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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Using Linux Tools
%
% Author: FOSSEE
% Copyright (c) 2009, FOSSEE, IIT Bombay
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\documentclass[12pt,compress]{beamer}
\mode<presentation>
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\useoutertheme{infolines}
\setbeamercovered{transparent}
}
\usepackage[english]{babel}
\usepackage[latin1]{inputenc}
%\usepackage{times}
\usepackage[T1]{fontenc}
% Taken from Fernando's slides.
\usepackage{ae,aecompl}
\usepackage{mathpazo,courier,euler}
\usepackage[scaled=.95]{helvet}
\definecolor{darkgreen}{rgb}{0,0.5,0}
\usepackage{listings}
\lstset{language=sh,
basicstyle=\ttfamily\bfseries,
commentstyle=\color{red}\itshape,
stringstyle=\color{darkgreen},
showstringspaces=false,
keywordstyle=\color{blue}\bfseries}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% DOCUMENT STARTS
\begin{document}
\begin{frame}
\begin{center}
\vspace{12pt}
\textcolor{blue}{\huge Using Linux Tools\\Part IV}
\end{center}
\vspace{18pt}
\begin{center}
\vspace{10pt}
\includegraphics[scale=0.95]{../images/fossee-logo.png}\\
\vspace{5pt}
\scriptsize Developed by FOSSEE Team, IIT-Bombay. \\
\scriptsize Funded by National Mission on Education through ICT\\
\scriptsize MHRD,Govt. of India\\
\includegraphics[scale=0.30]{../images/iitb-logo.png}\\
\end{center}
\end{frame}
\begin{frame}
\frametitle{Objectives}
\label{sec-2}
At the end of this tutorial, you will be able to,
\begin{itemize}
\item Understand what is Redirection and Piping.
\item Learn various features of the shell.
\end{itemize}
\end{frame}
\begin{frame}
\frametitle{Pre-requisite}
\label{sec-3}
Spoken tutorial on -
\begin{itemize}
\item Using Linux tools -- Part I
\item Using Linux tools -- Part II
\item Using Linux tools -- Part III
\end{itemize}
\end{frame}
\begin{frame}[fragile]
\frametitle{Redirection}
\begin{itemize}
\item The standard output (stdout) stream goes to the display
\item Not always, what we need
\item First solution, redirects output to a file
\item \texttt{>} states that output is redirected; It is
followed by location to redirect
\end{itemize}
\begin{lstlisting}
$ command > file1
\end{lstlisting} % $
\begin{itemize}
\item \texttt{>} creates a new file at specified location
\item \texttt{>>} appends to a file at specified location
\end{itemize}
\end{frame}
\begin{frame}[fragile]
\frametitle{Redirection \ldots}
\begin{itemize}
\item Similarly, the standard input (stdin) can be redirected
\end{itemize}
\begin{lstlisting}
$ command < file1
\end{lstlisting} % $
\begin{itemize}
\item input and the output redirection could be combined
\end{itemize}
\begin{lstlisting}
$ command < infile > outfile
\end{lstlisting} % $
\begin{itemize}
\item Standard error (stderr) is the third standard stream
\item All error messages come through this stream
\item \texttt{stderr} can also be redirected
\end{itemize}
\end{frame}
\begin{frame}[fragile]
\frametitle{Piping}
\begin{lstlisting}
$ cut -d " " -f 2- marks1.txt \
| paste -d " " students.txt -
\end{lstlisting} % $
\begin{itemize}
\item \texttt{-} instead of FILE asks \texttt{paste} to read from
\texttt{stdin}
\item \texttt{cut} command is a normal command
\item the \texttt{|} seems to be joining the two commands
\item Redirects output of first command to \texttt{stdin}, which
becomes input to the second command
\item This is called piping; \texttt{|} is called a pipe
\end{itemize}
\end{frame}
\begin{frame}[fragile]
\frametitle{Piping \ldots}
\begin{itemize}
\item Roughly same as -- 2 redirects and a temporary file
\end{itemize}
\begin{lstlisting}
$ command1 > tempfile
$ command2 < tempfile
$ rm tempfile
\end{lstlisting} % $
\begin{itemize}
\item Any number of commands can be piped together
\end{itemize}
\end{frame}
\subsection{Features of the Shell}
\begin{frame}[fragile]
\frametitle{Tab-completion}
\begin{itemize}
\item Bash provides tab completion for the following.
\begin{enumerate}
\item File Names
\item Directory Names
\item Executable Names
\item User Names (when they are prefixed with a \~{})
\item Host Names (when they are prefixed with a @)
\item Variable Names (when they are prefixed with a \$)
\end{enumerate}
\end{itemize}
\end{frame}
\begin{frame}[fragile]
\frametitle{Shell Meta Characters}
\begin{itemize}
\item ``meta characters'' are special command directives
\item File-names shouldn't have meta-characters
\item The following are the shell meta characters --
\begin{itemize}
\item \verb+/<>!$%^&*|{}[]"'`~;+
\end{itemize}
\end{itemize}
\end{frame}
\begin{frame}
\frametitle{Summary}
\label{sec-8}
In this tutorial, we have learnt to,
\begin{itemize}
\item Use the ``cut'' and ``paste'' commands in redirection.
\item Use the pipe ( | ) character.
\item Implement features of shell like tab-completion and history.
\end{itemize}
\end{frame}
\begin{frame}[fragile]
\frametitle{Evaluation}
\label{sec-9}
\begin{enumerate}
\item Bash does not provide tab completion for Host Names. \\
True or False?
\vspace{12pt}
\item In a file /home/test.txt ,first line is "data:myscripts:20:30".How to
view only minutes(last field, 30).
\vspace{5pt}
\begin{itemize}
\item cut -d : -f 4 /home/test.txt
\item cut -f 3 /home/test.txt
\item cut -d : -f 3 /home/test.txt
\item None of these
\end{itemize}
\end{enumerate}
\end{frame}
\begin{frame}
\frametitle{Solutions}
\label{sec-10}
\begin{enumerate}
\item False
\vspace{15pt}
\item cut -d : -f 4 /home/test.txt
\end{enumerate}
\end{frame}
\begin{frame}
\begin{block}{}
\begin{center}
\textcolor{blue}{\Large THANK YOU!}
\end{center}
\end{block}
\begin{block}{}
\begin{center}
For more Information, visit our website\\
\url{http://fossee.in/}
\end{center}
\end{block}
\end{frame}
\end{document}
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