diff options
Diffstat (limited to 'slackbook/html/shell.html')
| -rw-r--r-- | slackbook/html/shell.html | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/slackbook/html/shell.html b/slackbook/html/shell.html new file mode 100644 index 00000000..aa259c8c --- /dev/null +++ b/slackbook/html/shell.html @@ -0,0 +1,166 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" + "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml"> +<head> +<meta name="generator" content="HTML Tidy, see www.w3.org" /> +<title>The Shell</title> +<meta name="GENERATOR" content="Modular DocBook HTML Stylesheet Version 1.7" /> +<link rel="HOME" title="Slackware Linux Essentials" href="index.html" /> +<link rel="PREVIOUS" title="Dual Booting" href="booting-dual.html" /> +<link rel="NEXT" title="The Command Line" href="shell-command-line.html" /> +<link rel="STYLESHEET" type="text/css" href="docbook.css" /> +<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> +</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">Slackware Linux Essentials</th> +</tr> + +<tr> +<td width="10%" align="left" valign="bottom"><a href="booting-dual.html" +accesskey="P">Prev</a></td> +<td width="80%" align="center" valign="bottom"></td> +<td width="10%" align="right" valign="bottom"><a href="shell-command-line.html" +accesskey="N">Next</a></td> +</tr> +</table> + +<hr align="LEFT" width="100%" /> +</div> + +<div class="CHAPTER"> +<h1><a id="SHELL" name="SHELL"></a>Chapter 8 The Shell</h1> + +<div class="TOC"> +<dl> +<dt><b>Table of Contents</b></dt> + +<dt>8.1 <a href="shell.html#SHELL-USERS">Users</a></dt> + +<dt>8.2 <a href="shell-command-line.html">The Command Line</a></dt> + +<dt>8.3 <a href="shell-bash.html">The Bourne Again Shell (bash)</a></dt> + +<dt>8.4 <a href="shell-vt.html">Virtual Terminals</a></dt> +</dl> +</div> + +<p>In a graphical environment, the interface is provided by a program that creates +windows, scrollbars, menus, etc. In a commandline environment, the user interface is +provided by a shell, which interprets commands and generally makes things useable. +Immediately after logging in (which is covered in this chapter), users are put into a +shell and allowed to go about their business. This chapter serves as an introduction to +the shell, and to the most common shell among Linux users-- the Bourne Again Shell +(bash). For more detailed information on anything in this chapter, check out the <tt +class="COMMAND">bash</tt>(1) man page.</p> + +<div class="SECT1"> +<h1 class="SECT1"><a id="SHELL-USERS" name="SHELL-USERS">8.1 Users</a></h1> + +<div class="SECT2"> +<h2 class="SECT2"><a id="AEN2678" name="AEN2678">8.1.1 Logging In</a></h2> + +<p>So you've booted, and you're looking at something that looks like this:</p> + +<table border="0" bgcolor="#E0E0E0" width="100%"> +<tr> +<td> +<pre class="SCREEN"> +Welcome to Linux 2.4.18 +Last login: Wed Jan 1 15:59:14 -0500 2005 on tty6. +darkstar login: +</pre> +</td> +</tr> +</table> + +<p>Hmm.. nobody said anything about a login. And what's a darkstar? Don't worry; you +probably didn't accidentally fire up a hyperspace comm-link to the Empire's artificial +moon. (I'm afraid the hyperspace comm-link protocol isn't currently supported by the +Linux kernel. Maybe the 2.8 kernel branch will at last provide this oft looked-for +support.) No, darkstar is just the name of one of our computers, and its name gets +stamped on as the default. If you specified a name for your computer during setup, you +should see it instead of darkstar.</p> + +<p>As for the login... If this is your first time, you'll want to log in as <tt +class="USERNAME">root</tt>. You'll be prompted for a password; if you set one during the +setup process, that's what it's looking for. If not, just hit enter. That's it-- you're +in!</p> +</div> + +<div class="SECT2"> +<h2 class="SECT2"><a id="AEN2693" name="AEN2693">8.1.2 Root: The Superuser</a></h2> + +<p>Okay, who or <span class="emphasis"><i class="EMPHASIS">what</i></span> is <tt +class="USERNAME">root</tt>? And what's it doing with an account on <span +class="emphasis"><i class="EMPHASIS">your</i></span> system?</p> + +<p>Well, in the world of Unix and similar operating systems (like Linux), there are users +and then there are users. We'll go into this in more detail later, but the important +thing to know now is that <tt class="USERNAME">root</tt> is the user above all users; <tt +class="USERNAME">root</tt> is all-powerful and all-knowing, and <span class="emphasis"><i +class="EMPHASIS">nobody</i></span> disobeys <tt class="USERNAME">root</tt>. It just isn't +allowed. <tt class="USERNAME">root</tt> is what we call a “superuser”, and +rightly so. And best of all, <tt class="USERNAME">root</tt> is <span class="emphasis"><i +class="EMPHASIS">you</i></span>.</p> + +<p>Cool, huh?</p> + +<p>If you're not sure: yes, that's very cool. The catch is, though, that root is +inherently allowed to break anything it so desires. You might want to skip ahead to <a +href="essential-sysadmin.html#ESSENTIAL-SYSADMIN-USERS-SCRIPTS">Section 12.1.1</a> and +see about adding a user; then login as that user and work from there. The traditional +wisdom is that it's best to only become the superuser when absolutely necessary, so as to +minimize the possibility of accidentally breaking something.</p> + +<p>By the way, if you decide you want to be root while you're logged in as someone else, +no problem. Just use the <tt class="COMMAND">su</tt>(1) command. You'll be asked for <tt +class="USERNAME">root's</tt> password and then it will make you <tt +class="USERNAME">root</tt> until you <tt class="COMMAND">exit</tt> or <tt +class="COMMAND">logout</tt>. You can also become any other user using <tt +class="COMMAND">su</tt>, provided you know that user's password: <tt class="COMMAND">su +logan</tt>, for instance, would make you me.</p> + +<div class="NOTE"> +<table class="NOTE" width="100%" border="0"> +<tr> +<td width="25" align="CENTER" valign="TOP"><img src="./imagelib/admon/note.png" +hspace="5" alt="Note" /></td> +<td align="LEFT" valign="TOP"> +<p><tt class="USERNAME">root</tt> is allowed to su to any user, without requiring their +password.</p> +</td> +</tr> +</table> +</div> +</div> +</div> +</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="booting-dual.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="shell-command-line.html" +accesskey="N">Next</a></td> +</tr> + +<tr> +<td width="33%" align="left" valign="top">Dual Booting</td> +<td width="34%" align="center" valign="top"> </td> +<td width="33%" align="right" valign="top">The Command Line</td> +</tr> +</table> +</div> +</body> +</html> + |