348 lines
4.3 KiB
HTML
348 lines
4.3 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
|
|
<HTML
|
|
><HEAD
|
|
><TITLE
|
|
>Repetitive tasks</TITLE
|
|
><META
|
|
NAME="GENERATOR"
|
|
CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
|
|
REL="HOME"
|
|
TITLE="Bash Guide for Beginners"
|
|
HREF="index.html"><LINK
|
|
REL="PREVIOUS"
|
|
TITLE="Exercises"
|
|
HREF="sect_08_04.html"><LINK
|
|
REL="NEXT"
|
|
TITLE="The for loop"
|
|
HREF="sect_09_01.html"></HEAD
|
|
><BODY
|
|
CLASS="chapter"
|
|
BGCOLOR="#FFFFFF"
|
|
TEXT="#000000"
|
|
LINK="#0000FF"
|
|
VLINK="#840084"
|
|
ALINK="#0000FF"
|
|
><DIV
|
|
CLASS="NAVHEADER"
|
|
><TABLE
|
|
SUMMARY="Header navigation table"
|
|
WIDTH="100%"
|
|
BORDER="0"
|
|
CELLPADDING="0"
|
|
CELLSPACING="0"
|
|
><TR
|
|
><TH
|
|
COLSPAN="3"
|
|
ALIGN="center"
|
|
>Bash Guide for Beginners</TH
|
|
></TR
|
|
><TR
|
|
><TD
|
|
WIDTH="10%"
|
|
ALIGN="left"
|
|
VALIGN="bottom"
|
|
><A
|
|
HREF="sect_08_04.html"
|
|
ACCESSKEY="P"
|
|
>Prev</A
|
|
></TD
|
|
><TD
|
|
WIDTH="80%"
|
|
ALIGN="center"
|
|
VALIGN="bottom"
|
|
></TD
|
|
><TD
|
|
WIDTH="10%"
|
|
ALIGN="right"
|
|
VALIGN="bottom"
|
|
><A
|
|
HREF="sect_09_01.html"
|
|
ACCESSKEY="N"
|
|
>Next</A
|
|
></TD
|
|
></TR
|
|
></TABLE
|
|
><HR
|
|
ALIGN="LEFT"
|
|
WIDTH="100%"></DIV
|
|
><DIV
|
|
CLASS="chapter"
|
|
><H1
|
|
><A
|
|
NAME="chap_09"
|
|
></A
|
|
>Chapter 9. Repetitive tasks</H1
|
|
><DIV
|
|
CLASS="TOC"
|
|
><DL
|
|
><DT
|
|
><B
|
|
>Table of Contents</B
|
|
></DT
|
|
><DT
|
|
>9.1. <A
|
|
HREF="sect_09_01.html"
|
|
>The for loop</A
|
|
></DT
|
|
><DD
|
|
><DL
|
|
><DT
|
|
>9.1.1. <A
|
|
HREF="sect_09_01.html#sect_09_01_01"
|
|
>How does it work?</A
|
|
></DT
|
|
><DT
|
|
>9.1.2. <A
|
|
HREF="sect_09_01.html#sect_09_01_02"
|
|
>Examples</A
|
|
></DT
|
|
></DL
|
|
></DD
|
|
><DT
|
|
>9.2. <A
|
|
HREF="sect_09_02.html"
|
|
>The while loop</A
|
|
></DT
|
|
><DD
|
|
><DL
|
|
><DT
|
|
>9.2.1. <A
|
|
HREF="sect_09_02.html#sect_09_02_01"
|
|
>What is it?</A
|
|
></DT
|
|
><DT
|
|
>9.2.2. <A
|
|
HREF="sect_09_02.html#sect_09_02_02"
|
|
>Examples</A
|
|
></DT
|
|
></DL
|
|
></DD
|
|
><DT
|
|
>9.3. <A
|
|
HREF="sect_09_03.html"
|
|
>The until loop</A
|
|
></DT
|
|
><DD
|
|
><DL
|
|
><DT
|
|
>9.3.1. <A
|
|
HREF="sect_09_03.html#sect_09_03_01"
|
|
>What is it?</A
|
|
></DT
|
|
><DT
|
|
>9.3.2. <A
|
|
HREF="sect_09_03.html#sect_09_03_02"
|
|
>Example</A
|
|
></DT
|
|
></DL
|
|
></DD
|
|
><DT
|
|
>9.4. <A
|
|
HREF="sect_09_04.html"
|
|
>I/O redirection and loops</A
|
|
></DT
|
|
><DD
|
|
><DL
|
|
><DT
|
|
>9.4.1. <A
|
|
HREF="sect_09_04.html#sect_09_04_01"
|
|
>Input redirection</A
|
|
></DT
|
|
><DT
|
|
>9.4.2. <A
|
|
HREF="sect_09_04.html#sect_09_04_02"
|
|
>Output redirection</A
|
|
></DT
|
|
></DL
|
|
></DD
|
|
><DT
|
|
>9.5. <A
|
|
HREF="sect_09_05.html"
|
|
>Break and continue</A
|
|
></DT
|
|
><DD
|
|
><DL
|
|
><DT
|
|
>9.5.1. <A
|
|
HREF="sect_09_05.html#sect_09_05_01"
|
|
>The break built-in</A
|
|
></DT
|
|
><DT
|
|
>9.5.2. <A
|
|
HREF="sect_09_05.html#sect_09_05_02"
|
|
>The continue built-in</A
|
|
></DT
|
|
><DT
|
|
>9.5.3. <A
|
|
HREF="sect_09_05.html#sect_09_05_03"
|
|
>Examples</A
|
|
></DT
|
|
></DL
|
|
></DD
|
|
><DT
|
|
>9.6. <A
|
|
HREF="sect_09_06.html"
|
|
>Making menus with the select built-in</A
|
|
></DT
|
|
><DD
|
|
><DL
|
|
><DT
|
|
>9.6.1. <A
|
|
HREF="sect_09_06.html#sect_09_06_01"
|
|
>General</A
|
|
></DT
|
|
><DT
|
|
>9.6.2. <A
|
|
HREF="sect_09_06.html#sect_09_06_02"
|
|
>Submenus</A
|
|
></DT
|
|
></DL
|
|
></DD
|
|
><DT
|
|
>9.7. <A
|
|
HREF="sect_09_07.html"
|
|
>The shift built-in</A
|
|
></DT
|
|
><DD
|
|
><DL
|
|
><DT
|
|
>9.7.1. <A
|
|
HREF="sect_09_07.html#sect_09_07_01"
|
|
>What does it do?</A
|
|
></DT
|
|
><DT
|
|
>9.7.2. <A
|
|
HREF="sect_09_07.html#sect_09_07_02"
|
|
>Examples</A
|
|
></DT
|
|
></DL
|
|
></DD
|
|
><DT
|
|
>9.8. <A
|
|
HREF="sect_09_08.html"
|
|
>Summary</A
|
|
></DT
|
|
><DT
|
|
>9.9. <A
|
|
HREF="sect_09_09.html"
|
|
>Exercises</A
|
|
></DT
|
|
></DL
|
|
></DIV
|
|
><BLOCKQUOTE
|
|
CLASS="ABSTRACT"
|
|
><DIV
|
|
CLASS="abstract"
|
|
><A
|
|
NAME="AEN5864"
|
|
></A
|
|
><P
|
|
></P
|
|
><P
|
|
>Upon completion of this chapter, you will be able to</P
|
|
><P
|
|
> <P
|
|
></P
|
|
><UL
|
|
><LI
|
|
><P
|
|
>Use <B
|
|
CLASS="command"
|
|
>for</B
|
|
>, <B
|
|
CLASS="command"
|
|
>while</B
|
|
> and <B
|
|
CLASS="command"
|
|
>until</B
|
|
> loops, and decide which loop fits which occasion.</P
|
|
></LI
|
|
><LI
|
|
><P
|
|
>Use the <B
|
|
CLASS="command"
|
|
>break</B
|
|
> and <B
|
|
CLASS="command"
|
|
>continue</B
|
|
> Bash built-ins.</P
|
|
></LI
|
|
><LI
|
|
><P
|
|
>Write scripts using the <B
|
|
CLASS="command"
|
|
>select</B
|
|
> statement.</P
|
|
></LI
|
|
><LI
|
|
><P
|
|
>Write scripts that take a variable number of arguments.</P
|
|
></LI
|
|
></UL
|
|
></P
|
|
><P
|
|
></P
|
|
></DIV
|
|
></BLOCKQUOTE
|
|
></DIV
|
|
><DIV
|
|
CLASS="NAVFOOTER"
|
|
><HR
|
|
ALIGN="LEFT"
|
|
WIDTH="100%"><TABLE
|
|
SUMMARY="Footer navigation table"
|
|
WIDTH="100%"
|
|
BORDER="0"
|
|
CELLPADDING="0"
|
|
CELLSPACING="0"
|
|
><TR
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="left"
|
|
VALIGN="top"
|
|
><A
|
|
HREF="sect_08_04.html"
|
|
ACCESSKEY="P"
|
|
>Prev</A
|
|
></TD
|
|
><TD
|
|
WIDTH="34%"
|
|
ALIGN="center"
|
|
VALIGN="top"
|
|
><A
|
|
HREF="index.html"
|
|
ACCESSKEY="H"
|
|
>Home</A
|
|
></TD
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="right"
|
|
VALIGN="top"
|
|
><A
|
|
HREF="sect_09_01.html"
|
|
ACCESSKEY="N"
|
|
>Next</A
|
|
></TD
|
|
></TR
|
|
><TR
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="left"
|
|
VALIGN="top"
|
|
>Exercises</TD
|
|
><TD
|
|
WIDTH="34%"
|
|
ALIGN="center"
|
|
VALIGN="top"
|
|
> </TD
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="right"
|
|
VALIGN="top"
|
|
>The for loop</TD
|
|
></TR
|
|
></TABLE
|
|
></DIV
|
|
></BODY
|
|
></HTML
|
|
> |