Merge pull request #43 from paulcobbaut/master

update

Author: Paul Cobbaut

books/minibook_boot_management/config

@@ -10,3 +10,4 @@ BOOKTITLE="boot management"
 # define book as directories in certain order
 add_mod chapter bootloader
 add_mod chapter init
+add_mod chapter systemd

books/minibook_shell/config

@@ -9,7 +9,6 @@ BOOKTITLE="shell expansion"
 
 # define book as directories in certain order
 
-#add_mod chapter shell_introduction
 add_mod chapter shell_arguments
 add_mod chapter shell_control_operators
 add_mod chapter shell_variables

images/systemd_diagram.png

@@ -102,8 +102,9 @@
 </tgroup>
 </table>
 </section>
-<section><title>undo and repeat (u .)</title>
-	<para>When in command mode, you can undo your mistakes with u. You can do your mistakes twice with . (in other words, the . will repeat your last command).</para>
+<section><title>undo, redo and repeat (u .)</title>
+	<para>When in command mode, you can undo your mistakes with u. Use <command>ctrl-r</command> to redo the undo.</para>
+	<para>You can do your mistakes twice with . (in other words, the . will repeat your last command).</para>
 <table frame='all'><title>undo and repeat</title>
 <?dbfo table-width="80%" ?>
 <tgroup cols='2' align='center' colsep='1' rowsep='1'>
@@ -120,6 +121,10 @@
   <entry>u</entry>
   <entry>undo the last action</entry>
 </row>
+<row>
+  <entry>ctrl-r</entry>
+  <entry>redo the last undo</entry>
+</row>
 <row>
   <entry>.</entry>
   <entry>repeat the last action</entry>

modules/intro_vi/030_vi_theory.xml

@@ -6,11 +6,11 @@ set -C</screen>
 	<para>2. Verify that <command>noclobber</command> is active by repeating an <command>ls</command> on <command>/etc/</command> with redirected output to a file.</para>
 	<screen>ls /etc &#062; etc.txt 
 ls /etc &#062; etc.txt (should not work)</screen>
-	<para>4. When listing all shell options, which character represents the <command>noclobber</command> option ?</para>
+	<para>3. When listing all shell options, which character represents the <command>noclobber</command> option ?</para>
 	<screen>echo $- (noclobber is visible as C)</screen>
-	<para>5. Deactivate the <command>noclobber</command> option.</para>
+	<para>4. Deactivate the <command>noclobber</command> option.</para>
 	<screen>set +o noclobber</screen>
-	<para>6. Make sure you have two shells open on the same computer. Create an empty <command>tailing.txt</command> file. Then type <command>tail -f tailing.txt</command>. Use the second shell to <command>append</command> a line of text to that file. Verify that the first shell displays this line.</para>
+	<para>5. Make sure you have two shells open on the same computer. Create an empty <command>tailing.txt</command> file. Then type <command>tail -f tailing.txt</command>. Use the second shell to <command>append</command> a line of text to that file. Verify that the first shell displays this line.</para>
 	<screen>paul@deb503:~$ &#062; tailing.txt
 paul@deb503:~$ tail -f tailing.txt 
 hello
@@ -19,7 +19,7 @@ world
 in the other shell:
 paul@deb503:~$ echo hello >> tailing.txt 
 paul@deb503:~$ echo world >> tailing.txt</screen>
-	<para>7. Create a file that contains the names of five people. Use <command>cat</command> and output redirection to create the file and use a <command>here document</command> to end the input.</para>
+	<para>6. Create a file that contains the names of five people. Use <command>cat</command> and output redirection to create the file and use a <command>here document</command> to end the input.</para>
 	<screen>paul@deb503:~$ cat &#062; tennis.txt &#060;&#060; ace
 > Justine Henin
 > Venus Williams

modules/ioredirection/050_ioredirection_solution.xml

@@ -1,7 +1,7 @@
 <?hard-pagebreak?>
 <section><title>about the Linux kernel</title>
 	<section><title>kernel versions</title>
-		<para>In 1991 Linux Torvalds wrote (the first version of) the Linux kernel. He put it online, and other people started contributing code. Over 4000 individuals contributed source code to the latest kernel release (version 2.6.27 in November 2008).</para>
+		<para>In 1991 Linus Torvalds wrote (the first version of) the Linux kernel. He put it online, and other people started contributing code. Over 4000 individuals contributed source code to the latest kernel release (version 2.6.27 in November 2008).</para>
 		<para>Major Linux kernel versions used to come in even and odd numbers. Versions <command>2.0</command>, <command>2.2</command>, <command>2.4</command> and <command>2.6</command> are considered stable kernel versions. Whereas <command>2.1</command>, <command>2.3</command> and <command>2.5</command> were unstable (read development) versions. Since the release of 2.6.0 in January 2004, all development has been done in the 2.6 tree. There is currently no v2.7.x and according to Linus the even/stable vs odd/development scheme is abandoned forever.</para>
 	</section>
 	<section><title>uname -r</title>

modules/kernel/031_linux_kernel.xml

@@ -180,7 +180,7 @@ root@rhel65:/etc#</screen>
 	</section>
 <?hard-pagebreak?>
 	<section><title>logger</title>
-		<para>The logger command can be used to generate syslog test messages. You can aslo use it in scripts. An example of testing syslogd with the <command>logger</command><indexterm><primary>logger(1)</primary></indexterm> tool.</para>
+		<para>The logger command can be used to generate syslog test messages. You can also use it in scripts. An example of testing syslogd with the <command>logger</command><indexterm><primary>logger(1)</primary></indexterm> tool.</para>
 		<screen>[root@rhel4a ~]# logger -p local4.debug "l4 debug"
 [root@rhel4a ~]# logger -p local4.crit "l4 crit"
 [root@rhel4a ~]# logger -p local4.emerg "l4 emerg"

modules/logging/030_logging_theory.xml

@@ -173,6 +173,29 @@ laika.local        => ik-in-f83.google.com          0b      0b     39b
 <screen>[root@centos65 ~]# iptraf 
 [root@centos65 ~]# iptraf -i eth0</screen>
 	</section>
+	<section><title>nload</title>
+	<para><command>nload</command> displays current network traffic in the command line. Use the arrow keys to walk through devices.</para>
+	<screen>Device wlan0 [192.168.1.35] (2/2):
+==============================================================================================
+Incoming:
+
+
+                                       ||
+ ..                                    ##  ||        ..     Curr: 13.20 kBit/s
+ ##                                    ##  ##..      ##     Avg: 656.33 kBit/s
+ ##..                                  ##||####      ##     Min: 0.00 Bit/s
+ ####                                  ##########    ##..   Max: 4.44 MBit/s
+.####                                ..##########  ..####   Ttl: 895.44 MByte
+Outgoing:
+
+
+
+                                                            Curr: 11.84 kBit/s
+                                                            Avg: 105.90 kBit/s
+                                                            Min: 0.00 Bit/s
+                                                            Max: 518.48 kBit/s
+ ..                                  ............    ..     Ttl: 672.49 MByte</screen>
+	</section>
 <?hard-pagebreak?>
 	<section><title>nmon</title>
 	<para>Another popular and all round tool is <command>nmon</command>.</para>

modules/monitoring/030_monitoring_theory.xml

@@ -1 +1,2 @@
-<para>The shell is also responsible for <command>file globbing</command><indexterm><primary>file globbing</primary></indexterm> (or dynamic filename generation). This chapter will explain <command>file globbing</command>.</para>
+<para>Typing <command>man 7 glob</command> (on Debian) will tell you that long ago there was a program called <command>/etc/glob</command> that would expand wildcard patterns.</para>
+<para>Today the shell is responsible for <command>file globbing</command><indexterm><primary>file globbing</primary></indexterm> (or dynamic filename generation). This chapter will explain <command>file globbing</command>.</para>

modules/shell_globbing/020_shell_file_globbing_about.xml

@@ -19,7 +19,7 @@
 <?hard-pagebreak?>
 		<section><title>block device</title>
 			<para>Random access hard disk devices have an abstraction layer called <command>block device</command><indexterm><primary>block device</primary></indexterm> to enable formatting in fixed-size (usually 512 bytes) blocks. Blocks can be accessed independent of access to other blocks.</para>
-	<screen>[root@centos65 ~]# lsblk
+	<screen>[root@centos65 ~]# <command>lsblk</command>
 NAME                        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
 sda                           8:0    0   40G  0 disk 
 --sda1                        8:1    0  500M  0 part /boot
@@ -35,9 +35,30 @@ brw-rw----. 1 root disk 8,  1 Apr 19 10:12 /dev/sda1
 brw-rw----. 1 root disk 8,  2 Apr 19 10:12 /dev/sda2
 brw-rw----. 1 root disk 8, 16 Apr 19 10:12 /dev/sdb
 brw-rw----. 1 root disk 8, 32 Apr 19 10:12 /dev/sdc</screen>
+	<para>Virtual devices like <command>raid</command> or <command>lvm</command> are also listed as <command>block devices</command> as seen in this RHEL7 virtual machine.</para>
+	<screen>[root@centos7 ~]# <command>lsblk</command>
+NAME                    MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
+sda                       8:0    0     8G  0 disk
+├─sda1                    8:1    0   400M  0 part
+│ └─md0                   9:0    0 399.7M  0 raid1
+├─sda2                    8:2    0   400M  0 part
+│ └─md0                   9:0    0 399.7M  0 raid1
+└─sda3                    8:3    0   400M  0 part
+sdb                       8:16   0     8G  0 disk
+sdc                       8:32   0     8G  0 disk
+sdd                       8:48   0     2G  0 disk
+sde                       8:64   0     2G  0 disk
+sdf                       8:80   0  20.5G  0 disk
+├─sdf1                    8:81   0   500M  0 part  /boot
+└─sdf2                    8:82   0    20G  0 part
+  ├─centos_centos7-swap 253:0    0     2G  0 lvm   [SWAP]
+  └─centos_centos7-root 253:1    0    18G  0 lvm   /
+sr0                      11:0    1  1024M  0 rom
+[root@centos7 ~]#</screen>
 			<para>Note that a <command>character device</command><indexterm><primary>character device</primary></indexterm> is a constant stream of characters, being denoted by a c in <command>ls -l</command>. Note also that the <command>ISO 9660</command> standard for cdrom uses a <command>2048 byte</command> block size.</para>
 			<para>Old hard disks (and floppy disks) use <command>cylinder-head-sector</command><indexterm><primary>CHS</primary></indexterm> addressing to access a sector on the disk. Most current disks use <command>LBA (Logical Block Addressing)</command><indexterm><primary>LBA</primary></indexterm>.</para>
 		</section>	
+<?hard-pagebreak?>
 		<section><title>solid state drive</title>
 			<para>A <command>solid state drive</command><indexterm><primary>solid state drive</primary></indexterm> or <command>ssd</command><indexterm><primary>ssd</primary></indexterm> is a block device without moving parts. It is comparable to <command>flash memory</command>. An <command>ssd</command> is more expensive than a hard disk, but it typically has a much faster access time.</para>
 			<para>In this book we will use the following pictograms for <command>spindle disks</command> (in brown) and <command>solid state disks</command> (in blue).</para>

modules/storage_devices/030_diskdevices_theory.xml

@@ -1,7 +1,7 @@
 <?hard-pagebreak?>
 <section><title>practice: mounting file systems</title>
 	<para>1. Mount the small 200MB partition on /home/project22.</para>
-	<para>2. Mount the big 400MB primary partition on /mnt, the copy some files to it (everything in /etc). Then umount, and mount the file system as read only on /srv/nfs/salesnumbers. Where are the files you copied ?</para>
+	<para>2. Mount the big 400MB primary partition on /mnt, then copy some files to it (everything in /etc). Then umount, and mount the file system as read only on /srv/nfs/salesnumbers. Where are the files you copied ?</para>
 	<para>3. Verify your work with <command>fdisk</command>, <command>df</command> and <command>mount</command>. Also look in <command>/etc/mtab</command> and <command>/proc/mounts</command>.</para>
 	<para>4. Make both mounts permanent, test that it works.</para>
 	<para>5. What happens when you mount a file system on a directory that contains some files ?</para>

modules/storage_mounting/040_mounting_practice.xml

@@ -3,7 +3,7 @@
 	<para>1. Mount the small 200MB partition on /home/project22.</para>
 	<screen>mkdir /home/project22
 mount /dev/sdc1 /home/project22</screen>
-	<para>2. Mount the big 400MB primary partition on /mnt, the copy some files to it (everything in /etc). Then umount, and mount the file system as read only on /srv/nfs/salesnumbers. Where are the files you copied ?</para>
+	<para>2. Mount the big 400MB primary partition on /mnt, then copy some files to it (everything in /etc). Then umount, and mount the file system as read only on /srv/nfs/salesnumbers. Where are the files you copied ?</para>
 	<screen>mount /dev/sdb1 /mnt
 cp -r /etc /mnt
 ls -l /mnt</screen>

modules/storage_mounting/050_mounting_solution.xml

@@ -0,0 +1 @@
+<title>systemd</title>

modules/systemd/010_systemd_title.xml

@@ -0,0 +1,3 @@
+<para>Many Unix and Linux distributions have been using <command>init</command> scripts to start daemons in the same way that <command>Unix System V</command><indexterm><primary>System V</primary></indexterm> did back in 1983.</para>
+<para>Starting 2015 this is considered legacy. Most Linux distributions, including Debian and Red Hat/CentOS, are in the process of migrating to <command>systemd</command>. They will however remain compatible with <command>init</command> because it will take many years before all applications are migrated.</para>
+<para>This chapter explains how to manage Linux with <command>systemd</command>.</para>