271 lines
4.0 KiB
HTML
271 lines
4.0 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
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<HTML
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><HEAD
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><TITLE
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>Performing more than one command</TITLE
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><META
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NAME="GENERATOR"
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CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
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REL="HOME"
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TITLE="GNU/Linux Command-Line Tools Summary"
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HREF="index.html"><LINK
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REL="UP"
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TITLE="Directing Input/Output"
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HREF="directing-input-ouput.html"><LINK
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REL="PREVIOUS"
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TITLE="Command Substitution"
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HREF="command-substitution.html"><LINK
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REL="NEXT"
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TITLE="Working with the file-system"
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HREF="working-with-the-file-system.html"></HEAD
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><BODY
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CLASS="SECT1"
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BGCOLOR="#FFFFFF"
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TEXT="#000000"
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LINK="#0000FF"
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VLINK="#840084"
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ALINK="#0000FF"
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><DIV
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CLASS="NAVHEADER"
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><TABLE
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SUMMARY="Header navigation table"
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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><TR
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><TH
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COLSPAN="3"
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ALIGN="center"
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>GNU/Linux Command-Line Tools Summary</TH
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></TR
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><TR
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><TD
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WIDTH="10%"
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ALIGN="left"
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VALIGN="bottom"
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><A
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HREF="command-substitution.html"
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ACCESSKEY="P"
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>Prev</A
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></TD
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><TD
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WIDTH="80%"
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ALIGN="center"
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VALIGN="bottom"
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>Chapter 6. Directing Input/Output</TD
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><TD
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WIDTH="10%"
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ALIGN="right"
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VALIGN="bottom"
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><A
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HREF="working-with-the-file-system.html"
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ACCESSKEY="N"
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>Next</A
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></TD
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></TR
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></TABLE
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><HR
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ALIGN="LEFT"
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WIDTH="100%"></DIV
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><DIV
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CLASS="SECT1"
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><H1
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CLASS="SECT1"
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><A
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NAME="PERFORMING-MORE-THAN-ONE-COMMAND"
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></A
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>6.4. Performing more than one command</H1
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><P
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></P
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><DIV
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CLASS="VARIABLELIST"
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><DL
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><DT
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>Executing the second command only if the first is successful<A
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NAME="EXECUTE-COMMAND-2-IF-1-WORKS"
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></A
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></DT
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><DD
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><P
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> </P
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><P
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>To do this you would type:</P
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><TABLE
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BORDER="1"
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BGCOLOR="#E0E0E0"
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WIDTH="90%"
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><TR
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><TD
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><FONT
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COLOR="#000000"
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><PRE
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CLASS="SCREEN"
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>command1 && command2</PRE
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></FONT
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></TD
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></TR
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></TABLE
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><P
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>command2 will be executed if command1 successfully completes (if command1 fails command2 won't be run). This is called a logical AND.</P
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></DD
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><DT
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>Executing the second command only if the first fails<A
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NAME="EXECUTE-COMMAND-2-IF-1-FAILS"
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></A
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></DT
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><DD
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><P
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> </P
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><P
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>To do this you would type:</P
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><TABLE
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BORDER="1"
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BGCOLOR="#E0E0E0"
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WIDTH="90%"
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><TR
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><TD
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><FONT
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COLOR="#000000"
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><PRE
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CLASS="SCREEN"
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>command1 || command2</PRE
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></FONT
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></TD
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></TR
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></TABLE
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><P
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>command2 will be executed if command1 does not successfully complete (if command1 is successful command2 won't be run). This is called a logical OR.</P
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></DD
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><DT
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>Executing commands sequentially<A
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NAME="EXECUTING-COMMANDS-SEQUENTIALLY"
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></A
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></DT
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><DD
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><P
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> </P
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><P
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>To execute commands sequentially regardless of the success/failure of the previous you simply type:</P
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><TABLE
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BORDER="1"
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BGCOLOR="#E0E0E0"
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WIDTH="90%"
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><TR
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><TD
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><FONT
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COLOR="#000000"
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><PRE
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CLASS="SCREEN"
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>command1; command2</PRE
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></FONT
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></TD
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></TR
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></TABLE
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><P
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>command2 will execute once command1 has completed.</P
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><DIV
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CLASS="TIP"
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><P
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></P
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><TABLE
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CLASS="TIP"
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WIDTH="90%"
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BORDER="0"
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><TR
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><TD
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WIDTH="25"
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ALIGN="CENTER"
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VALIGN="TOP"
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><IMG
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SRC="../images/tip.gif"
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HSPACE="5"
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ALT="Tip"></TD
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><TH
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ALIGN="LEFT"
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VALIGN="CENTER"
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><B
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>More than two commands</B
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></TH
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></TR
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><TR
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><TD
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> </TD
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><TD
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ALIGN="LEFT"
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VALIGN="TOP"
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><P
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>You can continue to use ';' (semicolon) characters to do more and more commands on the one line.</P
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></TD
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></TR
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></TABLE
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></DIV
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></DD
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></DL
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></DIV
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></DIV
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><DIV
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CLASS="NAVFOOTER"
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><HR
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ALIGN="LEFT"
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WIDTH="100%"><TABLE
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SUMMARY="Footer navigation table"
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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><A
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HREF="command-substitution.html"
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ACCESSKEY="P"
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>Prev</A
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></TD
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||
><TD
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||
WIDTH="34%"
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||
ALIGN="center"
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||
VALIGN="top"
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||
><A
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||
HREF="index.html"
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ACCESSKEY="H"
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>Home</A
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></TD
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||
><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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><A
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HREF="working-with-the-file-system.html"
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ACCESSKEY="N"
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>Next</A
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></TD
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||
></TR
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||
><TR
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||
><TD
|
||
WIDTH="33%"
|
||
ALIGN="left"
|
||
VALIGN="top"
|
||
>Command Substitution</TD
|
||
><TD
|
||
WIDTH="34%"
|
||
ALIGN="center"
|
||
VALIGN="top"
|
||
><A
|
||
HREF="directing-input-ouput.html"
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ACCESSKEY="U"
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>Up</A
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||
></TD
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||
><TD
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||
WIDTH="33%"
|
||
ALIGN="right"
|
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VALIGN="top"
|
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>Working with the file-system</TD
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></TR
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></TABLE
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></DIV
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></BODY
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></HTML
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> |