\documentclass{beamer}
%include lhs2TeX.fmt
\author{Piyush P Kurur\\
  Office no: 224\\
  Dept. of Comp. Sci. and Engg.\\
  IIT Kanpur}


\newcommand{\Token}[2][]{\node(#2#1)[token]{#2};}
\newcommand{\Symbol}[2][]{\node(#2#1)[symbol]{#2};}
\newcommand{\Point}[1]{\node(#1)[point]{#1};}

\usepackage{tikz}
\usetikzlibrary{positioning,shapes,chains,fit,shadows}
\usetikzlibrary{shapes.symbols}
\usetikzlibrary{matrix}
\usetikzlibrary{backgrounds}
\usetikzlibrary{shapes.geometric}
\usepackage{multicol}

\usepackage{algorithm2e}
\usepackage{pgfkeys}

\pgfkeys {%
  /tikz/oval/.style={%
    shape=ellipse,
    inner sep=1pt,
    drop shadow,
    draw = black
  },
  /tikz/redbox/.style={%
    shape=rectangle,%
    minimum size=1.5em,%
    top color = white, %
    bottom color=red!50!black!50,
    inner sep=0pt,
    draw=black
  },
  /tikz/null/.style={%
    shape=circle,
    minimum size=0.5em,
    draw=black,
  },
  /tikz/greybox/.style={ 
    shape=rectangle,%
    minimum width=7em,%
    minimum height=1.5em,
    fill=black!20,
    inner sep=0pt,
    draw=black
  },
  /tikz/blackbox/.style={ 
    shape=rectangle,%
    minimum width=7em,%
    minimum height=1.5em,
    fill=black,
    inner sep=0pt,
    draw=black
   },
  /tikz/whitebox/.style={
    shape=rectangle,
    minimum width=7em,
    minimum height=1.5em,
    draw=black
  },
  /tikz/bluebox/.style={
    shape=rectangle,
    minimum width=7em,
    minimum height=1.5em,
    fill=blue!40,
    draw=black
  },
  /tikz/whitetape/.style={
    shape=rectangle,
    minimum width=4em,
    minimum height=1.5em,
    draw=black
  },
  /tikz/bluearr/.style={
    ->,
    line width=0.25em, 
    draw=blue!40
  },
  /tikz/greenarr/.style={
    ->,
    line width=0.25em, 
    draw=green!40!black!60
  }
}
    
\newcommand{\arraythree}[4]{
  \begin{tikzpicture}[node distance=0]
    \pgfsetstrokeopacity{#4};
    \node[#1](a0#3){#2};
    \node[#1, right=of a0#3](a1#3){#2};
    \node[#1, right=of a1#3](a1#3){#2};
  \end{tikzpicture}
}

\newcommand{\arraytwo}[4]{
  \begin{tikzpicture}[node distance=0]
    \pgfsetstrokeopacity{#4};
    \node[#1](a0#3){#2};
    \node[#1,right=of a0#3]{#2};
  \end{tikzpicture}
}
  
\newcommand{\Array}[0]{
  \arraythree{box}{}{a}{1}
}

\newcommand{\AArray}[0]{%
  \arraythree{bbox}{\Array}{b}{0.5}}
\newcommand{\AAArray}[0]{%
  \arraytwo{bbbox}{\AArray}{c}{0.25}}

    
    
\newcommand{\T}[1]{\ensuremath{T\left(#1\right)}}  
\newcommand{\BigOh}[1]{\ensuremath{O\left(#1\right)}}
\title{Fundamentals of Computing: Lecture 39}
\date{November 13, 2009}
\begin{document}
\begin{frame}
  \maketitle
\end{frame}

\begin{frame}
  
  \frametitle{Conditionals statement}
  \pause
  \begin{multicols}{2}
  \begin{spec}
    if cmd
    then
        cmd
    fi
  \end{spec}
  \pause
  \newpage
  \begin{spec}
    if cmd
    then
       cmd
    else
       cmd
    fi
  \end{spec}
  \end{multicols}
\end{frame}
\begin{frame}
  \frametitle{Loop statements}
  \pause
  \begin{spec}
    while cmd
    do
       cmd
    done
  \end{spec}
  \pause
  \begin{spec}
    for i in *
    do
        echo The value of '$i' is "$i"
    done
  \end{spec}
 
\end{frame}

\end{document}
\begin{frame}
  \frametitle{Philosophy of shell programming} 

  There any many small but efficient programs.  Combine them.
  
  You need to know many of these common programs.
  
  \begin{itemize}
  \item |echo| prints its command line arguments
    \pause
  \item |less| shows int |stdin| in pages
    \begin{spec}
      $ cmd | less
      $ less foo bar biz
    \end{spec}
    \pause
  \item |grep pattern| shows only those lines of its stdin that
    matches the pattern.
  \end{itemize}
  \pause
  There are many more. 
  \pause
  To learn more, use command prompt always and read manpages.
\end{frame}