more
  ? zero or one
  {3,7} repeat in range
  () capture
  (?:) no capture
  [] character class
  | alternation
  \b word boundary
  \z string end

<a name="remod"><a href="#remodtoc">REGEX MODIFIERS</a></a>
  /i case insens.
  /m line based ^$
  /s . includes \n
  /x ignore whitespace
  /g global

<a name="rechar"><a href="#rechartoc">REGEX CHARCLASSES</a></a>
  .     == [^\n]
  \s   == [\x20\f\t\r\n]
  \w == [A-Za-z0-9_]
  \d  == [0-9]
  \S, \W and \D negate

<a name="funcret"><a href="#funcrettoc">FUNCTION RETURN LISTS</a></a>
  stat         localtime
  0 dev      0 second
  1 ino       1 minute
  2 mode   2 hour
  3 nlink     3 day
  4 uid        4 mon-1
  5 gid        5 yr-1900
  6 rdev     6 wday
  7 size      7 yrday
  8 atime   8 is_dst
  9 mtime
 10 ctime
 11 blksz
 12 blcks

  caller
  0 package     5 wantarray  
  1 filename    6 evaltext
  2 line             7 is_require
  3 subroutine 8 hints
  4 hashargs   9 bitmask 
  0..9 only with EXPR

<a name="specvars"><a href="#specvarstoc">SPECIAL VARIABLES</a></a>
  $_ default variable
  $0 program name
  $/ input separator
  $\ output separator
  $| autoflush
  $! sys/libcall error
  $@ eval error
  $$ process ID
  $. line number
  @ARGV command line args
  @INC include paths
  @_ subroutine args
  %ENV environment

<a name="do"><a href="#dotoc">DO</a></a>
  use strict;
  use warnings;
  my $var;
  open() or die $!;
  use Modules;

<a name="dont"><a href="#donttoc">DON'T</a></a>
  "$foo"
  $$variable_name
  `$userinput`
  /$userinput/ 

<a name="links"><a href="#linkstoc">LINKS</a></a>
  perl.plover.com
  search.cpan.org
  cpan.org
  pm.org
  tpj.com
  perldoc.com
  perl.com
  perlmonks.org
  use.perl.org
  perl.apache.org
  parrotcode.org