From d8cc8d7f5aa2628de982f5d2aa3eec71e8b5746e Mon Sep 17 00:00:00 2001
From: John Ogness <john.ogness@linutronix.de>
Date: Fri, 31 Aug 2018 15:16:34 +0206
Subject: sh-programming: add english translation

Signed-off-by: John Ogness <john.ogness@linutronix.de>
---
 .../sh-programming/pres_sh-programming_en.tex      | 316 +++++++++++++++++++++
 1 file changed, 316 insertions(+)
 create mode 100644 linux-basics/sh-programming/pres_sh-programming_en.tex

(limited to 'linux-basics/sh-programming/pres_sh-programming_en.tex')

diff --git a/linux-basics/sh-programming/pres_sh-programming_en.tex b/linux-basics/sh-programming/pres_sh-programming_en.tex
new file mode 100644
index 0000000..1e6202f
--- /dev/null
+++ b/linux-basics/sh-programming/pres_sh-programming_en.tex
@@ -0,0 +1,316 @@
+\input{configpres}
+
+\title{Introduction to Shell Programming}
+\maketitle
+
+\begin{frame}
+\frametitle{Components of a Script}
+\begin{itemize}
+\item syntax: "\#!/some/interpreter"
+\pause
+\item any program can be specified as the interpreter
+\pause
+\item example: "\#!/bin/sh"
+\pause
+\item followed by shell commands (for a shell interpreter)
+\end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Hello World as Shell Script}
+\begin{lstlisting}
+#!/bin/sh
+
+echo 'Hello, world!'
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Variables}
+\begin{lstlisting}
+#!/bin/sh
+
+# VAR1 defined for this process
+VAR1=abc
+
+# set export property of VAR1 for this process
+# (now VAR1 is defined for future children processes)
+export VAR1
+
+# VAR2 defined only for /bin/sh child process
+# (with export property set)
+VAR2=def /bin/sh
+
+# clear export property of VAR1 for this process
+export -n VAR1
+
+# undefine VAR1 for this process
+unset VAR1
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Variables}
+\begin{lstlisting}
+#!/bin/sh
+
+VAR1=abc
+VAR1="a b c"
+
+echo $VAR1
+echo ${VAR1}
+echo "${VAR1}"
+echo '${VAR1}'
+
+VAR1=`date`
+VAR1=$(date)
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}
+\frametitle{Special Variables}
+\begin{description}
+\item[\$0] argv[0]
+\item[\$1] argv[1]
+\item[\$2] argv[2]
+\item[\$\#] argc
+\item[\$@] all arguments together as a string
+\item[\$\$] my PID
+\item[\$?] return value of most recent executed command
+\end{description}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Example Script}
+\begin{lstlisting}
+#!/bin/sh
+
+MY_VAR=17
+PAR_1=$1
+now=`date`
+
+echo variable is ${MYVAR}, parameter is ${PAR_1}
+echo date is $now
+echo hostname of this machine is $(hostname)
+echo 
+\end{lstlisting}
+
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Output Redirection}
+\begin{lstlisting}
+#!/bin/sh
+
+# How many lines in addr.txt contain "Jones" ?
+# Store the result in "jones_count"
+grep Jones addr.txt | wc -l > jones_count
+
+# Append a message to a log file
+echo "My message" >> log_file
+\end{lstlisting}
+
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Conditional Branching}
+\begin{lstlisting}
+#!/bin/sh
+
+if [ condition ]
+then
+    ...
+else
+    ...
+fi
+
+# in one line...
+
+if [ condition]; then ...; fi
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Conditional Branching}
+\begin{lstlisting}
+#!/bin/sh
+
+# number tests: -eq -ne -lt -gt -le -ge
+num=15
+if [ $num -lt 20 ]; then ...; fi
+
+# string tests: = != < > -n -z
+string="Hello"
+if [ $string != "hello" ]; then ...; fi
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Conditional Branching}
+\begin{lstlisting}
+#!/bin/sh
+
+# file tests:
+# -f is a normal file
+# -d is a directory
+# -e exists
+# -s exists and is not empty
+# -r is readable
+# -w is writable
+# -x is executable
+# -b is a block device
+# -c is a character device
+filename="myfile"
+if [ -f $filename ]; then ...; fi
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Conditional Branching}
+\begin{lstlisting}
+#!/bin/sh
+
+# all tests can be negated with '!'
+filename="myfile"
+if [ ! -f $filename ]; then ...; fi
+
+# tests can be combined with a logical and '-a' and or '-o'
+filename="myfile"
+num=15
+string="Hello"
+if [ -f $filename -o ! $num -lt 20 -a $string != "hello" ]; then ...; fi
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Conditional Branching}
+\begin{lstlisting}
+#!/bin/sh
+
+# Does addr.txt contain "Jones" ?
+if grep Jones addr.txt; then ...
+
+# Return value 0 means OK
+exit 0
+
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Conditional Branching}
+\begin{lstlisting}
+#!/bin/sh
+
+VAR=abcdef
+
+case $VAR in
+abc)
+    echo "exactly abc"
+    ;;
+abcdef)
+    echo "exactly abcdef"
+    ;;
+abc*)
+    echo "begins with abc"
+    ;;
+*)
+    echo "match everything"
+    ;;
+esac
+
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Conditional Branching}
+\begin{lstlisting}
+#!/bin/sh
+
+# short circuit tests:
+
+make && make install
+
+grep Jones addr.txt || echo "No Jones found!"
+
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Loops}
+\begin{lstlisting}
+#!/bin/sh
+
+for filename in file1 file2 file3
+do
+    cp $filename $filename.bak
+done
+
+for filename in *
+do
+    ...
+done
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Loops}
+\begin{lstlisting}
+#!/bin/sh
+
+while [ condition ]
+do
+    ...
+done
+
+while [ condition ]; do ...; done
+
+# "while conditions" are the same as "if conditions"
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Functions}
+\begin{lstlisting}
+#!/bin/sh
+
+error_log() {
+    echo "Error: $1" >> my_log_file
+}
+
+...
+
+error_log "file not found"
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Using External Scripts}
+\begin{lstlisting}
+#!/bin/sh
+
+# include an external script
+. /path/to/my_other_script
+
+# run an external script
+/path/to/my_other_script
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Accessing Files}
+\begin{lstlisting}
+#!/bin/sh
+
+ls -1 > filelist.txt
+
+while read filename
+do
+    if [ -d $filename ]
+    then
+        echo "$filename is a directory"
+    fi
+done < filelist.txt
+\end{lstlisting}
+\end{frame}
+
+\input{tailpres}
-- 
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