source: clfs-sysroot/BOOK/final-preps/creatingfiles.xml@ 708835f

Last change on this file since 708835f was c439b8a, checked in by Manuel Canales Esparcia <manuel@…>, 18 years ago

Updated CLFS-Sysroot book sources to use DocBook-XML DTD 4.5.

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[02095ae]1<?xml version="1.0" encoding="ISO-8859-1"?>
[c439b8a]2<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3 "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
[02095ae]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
[3349a3a]11 <title>Creating the passwd, group, and log Files</title>
12
13 <indexterm zone="ch-final-preps-creatingfiles">
14 <primary sortas="e-/etc/passwd">/etc/passwd</primary>
15 </indexterm>
16
17 <indexterm zone="ch-final-preps-creatingfiles">
18 <primary sortas="e-/etc/group">/etc/group</primary>
19 </indexterm>
20
21 <indexterm zone="ch-final-preps-creatingfiles">
22 <primary sortas="e-/var/run/utmp">/var/run/utmp</primary>
23 </indexterm>
24
25 <indexterm zone="ch-final-preps-creatingfiles">
[599e966]26 <primary sortas="e-/var/log/btmp">/var/log/btmp</primary>
[3349a3a]27 </indexterm>
28
29 <indexterm zone="ch-final-preps-creatingfiles">
30 <primary sortas="e-/var/log/lastlog">/var/log/lastlog</primary>
31 </indexterm>
32
33 <indexterm zone="ch-final-preps-creatingfiles">
34 <primary sortas="e-/var/log/wtmp">/var/log/wtmp</primary>
35 </indexterm>
[02095ae]36
37 <para>In order for user <systemitem class="username">root</systemitem> to be
38 able to login and for the name <quote>root</quote> to be recognized, there
39 must be relevant entries in the <filename>/etc/passwd</filename> and
40 <filename>/etc/group</filename> files.</para>
41
42 <para>Create the <filename>/etc/passwd</filename> file by running the following
43 command:</para>
44
[586feb7]45<screen><userinput>cat &gt; ${CLFS}/etc/passwd &lt;&lt; "EOF"
[83baa46]46<literal>root::0:0:root:/root:/bin/bash</literal>
[02095ae]47EOF</userinput></screen>
48
49 <para>The actual password for <systemitem class="username">root</systemitem>
[599e966]50 (the <quote>::</quote> used here is just a placeholder and allow you to login
51 with no password) will be set later.</para>
[02095ae]52
[599e966]53 <variablelist os="b">
[f8100c0]54
[586feb7]55 <title>Additional users you may want to add:</title>
56
57 <varlistentry>
58 <term><literal>bin:x:1:1:bin:/bin:/bin/false</literal></term>
59 <listitem>
[b46c2f1]60 <para>Can be useful for compatibility with legacy applications.</para>
[586feb7]61 </listitem>
62 </varlistentry>
63 <varlistentry>
64 <term><literal>daemon:x:2:6:daemon:/sbin:/bin/false</literal></term>
65 <listitem>
[b46c2f1]66 <para>It is often recommended to use an unprivileged User ID/Group ID
67 for daemons in order to limit their access to the system.</para>
[586feb7]68 </listitem>
69 </varlistentry>
70 <varlistentry>
71 <term><literal>adm:x:3:16:adm:/var/adm:/bin/false</literal></term>
72 <listitem>
[23f9a66]73 <para>Was used for programs that performed administrative tasks.</para>
[586feb7]74 </listitem>
75 </varlistentry>
76 <varlistentry>
77 <term><literal>lp:x:10:9:lp:/var/spool/lp:/bin/false</literal></term>
78 <listitem>
[23f9a66]79 <para>Used by programs for printing.</para>
[586feb7]80 </listitem>
81 </varlistentry>
82 <varlistentry>
83 <term><literal>mail:x:30:30:mail:/var/mail:/bin/false</literal></term>
84 <listitem>
[23f9a66]85 <para>Often used by email programs.</para>
[586feb7]86 </listitem>
87 </varlistentry>
88 <varlistentry>
89 <term><literal>news:x:31:31:news:/var/spool/news:/bin/false</literal></term>
90 <listitem>
[23f9a66]91 <para>Often used for network news servers.</para>
[586feb7]92 </listitem>
93 </varlistentry>
94 <varlistentry>
95 <term><literal>uucp:x:32:32:uucp:/var/spool/uucp:/bin/false</literal></term>
96 <listitem>
[b46c2f1]97 <para>Often used for Unix-to-Unix Copy of files from one server to the next</para>
[586feb7]98 </listitem>
99 </varlistentry>
100 <varlistentry>
101 <term><literal>operator:x:50:0:operator:/root:/bin/bash</literal></term>
102 <listitem>
[23f9a66]103 <para>Often used to allow system operators to access the system.</para>
[586feb7]104 </listitem>
105 </varlistentry>
106 <varlistentry>
107 <term><literal>postmaster:x:51:30:postmaster:/var/spool/mail:/bin/false</literal></term>
108 <listitem>
[b46c2f1]109 <para>Generally used as an account that receives all the information of troubles with the mail server.</para>
[586feb7]110 </listitem>
111 </varlistentry>
112 <varlistentry>
113 <term><literal>nobody:x:65534:65534:nobody:/:/bin/false</literal></term>
114 <listitem>
[b46c2f1]115 <para>Used by NFS.</para>
[586feb7]116 </listitem>
117 </varlistentry>
118 </variablelist>
119
[02095ae]120 <para>Create the <filename>/etc/group</filename> file by running the following
121 command:</para>
122
[586feb7]123<screen><userinput>cat &gt; ${CLFS}/etc/group &lt;&lt; "EOF"
[02095ae]124<literal>root:x:0:
125bin:x:1:
126sys:x:2:
127kmem:x:3:
128tty:x:4:
129tape:x:5:
130daemon:x:6:
131floppy:x:7:
132disk:x:8:
133lp:x:9:
134dialout:x:10:
135audio:x:11:
136video:x:12:
137utmp:x:13:
138usb:x:14:
139cdrom:x:15:</literal>
140EOF</userinput></screen>
141
[586feb7]142 <variablelist os="c">
[f8100c0]143
[586feb7]144 <title>Additional groups you may want to add</title>
145
146 <varlistentry>
147 <term><literal>adm:x:16:root,adm,daemon</literal></term>
148 <listitem>
[23f9a66]149 <para>All users in this group are allowed to do administrative tasks</para>
[586feb7]150 </listitem>
151 </varlistentry>
152 <varlistentry>
153 <term><literal>console:x:17:</literal></term>
154 <listitem>
[23f9a66]155 <para>This group has direct access to the console</para>
[586feb7]156 </listitem>
157 </varlistentry>
158 <varlistentry>
159 <term><literal>cdrw:x:18:</literal></term>
160 <listitem>
[23f9a66]161 <para>This group is allowed to use the CDRW drive</para>
[586feb7]162 </listitem>
163 </varlistentry>
164 <varlistentry>
165 <term><literal>mail:x:30:mail</literal></term>
166 <listitem>
167 <para>Used by MTAs (Mail Transport Agents)</para>
168 </listitem>
169 </varlistentry>
170 <varlistentry>
171 <term><literal>news:x:31:news</literal></term>
172 <listitem>
[23f9a66]173 <para>Used by Network News Servers</para>
[586feb7]174 </listitem>
175 </varlistentry>
176 <varlistentry>
177 <term><literal>uucp:x:32:uucp</literal></term>
178 <listitem>
[b46c2f1]179 <para>Used by the Unix-to-Unix copy users</para>
[586feb7]180 </listitem>
181 </varlistentry>
182 <varlistentry>
183 <term><literal>users:x:100:</literal></term>
184 <listitem>
[599e966]185 <para>The default GID used by shadow for new users</para>
[586feb7]186 </listitem>
187 </varlistentry>
188 <varlistentry>
189 <term><literal>nogroup:x:65533:</literal></term>
190 <listitem>
[23f9a66]191 <para>This is a default group used by some programs that do not
192 require a group</para>
[586feb7]193 </listitem>
194 </varlistentry>
195 <varlistentry>
196 <term><literal>nobody:x:65534:</literal></term>
197 <listitem>
[b46c2f1]198 <para>This is used by NFS</para>
[586feb7]199 </listitem>
200 </varlistentry>
201 </variablelist>
202
[02095ae]203 <para>The created groups are not part of any standard&mdash;they are groups
204 decided on in part by the requirements of the Udev configuration in this
205 chapter, and in part by common convention employed by a number of existing
206 Linux distributions. The Linux Standard Base (LSB, available at <ulink
207 url="http://www.linuxbase.org"/>) recommends only that, besides the group
208 <systemitem class="groupname">root</systemitem> with a Group ID (GID) of 0,
209 a group <systemitem class="groupname">bin</systemitem> with a GID of 1 be
210 present. All other group names and GIDs can be chosen freely by the system
211 administrator since well-written programs do not depend on GID numbers, but
212 rather use the group's name.</para>
213
214 <para>The <command>login</command>, <command>agetty</command>, and
215 <command>init</command> programs (and others) use a number of log
216 files to record information such as who was logged into the system and
217 when. However, these programs will not write to the log files if they
218 do not already exist. Initialize the log files and give them
219 proper permissions:</para>
220
[586feb7]221<screen><userinput>touch ${CLFS}/var/run/utmp ${CLFS}/var/log/{btmp,lastlog,wtmp}
222chmod -v 664 ${CLFS}/var/run/utmp ${CLFS}/var/log/lastlog</userinput></screen>
[02095ae]223
224 <para>The <filename>/var/run/utmp</filename> file records the users
225 that are currently logged in. The <filename>/var/log/wtmp</filename>
226 file records all logins and logouts. The
227 <filename>/var/log/lastlog</filename> file records when
228 each user last logged in. The <filename>/var/log/btmp</filename> file
229 records the bad login attempts.</para>
230
231</sect1>
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