[673b0d8] | 1 | <?xml version="1.0" encoding="ISO-8859-1"?>
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[1770019] | 2 | <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN" "http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd" [
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[673b0d8] | 3 | <!ENTITY % general-entities SYSTEM "../general.ent">
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| 4 | %general-entities;
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| 5 | ]>
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| 6 | <sect1 id="ch-system-pwdgroup">
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[bce08ef] | 7 | <title>Creating the passwd, group, and log Files</title>
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[673b0d8] | 8 | <?dbhtml filename="pwdgroup.html"?>
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| 9 |
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[81fd230] | 10 | <indexterm zone="ch-system-pwdgroup"><primary sortas="e-/etc/passwd">/etc/passwd</primary></indexterm>
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| 11 | <indexterm zone="ch-system-pwdgroup"><primary sortas="e-/etc/group">/etc/group</primary></indexterm>
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| 12 | <indexterm zone="ch-system-pwdgroup"><primary sortas="e-/var/run/utmp">/var/run/utmp</primary></indexterm>
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| 13 | <indexterm zone="ch-system-pwdgroup"><primary sortas="e-/var/log/btmp">/var/log/btmp</primary></indexterm>
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| 14 | <indexterm zone="ch-system-pwdgroup"><primary sortas="e-/var/log/lastlog">/var/log/lastlog</primary></indexterm>
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| 15 | <indexterm zone="ch-system-pwdgroup"><primary sortas="e-/var/log/wtmp">/var/log/wtmp</primary></indexterm>
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| 16 |
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| 17 | <para>In order for user <emphasis>root</emphasis> to be able to login
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[bc2136e] | 18 | and for the name <quote>root</quote> to be recognized, there must be relevant
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| 19 | entries in the <filename>/etc/passwd</filename> and
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[81fd230] | 20 | <filename>/etc/group</filename> files.</para>
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| 21 |
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| 22 | <para>Create the <filename>/etc/passwd</filename> file by running the following
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| 23 | command:</para>
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[673b0d8] | 24 |
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[8ad7980] | 25 | <screen><userinput>cat > /etc/passwd << "EOF"
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[e2c85b1] | 26 | <literal>root:x:0:0:root:/root:/bin/bash</literal>
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[8ad7980] | 27 | EOF</userinput></screen>
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[673b0d8] | 28 |
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[81fd230] | 29 | <para>The actual password for <emphasis>root</emphasis> (the <quote>x</quote>
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| 30 | used here is just a placeholder) will be set later.</para>
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| 31 |
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[cad7b50] | 32 | <para>Create the <filename>/etc/group</filename> file by running the following
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[81fd230] | 33 | command:</para>
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[673b0d8] | 34 |
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[8ad7980] | 35 | <screen><userinput>cat > /etc/group << "EOF"
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[d72e04a] | 36 | <literal>root:x:0:
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[e2c85b1] | 37 | bin:x:1:
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| 38 | sys:x:2:
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[673b0d8] | 39 | kmem:x:3:
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[e2c85b1] | 40 | tty:x:4:
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| 41 | tape:x:5:
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| 42 | daemon:x:6:
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| 43 | floppy:x:7:
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| 44 | disk:x:8:
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| 45 | lp:x:9:
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| 46 | dialout:x:10:
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| 47 | audio:x:11:
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| 48 | video:x:12:
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| 49 | utmp:x:13:
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[3da377d] | 50 | usb:x:14:
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| 51 | cdrom:x:15:</literal>
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[8ad7980] | 52 | EOF</userinput></screen>
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[673b0d8] | 53 |
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[d001e2b] | 54 | <para>The created groups are not part of any standard—they are groups
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[be7082f] | 55 | decided on in part by the requirements of the Udev configuration in this
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[b2812fc] | 56 | chapter, and in part by common convention employed by a number of existing Linux
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[d001e2b] | 57 | distributions. The Linux Standard Base (LSB, available at <ulink
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| 58 | url="http://www.linuxbase.org"/>) recommends only that, besides the group
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| 59 | <quote>root</quote> with a Group ID (GID) of 0, a group <quote>bin</quote> with
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| 60 | a GID of 1 be present. All other group names and GIDs can be chosen freely by
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| 61 | the system administrator since well-written programs do not depend on GID
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| 62 | numbers, but rather use the group's name.</para>
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[81fd230] | 63 |
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| 64 | <para>To remove the <quote>I have no name!</quote> prompt, start a new
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| 65 | shell. Since a full Glibc was installed in <xref
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| 66 | linkend="chapter-temporary-tools"/> and the
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| 67 | <filename>/etc/passwd</filename> and <filename>/etc/group</filename>
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| 68 | files have been created, user name and group name resolution will now
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| 69 | work.</para>
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[673b0d8] | 70 |
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[cad7b50] | 71 | <screen role="nodump"><userinput>exec /tools/bin/bash --login +h</userinput></screen>
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[673b0d8] | 72 |
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[bc2136e] | 73 | <para>Note the use of the <parameter>+h</parameter> directive. This tells
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| 74 | <command>bash</command> not to use its internal path hashing. Without this
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| 75 | directive, <command>bash</command> would remember the paths to binaries it has
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[7678532] | 76 | executed. To ensure the use of the newly compiled binaries as soon as they are
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[bc2136e] | 77 | installed, the <parameter>+h</parameter> directive will be used for the duration
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| 78 | of this chapter.</para>
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[81fd230] | 79 |
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| 80 | <para>The <command>login</command>, <command>agetty</command>, and
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| 81 | <command>init</command> programs (and others) use a number of log
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| 82 | files to record information such as who was logged into the system and
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| 83 | when. However, these programs will not write to the log files if they
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[cad7b50] | 84 | do not already exist. Initialize the log files and give them
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[81fd230] | 85 | proper permissions:</para>
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[673b0d8] | 86 |
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| 87 | <screen><userinput>touch /var/run/utmp /var/log/{btmp,lastlog,wtmp}
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[5998892] | 88 | chgrp -v utmp /var/run/utmp /var/log/lastlog
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| 89 | chmod -v 664 /var/run/utmp /var/log/lastlog</userinput></screen>
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[673b0d8] | 90 |
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[81fd230] | 91 | <para>The <filename>/var/run/utmp</filename> file records the users
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| 92 | that are currently logged in. The <filename>/var/log/wtmp</filename>
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| 93 | file records all logins and logouts. The
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| 94 | <filename>/var/log/lastlog</filename> file records when
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| 95 | each user last logged in. The <filename>/var/log/btmp</filename> file
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| 96 | records the bad login attempts.</para>
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| 97 |
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[673b0d8] | 98 | </sect1>
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[81fd230] | 99 |
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