Numbers and Symbols
- / filesystem, 200
- 128-bit message digests, 60
A
- acceleration, linear, input devices, 107
- AccelerationProfile, input devices, 107
- accessibility
- GRUB beep for input, 116
- key presses, 119
- legacy utilities, 111
- Orca, 112
- screen magnifier, 116
- speech recognition, KDE, 114
- Ubuntu, 209
- account information, 178
- accounts
- addresses
- IPv6, 161, 170
- local, IPv6 pings, 165
- private, internal use, 160
- administrative tasks, 124–138, 257–263
- aliased commands, 90
- aliases, missing, 98
- anacron, 129
- Apache, /var/log/httpd/access.log, 53
- appending files, 61
- applications, containerization versus virtualization, 35
- apt-cache, Debian, package lists, 38
- architecture, system, –20, 220–226
- ARP, disabling, 170
- arp, IP address-to-Mac address pair, 168
- arrays, Bash script, 91
- assistive technology, 110, 115–116
- at
- atq, as root, 210
- authentication
- autofs, configuration files, default, 72
B
- backups, 205
- Bash, 54
- bash function, 97
- command history, 53
- command substitution, 93
- configuration files, locating on login, 88
- environment settings, 47
- executing commands, 87
- file overwrite, preventing, 47
- if conditionals, 88
- initialization files, no reading, 91
- logout, command execution, 87
- output, redirect, 47
- printing, list of numbers, 88
- quotes, 57
- reading commands, 87
- sayHello function, 209
- scripts, command-line parameters, 88
- shell script, outputting name, 55
- source built-in, 100
- STDERR, redirecting, 52
- STDOUT, redirecting, 52
- umask setting, 79
- Bash scripts
- arrays, creating, 91
- debugging, #! line, 96
- division operator, 98
- email, sending, 98
- exit code, 95
- find command, 96
- functions, command sequence as, 89
- greater than or equal to, 94
- initialization, system wide, 94
- keywords, 89, 95
- loops, 100
- output, 96
- return values, testing, 95
- terminating, 99
- values, user entry, 96
- variables, 95, 98, 208
- Bash shell
- invocation, file execution, 95
- path, /srv/bin, 95
- /user/local/lib, 28
- /usr/local/bin, 100
- .bash_history, 201
- .bashrc, 201
- BIOS (basic input/output system)
- boot loader, disk location, 200
- integrated peripherals, 20
- blocks, reserving, 77
- boot loaders, ISO9660 CD-ROMS, 14
- boot order, 14
- /boot partition
- /dev/sdal, 33
- extlinux, 33
- booting
- configuration, /etc/default/grub, 29
- GUI, disabling, 105
- initramfs, 14
- No init found, 14
- reboot,
- troubleshooting, kernel ring buffer and,
- bootstrapping, 205
- Braille display, 107
- btrfs subvolume, 75–76
- built-in commands, listing read-only variables, 91
- bunzip2, 61
- bzip2, archive, sending to STDOUT, 56
C
- case statement, 92–93
- CentOS
- groups, deleting, 217
- packages, 37, 39
- CentOS 6, RAM disk creation, 12
- change, password changes, 191
- character maps, 217
- character sets, 125
- characters
- commands as function, Bash script, 89
- multibyte representation, 126
- sequence, alternate command, 89
- child processes, variables, 208
- chmod
- execute permission, 97
- minimum privileges, 90
- chown, recursive change, 71
- Chrony package, 152
- chronyd, status, 156
- CIDR (Classless Inter-Domain Routing), subnets
- clock, hardware, 143
- command-line
- date, 143
- parameters, Bash script, 88
- commands. See also specific commands
- aliased, removing, 90
- executing two, 89
- foreground processing, 50
- history, 53
- libraries, 29
- locating elements, 69
- paths, 61
- return value test, 97
- scheduling execution, 125
- types, 57
- compression, 59
- decompressing files, 53
- log files, disabling, 149
- configuration
- booting, 29
- CUPS, 142
- devices, udev,
- /etc/hosts, 164
- Ethernet devices, 173
- files
- autofs, 72
- Bash, 86
- Chrony, 152
- locating on login, Bash, 88
- logrotate, 156
- modprobe, 196
- priority order, 72
- systemd, , 72
- Upstart,
- X clients, 107
- XDMCP, 118
- yum, 36
- GRUB 2, 26, 201
- IPv6, 166
- kernel, 13
- LightDM, 105, 111, 216
- modprobe, 196
- persistent, 157–174, 270–277
- SSH custom client, 189
- systemd, 13, 15
- udev,
- UEFI (Unified Extensible Firmware Interface), 15
- Weston, 115
- Wi-Fi devices, 173
- X, 107, 112, 113
- connectivity
- testing, TCP level, 170
- troubleshooting, 167
- copying
- directories, recursive, 49
- files, at user creation, 90
- copy-on-write, 73
- cp, 202
- confirmation, 100
- directories, copying recursively, 49
- file overwrite, 49
- cpio, 56
- CPU time, displaying, 180
- cron, 124
- crontab, 210
- other users, 211
- removing, 136
- CUPS (Common UNIX Printing System)
- configuration files, 142
- daemon, listening on port 631, 150
- default local printer configuration, 155
- default port, 145
- print jobs, completed, viewing, 146
- print sharing, 149
- restarting, 149
- currency-related localization, 132
- cut, delimiters, default, 50
D
- data, writing to disk, 74
- databases
- hosts, enumerating, 163
- updates, 71
- date
- command line, 143
- current, 125
- environment variables, 126
- setting, 153
- date, date/time set, 153
- DATE variable, shell script, 92
- dbus, communication, monitoring, 197
- D-Bus, machine ID, 38
- Debian
- packages, 30–32, 33, 36, 38, 198–199
- reconfiguration, 31
- services, starting/stopping, 185
- source repository, 198
- startup scripts, 20
- time zones, 133, 216
- updates, 27
- zsh package, 28
- debugfs, 74
- debugging
- /etc/resolv.conf and, 172
- messages, journalctl, 149
- slapd, 132
- XFS filesystem, 78
- declare, 91, 93
- decompressing files, 53, 60
- default gateway, changing, 164
- desktop, 113, 251–257
- devices, 63–81
- answers to review questions, 239–245
- drivers, lsmod output, 11
- empty, 78
- filters, vgscan, 39
- hotplug, udevadm commands,
- input, acceleration, 107
- NVMe-based, 18
- USB, listing,
- wireless, parameters, 168
- /dev/sdal, /boot partition, 33
- df, 79, 204
- DHCP, activity, 171
- dig, 162, 172, 173
- directories
- backups, user home, 37
- changes, tilde character and environment variable, 92
- copying recursively, 49
- FHS, local binaries, 99
- files, coping, 209
- finding, 48
- ldconfig, command-line, 38
- printing, 54, 199
- removing, 48
- root user, home directory, 27
- skeleton home directory, 136
- system log, 155
- time zones, 217
- useradd, 128
- users, changing, 130
- display
- accessibility, Orca, 112
- assistive technology, 110
- Braille, 107, 116
- fonts, 107, 110
- fonts.scale, 112
- GDM (GNOME Display Manager), welcome message, 105
- GNOME, 106, 108, 109, 114
- GUI, boot disable, 105
- inactivity timeout, 113
- input devices, linear acceleration, 107
- KDE, magnification, 108
- LightDM, 105, 106, 110
- monitor, 105, 106
- mouse gestures, 108
- RDP (Remote Desktop), server-side implementation, 114
- screen magnifier, 116
- video cards, RAM, 112
- X
- authority files, 108
- local client, 111
- monitor vertical refresh, 107
- window information, 109
- X Display Manager, login, 116
- X session
- information, 115
- pointer keys, 114
- terminal device width, 111
- xauth authority file, 110
- XFree86, hardware query, 106
- xfwm4 window manager, 113
- xorg.conf
- blank mode, 109
- video mode changes, 108
- division operator, Bash script, 98
- dmesg, time, 196
- DNS (Domain Name System)
- default route, 160
- lookups, overriding, 166
- POP3 server specification, 173
- setting, 163
- SPF query, 167
- systemd-resolved, 173
- documentation, access, 47
- domain names, 162
- DPMS (Display Power Management Signaling), 109, 113
- drift file, location, 144
- driftfile, 217
- du, printing, 205
- dumpe2fs, partition bad blocks, 73
E
- e2fsck, superblocks, location, 79
- egrep, 52
- email. See also messages
- abuse account, 146
- aliases, 210
- forwarding, Procmail, 150
- per-user forwarding, 153
- processing statistics, 149
- removing, 150
- root user, 144, 209
- emulation, ping, 166
- encrypted files, gpg, 187
- encryption
- passwords, 131
- remote desktop, 113
- env, 96
- environment, Bash, 47
- environment variables
- date format, 126
- declaring, 55
- directory change, tilde character and, 92
- localization, 127
- paper size, 135
- PS1, 87
- removing, 87
- removing temporarily, 57
- single-line viewing, 99
- terminal device, X session, 111
- text editors, 58
- time format, 126
- usernames, 99
- ESP (EFI system partition)
- filesystem mount, 26
- format type, 33
- grub-install, 38
- /etc/aliases, email messages, 150
- /etc/default/grub, 29, 32
- /etc/fstab, 72, 75, 81
- /etc/hosts, 164, 171
- /etc/hosts.allow, wildcards, 186
- /etc/inetd.conf, services, disabling, 184
- /etc/inittab, runlevel, single-user mode, 185
- /etc/localtime, directory listings, 151
- /etc/logrotate.conf, emailing log, 144
- /etc/ntp.conf, drift file, location, 144
- /etc/passwd, 49
- /etc/resolv.conf, debugging and, 172
- /etc/security/limits.conf, 182
- /etc/shadow, 183, 188
- /etc/sudoers, 214
- admins group, 190
- editing, 182
- password prompt, 180
- /etc/X11/xorg.conf, 105
- /etc/yum.conf, kernel update, 32
- Ethernet, device configuration, 173
- event viewing,
- Exam 1, practice exam, 284–288
- Exam 101-500, practice exam, 288–292
- executable files, location, 67
- exFAT filesystem, formatting, 78
- Exim server
- mail delivery, 155
- SMTP traffic and, 148
- expiration, removing, 124
- export
- names as functions, 94
- variables, 101
- expressions, regular expressions, 59
- ext2 filesystem, 68
- journal, adding, 76
- superblock, corrupt, 79
- ext3 filesystem, 68
- checking clean, 75
- metadata image, 204
- repairs, 204
- extlinux, installation, /boot partition, 33
F
- FAT (File Allocation Table)
- formatting, 76
- rescue disks, boot loader, 13
- Fedora 22, packages, installation, 37
- fgrep, 59
- FHS (filesystem hierarchy standard), 69–70, 99
- Fibre Channel, 17
- file compression, 53, 59, 60
- file dumps, maximum file size, 75
- file tests, 95
- $FILEPATH variable, 92
- files
- appending, 61
- binary mode, 58
- content search, 203
- copying, 90, 209
- decompressing, 53
- existence, testing, 93
- extracting, 50
- group information, 126
- gzip, 50
- initialization, no reading, 91
- line numbers, prepending, 53
- listing, 56
- moving, 54
- open, listing, 186
- overwriting, confirmation, 100
- ownership, 68, 204
- passwords, 125
- removing, 55
- removing lines, 60
- searches, backward, 55
- size, 55, 190
- splitting, 60
- tar, 50
- UID, 125
- usernames, 125
- users, deleted, 79
- filesystems
- copy-on-write, 73
- creating, bad blocks, 204
- disk space, 70
- ext2, 68
- ext3, 68
- extensions, missing, 49
- hierarchy, 63–81, 239–245
- information, 70
- inodes, 68
- ISO, creating, 72
- Linux, 63–81
- listing currently mounted, 34
- mounted, 204
- mounting, 69, 70, 71, 77
- overwriting, 49
- processes, running, 196
- read-write mode, 74
- ro, 73
- sticky bits, 69
- type, mke2fs, 72
- unmounting, 74, 178
- verifying, 74
- xfs_check, 74
- find, 54, 81, 97, 99, 205
- firewalls
- fonts, X.org, 107
- fonts.scale, 112
- for loops, 90, 93
- foreground processing, 50, 51
- fsck, 68, 72, 204
G
- gateways, default, 160, 164
- GDM (GNOME Display Manager)
- greeter, welcome message, 105
- login window options, 118
- welcome message, 105
- getent, password database, 136
- GIDs, UIDs and, 130
- GNOME
- GOK (GNOME On-Screen Keyboard), 109
- high-contrast theme, 108
- on-screen keyboard, 119
- screen reader, 106, 109
- slow keys, 114
- sticky keys, 106
- GNU, commands, 41–61
- answers to review questions, 233–239
- GnuPG
- key pair generation, 183
- private keys, daemon process, 189
- GOK (GNOME On-Screen Keyboard), 109, 111
- gpg
- detached signatures, 188
- encrypted files, 187
- keys, sending to key server, 190
- public keys, 185
- signatures, generating, 183
- GPT disks
- formatting, 77
- partitions, Linux, 37
- greater than or equal to operator, 94
- grep, 100, 174
- group ID, minimum group ID, 137
- group information, 126, 127
- group ownership of files, 68
- groupadd, 135, 137
- groupdel, 131
- groups
- GRUB
- beep for input, 116
- versus GRUB 2, 36
- images, alternate directory, 34
- MBR, SATA disk, 30
- menu display, 25
- operating system, default boot, 32
- parameters, editing, 16
- partitions, 25
- ro option, 29
- single-user mode, 25
- timeout, setting, 28
- GRUB Legacy
- dual-boot option, 27
- hd(0,0), 33
- kernel options, 25
- non-Linux kernel, 26
- GRUB2
- configuration changes, 201
- configuration file, 26
- versus GRUB, 36
- grub-install, 34
- grub-mkconfig, 200
- GUI (graphical user interface)
- applications, screen, 209
- boot disable, 105
- .gz extension, 55
- gzip files, 50
H
- handshakes, three-way, 167
- hardware, clock
- head, 48, 51
- /home/webfiles, 124
- host, 160, 172
- hostname
- hostname, programmatic functions, 171
- hosts
- blocking, TCP wrappers and, 208
- storing, ssh keys, 182
- hosts database, enumerating, 163
- hotplug devices, udevadm commands,
- hwclock, system time, 145
I
- IaaS (Infrastructure as a Service), performance, 36
- ICMP (Internet Control Message Protocol)
- echo requests, 216
- packets, generating, interface, 161
- ports, 164
- requests for IPv6, 170
- iconv, 125
- if conditionals, Bash script, 88
- ifconfig, MTU, network interfaces and, 168
- ifup, 214
- IMAPS (IMAP over SSL), listening port, 174
- indexes, recreating, 130
- init, process IDs, 196
- initialization
- files, no reading, 91
- xinit, 117
- initrd, filesystem, 16
- inodes, 68
- input. See also assistive technology
- devices, acceleration, 107
- installation
- Fedora 22 system, 37
- Linux, 21–39, 226–232
- rpm, 28
- yum package, 27
- zypper, 37
- interfaces, 105–119
- answers to review questions, 251–257
- auto, online, 161
- displaying information, 160
- selecting, 161
- interprocess communication service units, systemd, 188
- ip, 168, 174, 215
- IP addresses, availability, 167
- ip route change, 166
- iproute2, address changes, 173
- IPv4/ IPv6 comparison, 164
- IPv6
- addresses, 161, 170
- configuration, 166
- IPv4comparison, 164
- pings, unique local address, 165
- route traces, 172
- traceroute, 162
- IRQ (interrupt request), assignments, viewing,
- ISO filesystem, creating, 72
- ISO9660 CD-ROMS, boot loader, 14
J
- JAVA_PATH, 201
- job schedulers, 125, 126, 127, 128, 133, 136
- jobs, 56, 61
- journal logs, files, maximum size, 147
- journalctl, 149
- filters, time-based, 154
- journal data location, 155
- journal data size, 153
- kernel message queries, 152
- logs, clearing, 150
- maximum space, 154
- new log entries, 147
- service names, 153
- journald.conf, file size, 147
K
- KDE
- magnification, 108
- speech recognition, 114
- keepalive messages, 190
- kernel
- configuration information, 13
- messages, 142, 152
- modules, listing,
- printing information, 47
- ring buffer, ,
- symbols, files, 12
- udev events,
- updating, 32
- key pairs, 179, 183
- keyboard, 209
- keys, listing current, 181
- keywords, Bash scripts, 89, 95
- kill, 20, 51, 52, 57
- killing processes, 54
- klogd, logging messages, 145
L
- LANG variable, 128
- last, recent login details, 184
- LDAP (Lightweight Directory Access Protocol), 213
- entries, importing, 124
- LDIF file, creating, 127
- local files, lookups, 162
- over SSL, listening, 133
- user list, 127
- LDAP over SSL, port, 166
- ldconfig
- cache location, 198
- directories, 35, 38
- library path, directories, 35
- LDIF files, creating, 127
- libraries
- availability, 81
- commands, 29
- printing, 199
- shared, 26
- storage, 30
- libwrap, 191
- LightDM
- lightdm.conf, SeatDefaults section, 117
- line numbering, 201
- linear acceleration, input devices, 107
- link status, displaying, 168
- links, symbolic, 79
- Linux
- / filesystem, 200
- /boot partition, size, 30
- directory structure, 27
- documentation, access, 47
- filesystems, 63–81, 239–245
- GIDs, versus UIDs, 130
- initialization, single-user mode,
- installation, 21–39, 226–232
- package management, 21–39, 226–232
- partition, non-swap, 67
- partition structure, 27
- swap, 30
- swap space, deactivating, 76
- system logs, 155
- time zones, 124, 143
- UIDs, versus GIDs, 130
- ln, symlinks, 69
- load average
- determining, 51
- uptime, 203
- loading, modules,
- locale
- currency-related, 132
- LANG variable, 128
- reconfiguring variables, 128
- locale, 134
- localhost, redirecting to, 166
- locate, 71, 80
- log files
- compression, disabling, 149
- entries, parsing, 211
- journal logs, maximum size, 147
- journalctl, 150
- rotation, configuring, 148
- systemd, disk space used, 144
- log in
- automatic, LightDM, 111
- message display, 18, 19
- number logged, 191
- number of, 182
- password-based, 128
- preventing temporarily, 178
- users logged in, 180
- X Display Manager, 116
- log zeroing, 77
- logging
- kernel messages, 142
- messages, klogd, 145
- logical volumes, 18
- login name, changing, 189
- logout, command execution, Bash shell, 87
- logrotate, 142, 149, 156, 212
- logs, emailing, /etc/logrotate.conf, 144
- lookups, 162
- loops, 90, 100, 101
- ls, 48, 87
- ls -la, output, 67
- lsblk
- empty devices, 78
- filesysem UUID, 80
- partitions, 200
- lsof, instances, open, 215
- lspci, , 12
- LUN (logical unit number), 17
- lvchange, logical volume availability, 35
- LVM (Logical Volume Manager), 30, 31, 32, 34, 35
- .lzma extension, 53
M
- MAC (Media Access Control), 168
- mail, 153, 155
- mail servers, querying for, 161
- man, 52
- man pages, 56, 59
- MBR partitioning system, 26, 30
- MBR-formatted disks, partition size, 77
- measurement, environment variables, 127
- /media/ mount point, 78
- memory
- menu.lst, 29
- messages. See also email
- all users,
- debugging, journalctl, 149
- keepalive, 190
- log, klogd, 145
- Postfix server, 146, 150
- subject, 153
- MIME types, 134
- minimum group ID, 137
- mke2fs, 72, 204
- mkfs.ext4, block reservation, 77
- mkswap, back block check, 80
- modprobe
- configuration information, 196
- module dependencies,
- modules, blacklist information, 12
- monitors, 105, 106
- mount, 69, 73
- mount points, 38
- FHS, removable media, 70
- maximum, 73
- /media/, 78
- mounting
- filesystems, 69, 70, 71, 77
- partitions and, 67, 76
- simulating mount process, 73
- unmounting, 74, 178
- USB disk, 67
- mouse gestures, 108
- moving, files, 54
- MTU, network interfaces, 168
- mv, file overwrite, 49
N
- nagios, monitoring, 50
- name resolution, 168, 186, 213
- netcat, servers, listening ports, 165
- netlink, messages, listening for, 162
- netmasks, subnets, CIDR notation, 163
- netstat
- -a, 216
- process ID, 179
- sockets, send and receive queues, 163
- Network Manager, 166, 172, 173
- networks, persistent configuration, 157–174, 270–277
- nl, 201
- nmap
- name resolution, 186
- open ports, finding, 184
- UDP and, 215
- nptd, synchronization, time and, 147
- NTP (Network Time Protocol)
- interactive mode, 144
- internally facing, 168
- ntpdate, 211
- time, 142
- ntpdate, 211
- ntpq, messages, 143
- numbering lines, 201
- NVMe-based devices, 18
- NXDOMAIN, 173
O
- OnCalendar systemd, 136
- OpenLDAP
- corrupted, recovery, 131
- database storage, 137
- entries, adding, 129
- slapd, 126
- operators, 94, 98, 99, 100
- Orca, 112, 116, 216
- out-of-memory conditions, 50
- output, realtime viewing, 56
- overwriting files, 49, 100
- ownership of files, group ownership, 68
P
- packages
- cache update, Debian systems, 30
- CentOS, 37, 39
- Debian, 28, 31, 32, 33, 36
- information, Debian, 199
- installation, Fedora 22 system, 37
- Linux, 21–39
- RPM, downloading, 28
- upgrades, yum, 199
- upgrading, rpm, 199
- yum, 27, 28, 31
- zypper, installation, 37
- packet forwarding, number of packets, 168
- packets, statistics, 213
- pagers, backward/forward search, 58
- parameters, wireless devices, 168
- partitions
- bad blocks, 73
- GRUB, 26
- images, 49
- initial sector, 33
- Linux systems, 27, 67
- lsblk, 200
- LVM (Logical Volume Manager), initializing, 30
- mail servers, 26
- MBR system, 26, 77
- mounting and, 67
- swap partitions, formatting, 70
- type 0x82, 67
- UUID, 74
- passwd, 187, 214
- passwordfile, /etc/passwd, 49
- passwords
- age, 187
- change, 191
- change date, 129
- changing, 129
- encrypted, 131
- expiration, 210
- files, 125, 188
- getent, 136
- password-based login, 128
- unlocking accounts, 214
- x11vnc, 114
- paths, 61
- ~/code/bin, 208
- removing from results, 69
- PCI devices, 196
- permissions
- chmod, 90
- editing, simultaneous, 79
- execute, 97
- granting, 78
- ls command, 88
- root privileges, 189
- setgid, 80
- persistent configuration, 157–174, 270–277
- pgrep, 57
- ping, 161, 166, 213
- pkill, 61
- plaintext files, octal representation, 202
- pointer keys, X session, 114
- POP3, DNS and, 173
- port scans, TCP connect, 187
- port-forwarding, local session, 183
- ports
- port-to-protocol translation, 163
- POSIX (Portable Operating System Interface), umask and, 68
- Postfix server
- email aliases, 152
- mail delivery, errors, 151
- mail queue, 144, 147, 150, 152, 154
- messages, 146, 150, 156
- power, shutdown, 19
- practice exams
- Exam 1, 284–288
- Exam 101-500, 288–292
- prepending line numbers, 53
- printing
- adding jobs to queue, 153
- deleting jobs, 212
- directories, 54, 199
- head, default number printed, 48
- human-readable format, 205
- libraries, 199
- lpr option, 154
- queue, placing file, 145
- removing jobs, 152, 155
- tail, default number printed, 48
- users, groups, 148
- viewing jobs, 147
- wc, number of lines, 47
- private addresses, internal use, 160
- /proc filesystem, 11
- process IDs, 50, 196, 203
- processes
- child, variables, 208
- killing, 54
- priorities, 52
- reprioritizing running, 59
- running, 196
- Procmail, email forwarding, 150
- programs, crashing, 50
- protocols
- ps, aliases, 208
- PS1 environment variable, 87
- ps-based commands, 57
- public/private key pair, ssh, 179
R
- RAID (Redundant Array of Inexpensive Disks), 17
- RAM, video cards, 112
- rc files, runlevels, 13
- RDP (Remote Desktop), 114, 119
- read access, granting, 78
- README file, missing, 96
- readonly, 99
- read-only mode, filesystem mounting, 77
- read-only variables, 91, 93
- read-write mode, 74
- reboot, commands,
- recursive copy, symlinks, 202
- Red Hat, 15, 217
- regular expressions, 59
- remote desktop, 113, 115
- remote forwarding, SSH, 191
- remote hosts, port setting, 183
- remote servers, command execution, 181
- remote system logging, 156
- removable media, mount points, FHS, 70
- repositories, yum, 29
- rm, 55
- rmdir, 48
- rmmod, module, unloading, 11
- ro, GRUB file, 29
- root user, home directory, 27
- route, 167, 168, 171
- rpm, 28, 29, 31, 38, 199
- RPM, packages, downloading, 28
- rpm2cpio, output location, 27
- RSA-based key pairs, 181, 184
- rsyslogd, server listening, 147
- runlevel
- runlevels, systemctl, 16
- running tasks, backgrounded, 53
S
- SAN (storage area network), 11
- SATA (Serial Advanced Technology Attachment)
- disks, 197
- identifiers, 25
- sayHello function, 209
- scheduling
- certain time, 133
- command execution, 125
- cron, 126
- directories, 136
- listing jobs, 133
- power down and, 125
- scheduled jobs, finding, 127
- script directory, 128
- screen magnifier, 116
- screen resolution, 106
- scripts. See also Bash scripts
- answers to review questions, 245–251
- changes, 68
- command line, date, 143
- domain names, server, 162
- execute then leave, 89
- SCSI (Small Computer System Interface), 18
- searches, 55, 58, 60
- Secure Shell, ports, 164
- security, 175–192, 277–284
- sed, 47
- sendmail, 145, 146, 148, 149
- seq, delimiters, 95
- server host keys, SSH, 189
- servers
- routes, adding, 163
- setgid bit, 185
- set, 94
- setgid, file permissions, 80
- setuid bit set, 178
- shared libraries, 26
- shebang line, 97
- shell scripts, 85–101
- answers to review questions, 245–251
- DATE variable, 92
- files, existence, 90
- permission denied, 94
- shebang line, 97
- syslog, logging to, 152
- variable contents, displaying, 88
- variables, user input, 89
- shells, 85–101
- answers to review questions, 245–251
- built-in commands, 71, 91
- script, execute then leave, 89
- shutdown, 10, 19, 198
- shutdown command, 19
- SIGHUP signals, 56
- SIGKILL, 20
- single-user mode, 14
- skeleton home directory, 136
- slapadd, line number specification, 134
- slapd, 126, 130, 132
- SMART (Self-Monitoring, Analysis, and Reporting Technology), compatible hard drives, 74
- SMTP (Simple Mail Transfer Protocol), 148, 151
- snapshots, btrfs subvolumes, 76
- SNMP (Simple Network Management Protocol), ports, 162
- SOA (Start of Authority), 213
- source built-in, 100
- speech capabilities, Orca, 216
- speech recognition, KDE, 114
- SPF (Sender Policy Framework), 167
- Spice, authentication disable, 113
- .sql extension, searching for, 80
- srv/vhosts, 35
- ss, process IDs, 171
- SSD (solid-state drive), hardware, NVMe (Non-Volatile Memory Express), 17
- ssh
- authentication key, enabling, 184
- key-based authentication, 179, 184
- public/private key pair, 179
- remote host port, 183
- username change, 213
- X11 application forwarding, 187
- SSH (Secure Shell)
- custom client configuration, 189
- hosts, 182
- keys, adding, 187
- keys, virtual machine cloud deployment, 37
- new windows, X forwarding and, 105
- remote forwarding, 191
- server host keys, 189
- server-wide client, 191
- sudoers, 114
- visudo, 114
- X sessions, 110
- ssh-agent, keys, listing current, 181
- ssh-keygen, 188, 191
- Start of Authority, information display, 165
- STDERR, redirect, 52
- STDIN, mail, 217
- STDOUT, redirect, 52
- sticky bits, 69
- sticky keys, GNOME, 106
- storage, libraries, 30
- su, 181, 186
- subnets, 215
- sudo, 53, 78, 184, 214
- sudoers, SSH connection, 114
- suehring, 179
- swap partitions, formatting, 70
- swap space (Linux), 30
- activating, 34
- deactivating, 76
- determining, 50
- swapon, 39
- swapon, 39
- switch statement, 92
- symbolic links, 79
- file test operators, 99
- find, 205
- symlinks
- ln, 69
- recursive copy, 202
- sysfs filesystem, MAC addresses, 197
- syslog
- - sign in configuration, 154
- custom log files, 148
- informational messages, 143
- logging to, 152
- lp printing, 217
- syslog-ng, configuration files, primary, 148
- system architecture, –20, 220–226
- system clock, 134
- system logs, Linux directories, 155
- system services, 139–156
- access allowed, 188
- answers to review questions, 263–270
- libwrap, 191
- listening, 186
- loaded,
- preventing startup, 181, 182
- system time, 145, 146
- systemctl, 11
- processes, killing, 197
- runlevels, 16
- systemctl kill, 198
- systemd, 198
- active timer display, 136
- boot messages, 19
- booting, 17
- configuration files, , 72
- configurations, 13
- default target, 10
- GUI, boot disable, 105
- interprocess communication service units, 188
- journal, 142, 149, 172, 212
- location specification, 76
- log file, 142, 144
- logging, 142
- multi-users, 16
- network interface management, 174
- output logging, 152
- overriding configuration files, 15
- program executing, 10
- service units, listing,
- single-user mode command,
- storage, 13
- timer units, 134, 135
- udev, 197
- user init files, 14
- systemd-resolved, DNS resolution, 173
- systemd-run, timed events, 132
- systemed, timer units, 138
- SysV system
- chkconfig, services,
- init, , 15
- process termination, 19
- scripts, starting/stopping, 15
- SysVinitu environment, 198
T
- tail, 48, 51, 202
- tar files, 50
- tasks
- administrative, 124–138
- running, backgrounded, 53
- TCP (Transmission Control Protocol)
- remote system logging, 156
- wrappers, blocking hosts, 208
- tcpdump, available interfaces, 170
- tee, appending, 205
- telinit, 197
- terminal processing, 51, 56
- terminal-based interface, package management, Debian, 31
- test built-in command, arguments, not null, 92
- text, formatting, 202
- TFTP (Trivial File Transfer Protocol), PXELINUX, 15
- three-way handshake, 167
- time
- current, 125
- dmesg, 196
- environment variables, 126
- hardware clock, 143
- NTP (Network Time Protocol), 142
- setting, 153
- system clock, 134, 145, 146
- system time, offline devices, 145
- timedatectl, 134, 151
- timezones
- available, 135, 143
- current, 151
- Debian, 133, 216
- directories, 124, 217
- Linux server, 124
- systemwide, 132
- timedatectl, 151
- user home directory, 127
- top, 60, 203
- touch, 48
- tracepath, 165
- traceroute, 165
- ICMP, request and, 171
- IPv6 route traces, 172
- TCP SYN packets, 161
- traceroute, !H, 215
- traceroute6, IPv6 traceroute, 162
- traffic, route limiting, 165
- transport layer security, remote desktop, 115
- tune2fs, 73, 75, 77
- type 0x82 partition, 67
U
- Ubuntu
- accessibility, 209
- images, deploying to remote provider, 36
- udev, , 12
- udevadm commands, hotplug devices,
- UDP, nmap, 215
- UEFI (Unified Extensible Firmware Interface)
- boot configuration, 15
- boot loaders, 14
- booting, shim, 16
- UG flags, 167
- UIDs
- ulimit, memory limits, 187
- umask, POSIX format and, 68
- umount, 71, 178
- uniq, 202
- UNIX, commands, 41–61, 233–239
- unset, 87
- unset option, 97
- updates, kernels, 32
- Upstart, configuration files,
- uptime, load average information, 203
- USB (Universal Serial Bus)
- connections, information, 11
- devices, , , 10
- disks, mounting, 67
- drives, 10
- temporary disk, removing, 10
- user information, 137
- useradd
- account disabled, 210
- adding groups, 130
- home directory, 128
- password expiration, 210
- usermod, 131, 189
- usernames
- changing, 189, 213
- environment variables, 99
- files, 125
- printing, 202
- sorted list, 48
- users
- account expiring, 182
- deleting, 79, 125, 211
- directories, 130, 133
- executing commands on, 180
- expiring account, 180
- file copying, 90
- interfaces, 105–119, 251–257
- limits, 180, 181, 191
- logged in currently, 180
- login, preventing temporarily, 178
- messaging all,
- names, printing, 202
- printing, from password file, 188
- time zones, 127
- useradd, 128
- /usr/local, directories, creating, 49
- UTC (Coordinated Universal Time)
- hardware clock, current system time, 146
- output to, 212
- UUID
- lsblk and, 80
- partition identification, 72, 74
V
- variables
- Bash script, 98, 208
- child processes, 208
- DATE, 92
- environment
- declaring, 55
- localization, 127
- paper size, 135
- PS1, 87
- removing, 87
- single-line viewing, 99
- terminal device, X session, 111
- usernames, 99
- export, 101
- exported, 101
- $FILEPATH, 92
- read-only, declare, 93
- .variables.sh, 208
- vgscan, devices, filters, 39
- Vi editor
- cursor, moving, 58
- files, removing lines, 60
- insert mode, 52
- moving to line, 203
- save and exit, 51
- searches, backward, 55
- video cards, RAM, 112
- virtual machine
- boot process, 25
- bootstrapping, 205
- deployment, 36
- virtualization, 35, 39
- visudo, SSH connection, 114
- volumes, logical volumes, 18
W
- wall, user log off, 196
- Wayland protocol, 113
- wc, printing, number of lines, 47
- web server, /home/webfiles, 124
- Weston, configuration, 115
- while loops, 90, 91, 93, 101
- Wi-Fi, device configuration, 173
- wildcards, 60
- wireless devices, parameters, 168
- wireless networks, scanning for, 168
- WWN (World Wide Name), directory hierarchies, 18
X
- X
- abbreviations, 112
- authority files, 108, 115
- clients, executing, configuration file, 107
- configuration
- keyboard model, 107
- Screen section, 112
- server layouts, 112
- local client, display, 111
- SSH (Secure Shell), 110
- window information, 109
- X Display Manager, login, 116
- X forwarding, SSH server, new windows, 105
- X server
- clean exit, 108
- configuration, 107, 113
- connections, closing, 117
- defaults, restoring, 117
- error log, 117
- hosts, 110, 116
- init, 117
- resources, freeing, 117
- TCP, listening disable, 116
- user access, 210
- X session, pointer keys, 114
- X windows, 216
- X11, 118, 187
- x11vnc, passwords, 114
- xauth, 117, 119
- xauth authority file, 110
- xauth utility, X authority files, 108
- XDMCP
- BroadcastQuery packets, 118
- configuration file, 118
- host access, 108
- XFree86, hardware query, 106
- XFS filesystem, 73, 78
- xfs_check, 74
- xfs_fsr, filesystem reorganization time, 78
- xfs_metadump, progress indicator, 70
- xfs_repair, log zeroing, 77
- xfsrestore, options, 75
- xfwm4 window manager, 113
- xhost, hosts, enabling, 118
- xinit, per-user initialization, 117
- X.org, font storage, 107
- xorg.conf
- blank mode, 109
- Files section, fonts, 110
- inactivity timeout, 113
- Module section, 106
- video mode changes, 108
- Xsession, 111, 115, 118
- xzcat program, 58
Y
- yum
- configuration file, primary, 36
- package cache search, 31
- package installation, 27
- packages, 28, 199
- repositories, 29
- verification prompt, 199
- yumdownloader, dependencies, downloading, 32
Z
- zone transfer, 167
- zsh, searching for, 28
- zypper, packages, installation, 37
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