source: clfs-sysroot/BOOK/final-preps/creatingfiles.xml @ 02095ae

Last change on this file since 02095ae was 02095ae, checked in by Jim Gifford <clfs@…>, 14 years ago

r3633@server (orig r1649): jciccone | 2006-05-25 16:48:42 -0700
Added the Initial clfs-2.0 branch using sysroot builds.

  • Property mode set to 100644
File size: 3.5 KB
Line 
1<?xml version="1.0" encoding="ISO-8859-1"?>
2<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
3  "http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd" [
4  <!ENTITY % general-entities SYSTEM "../general.ent">
5  %general-entities;
6]>
7
8<sect1 id="ch-final-preps-creatingfiles">
9  <?dbhtml filename="creatingfiles.html"?>
10
11  <title>Creating Essential Files</title>
12
13  <para>A proper Linux system maintains a list of the mounted file systems in
14  the file <filename>/etc/mtab</filename>.  Normally, this file would be
15  created when we mount a new file system. Since we will not be mounting any
16  file systems inside our chroot environment, create an empty file for
17  utilities that expect the presence of <filename>/etc/mtab</filename>:</para>
18
19<screen><userinput>touch ${LFS}/etc/mtab</userinput></screen>
20
21  <para>In order for user <systemitem class="username">root</systemitem> to be
22  able to login and for the name <quote>root</quote> to be recognized, there
23  must be relevant entries in the <filename>/etc/passwd</filename> and
24  <filename>/etc/group</filename> files.</para>
25
26  <para>Create the <filename>/etc/passwd</filename> file by running the following
27  command:</para>
28
29<screen><userinput>cat &gt; %{LFS}/etc/passwd &lt;&lt; "EOF"
30<literal>root:x:0:0:root:/root:/bin/bash</literal>
31EOF</userinput></screen>
32
33  <para>The actual password for <systemitem class="username">root</systemitem>
34  (the <quote>x</quote> used here is just a placeholder) will be set later.</para>
35
36  <para>Create the <filename>/etc/group</filename> file by running the following
37  command:</para>
38
39<screen><userinput>cat &gt; ${LFS}/etc/group &lt;&lt; "EOF"
40<literal>root:x:0:
41bin:x:1:
42sys:x:2:
43kmem:x:3:
44tty:x:4:
45tape:x:5:
46daemon:x:6:
47floppy:x:7:
48disk:x:8:
49lp:x:9:
50dialout:x:10:
51audio:x:11:
52video:x:12:
53utmp:x:13:
54usb:x:14:
55cdrom:x:15:</literal>
56EOF</userinput></screen>
57
58  <para>The created groups are not part of any standard&mdash;they are groups
59  decided on in part by the requirements of the Udev configuration in this
60  chapter, and in part by common convention employed by a number of existing
61  Linux distributions. The Linux Standard Base (LSB, available at <ulink
62  url="http://www.linuxbase.org"/>) recommends only that, besides the group
63  <systemitem class="groupname">root</systemitem> with a Group ID (GID) of 0,
64  a group <systemitem class="groupname">bin</systemitem> with a GID of 1 be
65  present. All other group names and GIDs can be chosen freely by the system
66  administrator since well-written programs do not depend on GID numbers, but
67  rather use the group's name.</para>
68
69  <para>The <command>login</command>, <command>agetty</command>, and
70  <command>init</command> programs (and others) use a number of log
71  files to record information such as who was logged into the system and
72  when. However, these programs will not write to the log files if they
73  do not already exist. Initialize the log files and give them
74  proper permissions:</para>
75
76<screen><userinput>touch ${LFS}/var/run/utmp ${LFS}/var/log/{btmp,lastlog,wtmp}
77chgrp -v utmp ${LFS}/var/run/utmp ${LFS}/var/log/lastlog
78chmod -v 664 ${LFS}/var/run/utmp ${LFS}/var/log/lastlog</userinput></screen>
79
80  <para>The <filename>/var/run/utmp</filename> file records the users
81  that are currently logged in. The <filename>/var/log/wtmp</filename>
82  file records all logins and logouts. The
83  <filename>/var/log/lastlog</filename> file records when
84  each user last logged in. The <filename>/var/log/btmp</filename> file
85  records the bad login attempts.</para>
86
87</sect1>
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