\documentclass[10pt,a4paper]{article}

% Packages
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\usepackage{multicol}           % Allows multicols in tables
\usepackage{tabularx}           % Intelligent column widths
\usepackage{tabulary}           % Used in header and footer
\usepackage{hhline}             % Border under tables
\usepackage{graphicx}           % For images
\usepackage{xcolor}             % For hex colours
%\usepackage[utf8x]{inputenc}    % For unicode character support
\usepackage[T1]{fontenc}        % Without this we get weird character replacements
\usepackage{colortbl}           % For coloured tables
\usepackage{setspace}           % For line height
\usepackage{lastpage}           % Needed for total page number
\usepackage{seqsplit}           % Splits long words.
%\usepackage{opensans}          % Can't make this work so far. Shame. Would be lovely.
\usepackage[normalem]{ulem}     % For underlining links
% Most of the following are not required for the majority
% of cheat sheets but are needed for some symbol support.
\usepackage{amsmath}            % Symbols
\usepackage{MnSymbol}           % Symbols
\usepackage{wasysym}            % Symbols
%\usepackage[english,german,french,spanish,italian]{babel}              % Languages

% Document Info
\author{respi (respi)}
\pdfinfo{
  /Title (special-vars-quick-reference.pdf)
  /Creator (Cheatography)
  /Author (respi (respi))
  /Subject (Special Vars Quick Reference Cheat Sheet)
}

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% This two commands together give roughly
% the right line height in the tables
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% Commands
\newcommand{\SetRowColor}[1]{\noalign{\gdef\RowColorName{#1}}\rowcolor{\RowColorName}} % Shortcut for row colour
\newcommand{\mymulticolumn}[3]{\multicolumn{#1}{>{\columncolor{\RowColorName}}#2}{#3}} % For coloured multi-cols
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% Header and Footer
\pagestyle{fancy}
\fancyhead{} % Set header to blank
\fancyfoot{} % Set footer to blank
\fancyhead[L]{
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{C}
    \SetRowColor{DarkBackground}
    \vspace{-7pt}
    {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent
        \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}}
    }
\end{tabulary}
\columnbreak
\begin{tabulary}{11cm}{L}
    \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{Special Vars Quick Reference Cheat Sheet}}}} \\
    \normalsize{by \textcolor{DarkBackground}{respi (respi)} via \textcolor{DarkBackground}{\uline{cheatography.com/19521/cs/2525/}}}
\end{tabulary}
\end{multicols}}

\fancyfoot[L]{ \footnotesize
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{LL}
  \SetRowColor{FootBackground}
  \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}}  \\
  \vspace{-2pt}respi (respi) \\
  \uline{cheatography.com/respi} \\
  \end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}}  \\
   \vspace{-2pt}Published 8th September, 2014.\\
   Updated 12th May, 2016.\\
   Page {\thepage} of \pageref{LastPage}.
\end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Sponsor}}  \\
  \SetRowColor{white}
  \vspace{-5pt}
  %\includegraphics[width=48px,height=48px]{dave.jpeg}
  Measure your website readability!\\
  www.readability-score.com
\end{tabulary}
\end{multicols}}




\begin{document}
\raggedright
\raggedcolumns

% Set font size to small. Switch to any value
% from this page to resize cheat sheet text:
% www.emerson.emory.edu/services/latex/latex_169.html
\footnotesize % Small font.

\begin{multicols*}{3}

\begin{tabularx}{5.377cm}{p{0.64701 cm} x{4.32999 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Standard}}  \tn
% Row 0
\SetRowColor{LightBackground}
\$\_ & The default or implicit variable \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
@\_ & Subroutine parameters \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
\$a \$b & Sort comparison routine variables \tn 
% Row Count 3 (+ 1)
% Row 3
\SetRowColor{white}
@ARGV & The command-line args \tn 
% Row Count 4 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{p{0.4977 cm} x{4.4793 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{ID's and Process Information}}  \tn
% Row 0
\SetRowColor{LightBackground}
\$\$ & Process ID \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\$\textless{} & Real user id of process \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
\$\textgreater{} & Effective user id of process \tn 
% Row Count 3 (+ 1)
% Row 3
\SetRowColor{white}
\$( & Real group id of process \tn 
% Row Count 4 (+ 1)
% Row 4
\SetRowColor{LightBackground}
\$) & Effective group id of process \tn 
% Row Count 5 (+ 1)
% Row 5
\SetRowColor{white}
\$0 & Program name \tn 
% Row Count 6 (+ 1)
% Row 6
\SetRowColor{LightBackground}
\$\textasciicircum{}O & Operating System name \tn 
% Row Count 7 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{x{1.89126 cm} x{3.08574 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Encoding}}  \tn
% Row 0
\SetRowColor{LightBackground}
\{\{nobreak\}\}\$\{\textasciicircum{}ENCODING\} & The object reference to the Encode object, used to convert the source code to Unicode \tn 
% Row Count 4 (+ 4)
% Row 1
\SetRowColor{white}
\$\{\textasciicircum{}OPEN\} & Internal use: \textbackslash{}0 separated Input / Output layer information \tn 
% Row Count 7 (+ 3)
% Row 2
\SetRowColor{LightBackground}
\$\{\textasciicircum{}UNICODE\} & Read-only Unicode settings \tn 
% Row Count 9 (+ 2)
% Row 3
\SetRowColor{white}
\{\{nobreak\}\}\$\{\textasciicircum{}UTF8CACHE\} & State of the internal UTF-8 offset caching code \tn 
% Row Count 11 (+ 2)
% Row 4
\SetRowColor{LightBackground}
\{\{nobreak\}\}\$\{\textasciicircum{}UTF8LOCALE\} & Indicates whether UTF8 locale was detected at startup \tn 
% Row Count 14 (+ 3)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{p{0.4977 cm} x{4.4793 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Miscellaneous}}  \tn
% Row 0
\SetRowColor{LightBackground}
@F & Autosplit (-a mode) recipient \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
@INC & List of library paths \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
\%INC & Keys are filenames, values are paths to modules included via `use`, `require`, or `do` \tn 
% Row Count 5 (+ 3)
% Row 3
\SetRowColor{white}
\%ENV & Hash containing current environment variables \tn 
% Row Count 7 (+ 2)
% Row 4
\SetRowColor{LightBackground}
\%SIG & Signal handlers \tn 
% Row Count 8 (+ 1)
% Row 5
\SetRowColor{white}
\${[} & Array and substr first element (Deprecated!) \tn 
% Row Count 10 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{x{2.23965 cm} x{2.73735 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Status Reporting}}  \tn
% Row 0
\SetRowColor{LightBackground}
\$? & Child error. Status code of most recent system call or pipe \tn 
% Row Count 3 (+ 3)
% Row 1
\SetRowColor{white}
\$! & Operating System Error. (What just went 'bang'?) \tn 
% Row Count 6 (+ 3)
% Row 2
\SetRowColor{LightBackground}
\$\textasciicircum{}E & Extended Operating System Error (Extra error explanation) \tn 
% Row Count 9 (+ 3)
% Row 3
\SetRowColor{white}
\$@ & Eval error \tn 
% Row Count 10 (+ 1)
% Row 4
\SetRowColor{LightBackground}
\{\{nobreak\}\}\$\{\textasciicircum{}CHILD\_ERROR\_NATIVE\} & Native status returned by the last pipe close, backtick (`` ) command, successful call to wait() or waitpid(), or from the system() operator \tn 
% Row Count 17 (+ 7)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{p{0.4977 cm} x{4.4793 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{IO and Separators}}  \tn
% Row 0
\SetRowColor{LightBackground}
\$. & Current line number (or record number) of most recent filehandle \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
\$/ & Input record separator \tn 
% Row Count 3 (+ 1)
% Row 2
\SetRowColor{LightBackground}
\$| & Output autoflush. 1=autoflush, 0=default. Applies to currently selected handle \tn 
% Row Count 6 (+ 3)
% Row 3
\SetRowColor{white}
\$, & Output field separator (lists) \tn 
% Row Count 7 (+ 1)
% Row 4
\SetRowColor{LightBackground}
\$\textbackslash{} & Output record separator \tn 
% Row Count 8 (+ 1)
% Row 5
\SetRowColor{white}
\$" & Output list separator. (interpolated lists) \tn 
% Row Count 10 (+ 2)
% Row 6
\SetRowColor{LightBackground}
\$; & Subscript separator. (Use a real multidimensional array instead) \tn 
% Row Count 12 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{x{2.09034 cm} x{2.88666 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Regular Expressions}}  \tn
% Row 0
\SetRowColor{LightBackground}
\$\textless{}digit\textgreater{} & Regexp parenthetical capture holders \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
\$\& & Last successful match (degrades performance) \tn 
% Row Count 4 (+ 2)
% Row 2
\SetRowColor{LightBackground}
\{\{nobreak\}\}\$\{\textasciicircum{}MATCH\} & Similar to \$\& without performance penalty. Requires /p modifier \tn 
% Row Count 7 (+ 3)
% Row 3
\SetRowColor{white}
\$` & Prematch for last successful match string (degrades performance) \tn 
% Row Count 10 (+ 3)
% Row 4
\SetRowColor{LightBackground}
\{\{nobreak\}\}\$\{\textasciicircum{}PREMATCH\} & Similar to \$` without performance penalty. Requires /p modifier \tn 
% Row Count 13 (+ 3)
% Row 5
\SetRowColor{white}
\$' & Postmatch for last successful match string (degrades performance) \tn 
% Row Count 16 (+ 3)
% Row 6
\SetRowColor{LightBackground}
\{\{nobreak\}\}\$\{\textasciicircum{}POSTMATCH\} & Similar to \$' without performance penalty. Requires /p modifier \tn 
% Row Count 19 (+ 3)
% Row 7
\SetRowColor{white}
\$+ & Last paren match \tn 
% Row Count 20 (+ 1)
% Row 8
\SetRowColor{LightBackground}
\$\textasciicircum{}N & Last closed paren match (last submatch) \tn 
% Row Count 22 (+ 2)
% Row 9
\SetRowColor{white}
@+ & Offsets of ends of successful submatches in scope \tn 
% Row Count 25 (+ 3)
% Row 10
\SetRowColor{LightBackground}
@- & Offsets of starts of successful submatches in scope \tn 
% Row Count 28 (+ 3)
% Row 11
\SetRowColor{white}
\%+ & Like @+, but for named submatches \tn 
% Row Count 30 (+ 2)
\end{tabularx}
\par\addvspace{1.3em}

\vfill
\columnbreak
\begin{tabularx}{5.377cm}{x{2.09034 cm} x{2.88666 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Regular Expressions (cont)}}  \tn
% Row 12
\SetRowColor{LightBackground}
\%- & Like @-, but for named submatches \tn 
% Row Count 2 (+ 2)
% Row 13
\SetRowColor{white}
\$\textasciicircum{}R & Last regexp (?\{code\}) result \tn 
% Row Count 4 (+ 2)
% Row 14
\SetRowColor{LightBackground}
\{\{nobreak\}\}\$\{\textasciicircum{}RE\_DEBUG\_FLAGS\} & Current value of regexp debugging flags. See use re 'debug' \tn 
% Row Count 7 (+ 3)
% Row 15
\SetRowColor{white}
\{\{nobreak\}\}\$\{\textasciicircum{}RE\_TRIE\_MAXBUF\} & Control memory allocations for RE optimizations for large alternations \tn 
% Row Count 11 (+ 4)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{x{2.18988 cm} x{2.78712 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Perl Status Info}}  \tn
% Row 0
\SetRowColor{LightBackground}
\${]} & Old: Version and patch number of perl interpreter. Deprecated \tn 
% Row Count 3 (+ 3)
% Row 1
\SetRowColor{white}
\$\textasciicircum{}C & Current value of flag associated with -c switch \tn 
% Row Count 6 (+ 3)
% Row 2
\SetRowColor{LightBackground}
\$\textasciicircum{}D & Current value of debugging flags \tn 
% Row Count 8 (+ 2)
% Row 3
\SetRowColor{white}
\$\textasciicircum{}F & Maximum system file descriptor \tn 
% Row Count 10 (+ 2)
% Row 4
\SetRowColor{LightBackground}
\$\textasciicircum{}I & Value of the -i (inplace edit) switch \tn 
% Row Count 12 (+ 2)
% Row 5
\SetRowColor{white}
\$\textasciicircum{}M & Emergency Memory pool \tn 
% Row Count 13 (+ 1)
% Row 6
\SetRowColor{LightBackground}
\$\textasciicircum{}P & Internal variable for debugging support \tn 
% Row Count 15 (+ 2)
% Row 7
\SetRowColor{white}
\$\textasciicircum{}R & Last regexp (?\{code\}) result \tn 
% Row Count 17 (+ 2)
% Row 8
\SetRowColor{LightBackground}
\$\textasciicircum{}S & Exceptions being caught. (eval) \tn 
% Row Count 19 (+ 2)
% Row 9
\SetRowColor{white}
\$\textasciicircum{}T & Base time of program start \tn 
% Row Count 21 (+ 2)
% Row 10
\SetRowColor{LightBackground}
\$\textasciicircum{}V & Perl version \tn 
% Row Count 22 (+ 1)
% Row 11
\SetRowColor{white}
\$\textasciicircum{}W & Status of -w switch \tn 
% Row Count 23 (+ 1)
% Row 12
\SetRowColor{LightBackground}
\{\{nobreak\}\}\$\{\textasciicircum{}WARNING\_BITS\} & Current set of warning checks enabled by `use warnings;` \tn 
% Row Count 26 (+ 3)
% Row 13
\SetRowColor{white}
\$\textasciicircum{}X & Perl executable name \tn 
% Row Count 27 (+ 1)
% Row 14
\SetRowColor{LightBackground}
\{\{nobreak\}\}\$\{\textasciicircum{}GLOBAL\_PHASE\} & Current phase of the Perl interpreter \tn 
% Row Count 29 (+ 2)
% Row 15
\SetRowColor{white}
\$\textasciicircum{}H & Internal use only: Hook into Lexical Scoping \tn 
% Row Count 31 (+ 2)
\end{tabularx}
\par\addvspace{1.3em}

\vfill
\columnbreak
\begin{tabularx}{5.377cm}{x{2.18988 cm} x{2.78712 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Perl Status Info (cont)}}  \tn
% Row 16
\SetRowColor{LightBackground}
\%\textasciicircum{}H & Internaluse only: Useful to implement scoped pragmas \tn 
% Row Count 3 (+ 3)
% Row 17
\SetRowColor{white}
\$\{\textasciicircum{}TAINT\} & Taint mode read-only flag \tn 
% Row Count 5 (+ 2)
% Row 18
\SetRowColor{LightBackground}
\{\{nobreak\}\}\$\{\textasciicircum{}WIN32\_SLOPPY\_STAT\} & If true on Windows `stat()` won't try to open the file \tn 
% Row Count 8 (+ 3)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{p{0.74655 cm} x{4.23045 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Command Line Args}}  \tn
% Row 0
\SetRowColor{LightBackground}
ARGV & Filehandle iterates over files from command line (see also `\textless{}\textgreater{}`) \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
\$ARGV & Name of current file when reading \textless{}\textgreater{} \tn 
% Row Count 4 (+ 2)
% Row 2
\SetRowColor{LightBackground}
@ARGV & List of command line args \tn 
% Row Count 5 (+ 1)
% Row 3
\SetRowColor{white}
\seqsplit{ARGVOUT} & Output filehandle for -i switch \tn 
% Row Count 7 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}


% That's all folks
\end{multicols*}

\end{document}