[02095ae] | 1 | <?xml version="1.0" encoding="ISO-8859-1"?> |
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| 2 | <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN" |
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| 3 | "http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd" [ |
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| 4 | <!ENTITY % general-entities SYSTEM "../general.ent"> |
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| 5 | %general-entities; |
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| 6 | ]> |
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| 7 | |
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| 8 | <sect1 id="ch-final-preps-creatingfiles"> |
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| 9 | <?dbhtml filename="creatingfiles.html"?> |
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| 10 | |
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| 11 | <title>Creating Essential Files</title> |
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| 12 | |
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| 13 | <para>A proper Linux system maintains a list of the mounted file systems in |
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| 14 | the file <filename>/etc/mtab</filename>. Normally, this file would be |
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| 15 | created when we mount a new file system. Since we will not be mounting any |
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| 16 | file systems inside our chroot environment, create an empty file for |
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| 17 | utilities that expect the presence of <filename>/etc/mtab</filename>:</para> |
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| 18 | |
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| 19 | <screen><userinput>touch ${LFS}/etc/mtab</userinput></screen> |
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| 20 | |
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| 21 | <para>In order for user <systemitem class="username">root</systemitem> to be |
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| 22 | able to login and for the name <quote>root</quote> to be recognized, there |
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| 23 | must be relevant entries in the <filename>/etc/passwd</filename> and |
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| 24 | <filename>/etc/group</filename> files.</para> |
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| 25 | |
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| 26 | <para>Create the <filename>/etc/passwd</filename> file by running the following |
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| 27 | command:</para> |
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| 28 | |
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| 29 | <screen><userinput>cat > %{LFS}/etc/passwd << "EOF" |
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| 30 | <literal>root:x:0:0:root:/root:/bin/bash</literal> |
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| 31 | EOF</userinput></screen> |
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| 32 | |
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| 33 | <para>The actual password for <systemitem class="username">root</systemitem> |
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| 34 | (the <quote>x</quote> used here is just a placeholder) will be set later.</para> |
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| 35 | |
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| 36 | <para>Create the <filename>/etc/group</filename> file by running the following |
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| 37 | command:</para> |
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| 38 | |
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| 39 | <screen><userinput>cat > ${LFS}/etc/group << "EOF" |
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| 40 | <literal>root:x:0: |
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| 41 | bin:x:1: |
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| 42 | sys:x:2: |
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| 43 | kmem:x:3: |
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| 44 | tty:x:4: |
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| 45 | tape:x:5: |
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| 46 | daemon:x:6: |
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| 47 | floppy:x:7: |
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| 48 | disk:x:8: |
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| 49 | lp:x:9: |
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| 50 | dialout:x:10: |
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| 51 | audio:x:11: |
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| 52 | video:x:12: |
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| 53 | utmp:x:13: |
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| 54 | usb:x:14: |
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| 55 | cdrom:x:15:</literal> |
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| 56 | EOF</userinput></screen> |
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| 57 | |
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| 58 | <para>The created groups are not part of any standard—they are groups |
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| 59 | decided on in part by the requirements of the Udev configuration in this |
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| 60 | chapter, and in part by common convention employed by a number of existing |
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| 61 | Linux distributions. The Linux Standard Base (LSB, available at <ulink |
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| 62 | url="http://www.linuxbase.org"/>) recommends only that, besides the group |
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| 63 | <systemitem class="groupname">root</systemitem> with a Group ID (GID) of 0, |
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| 64 | a group <systemitem class="groupname">bin</systemitem> with a GID of 1 be |
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| 65 | present. All other group names and GIDs can be chosen freely by the system |
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| 66 | administrator since well-written programs do not depend on GID numbers, but |
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| 67 | rather use the group's name.</para> |
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| 68 | |
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| 69 | <para>The <command>login</command>, <command>agetty</command>, and |
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| 70 | <command>init</command> programs (and others) use a number of log |
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| 71 | files to record information such as who was logged into the system and |
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| 72 | when. However, these programs will not write to the log files if they |
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| 73 | do not already exist. Initialize the log files and give them |
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| 74 | proper permissions:</para> |
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| 75 | |
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| 76 | <screen><userinput>touch ${LFS}/var/run/utmp ${LFS}/var/log/{btmp,lastlog,wtmp} |
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| 77 | chgrp -v utmp ${LFS}/var/run/utmp ${LFS}/var/log/lastlog |
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| 78 | chmod -v 664 ${LFS}/var/run/utmp ${LFS}/var/log/lastlog</userinput></screen> |
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| 79 | |
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| 80 | <para>The <filename>/var/run/utmp</filename> file records the users |
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| 81 | that are currently logged in. The <filename>/var/log/wtmp</filename> |
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| 82 | file records all logins and logouts. The |
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| 83 | <filename>/var/log/lastlog</filename> file records when |
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| 84 | each user last logged in. The <filename>/var/log/btmp</filename> file |
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| 85 | records the bad login attempts.</para> |
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| 86 | |
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| 87 | </sect1> |
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