242 lines
4.1 KiB
HTML
242 lines
4.1 KiB
HTML
<HTML
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><HEAD
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><TITLE
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>The First Step</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="Bash Prompt HOWTO"
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HREF="index.html"><LINK
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REL="UP"
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TITLE="Bash and Bash Prompts"
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HREF="c141.html"><LINK
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REL="PREVIOUS"
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TITLE="Why Bother?"
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HREF="x152.html"><LINK
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REL="NEXT"
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TITLE="Bash Prompt Escape Sequences"
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HREF="bash-prompt-escape-sequences.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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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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>Bash Prompt HOWTO: </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="x152.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 2. Bash and Bash Prompts</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="bash-prompt-escape-sequences.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="AEN157"
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></A
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>2.4. The First Step</H1
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><P
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>The appearance of the prompt is governed by the shell variable PS1.
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Command continuations are indicated by the PS2 string, which can be
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modified in exactly the same ways discussed here - since controlling it is
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exactly the same, and it isn't as "interesting," I'll mostly be modifying
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the PS1 string. (There are also PS3 and PS4 strings. These are never seen
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by the average user - see the Bash man page if you're interested in their
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purpose.) To change the way the prompt looks, you change the PS1 variable.
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For experimentation purposes, you can enter the PS1 strings directly at the
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prompt, and see the results immediately (this only affects your current
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session, and the changes go away when you exit the current shell). If you
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want to make a change to the prompt permanent, look at the section below
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<A
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HREF="setps.html"
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>Section 2.6</A
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>. </P
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><P
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>Before we get started, it's important to remember that the PS1 string is
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stored in the environment like any other environment variable. If you
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modify it at the command line, your prompt will change. Before you make
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any changes, you can save your current prompt to another environment
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variable:</P
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><TABLE
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BORDER="1"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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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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>[giles@nikola giles]$ SAVE=$PS1
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[giles@nikola giles]$</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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>The simplest prompt would be a single character, such as:</P
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><TABLE
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BORDER="1"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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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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>[giles@nikola giles]$ PS1=$
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$ls
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bin mail
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$</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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>This demonstrates the best way to experiment with basic prompts, entering
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them at the command line. Notice that the text entered by the user
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appears immediately after the prompt: I prefer to use </P
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><TABLE
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BORDER="1"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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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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>$PS1="$ "
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$ ls
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bin mail
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$ </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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>which forces a space after the prompt, making it more readable. To restore
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your original prompt, just call up the variable you stored:</P
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><TABLE
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BORDER="1"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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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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>$ PS1=$SAVE
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[giles@nikola giles]$</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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></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="x152.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="bash-prompt-escape-sequences.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
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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>Why Bother?</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="c141.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%"
|
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ALIGN="right"
|
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VALIGN="top"
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>Bash Prompt Escape Sequences</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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> |