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Sound

Headphones setup

Depending on the headphones you are going to use, you must configure them according to the images below: 

Disks and System

How to list all disks and partitions

lsblk

# fdisk -l

How to list all devices and drivers

lspci -v | less

To remove write protection of usb drives 

$ sudo hdparm -r0 /dev/sdX

 How to find out hardware installed

BIOS: $ sudo dmidecode -t 0

Motherboard: $ sudo dmidecode -t 2

Processor: $ sudo dmidecode -t 4

RAM: $ sudo dmidecode -t 17

Max RAM allowed: $ sudo dmidecode -t 16

More info at https://www.linuxtechi.com/dmidecode-command-examples-linux/

Create bootable pendrive from iso image

1. Insert pendrive in USB port

2. Check what is the USB pendrive device/partition: sudo fdisk -l or lsblk

3. Unmount the device/partition: umount /dev/sdc1 (in my case, sdc1 is the USB pendrive device partition)

4. Create bootable pendrive: sudo dd bs=4M if=my_iso_image.iso of=/dev/sdc status=progress oflag=sync

In step 4, you must navigate where the iso image is before issuing the command.

How to create a partition image file for backup

sudo dd if=/dev/sdb5 of=/media/cheo/TOSHIBA_HDD/Lubuntu_backup.img oflag=append conv=notrunc,sync,noerror status=progress

The command above does the following:

• Create an image file of the sdb5 partition and copy it into an external usb hard drive (TOSHIBA_HDD)

• You can name the backup image file as you please. I chose Lubuntu_backup, but you can name it as you wish. However, BE SURE to use the file extension .img

• oflag=append conv=notrunc copy the file in the hard drive without using the whole hard drive (otherwise the whole hard drive will be wiped out and all the original data in the hard drive will be lost)

• conv=sync,noerror prevents the operation to halt if an error occurs

• status=progress shows the progress of the operation

Note that if the partition is 50GB, but the data in the partition is only 20GB, the whole 50GB of the partition will be backed up

How to restore a partition with a backup image file

sudo dd if=/media/cheo/TOSHIBA_HDD/Lubuntu_backup.img of=/dev/sdb5

How to add a newly installed operating systems into GRUB2

1. If not already installed, install os-prober

2. Run: sudo grub-mkconfig -o /boot/grub/grub.cfg or update-grub

More info: https://wiki.archlinux.org/index.php/GRUB

Edit GRUB2 boot options

Edit /etc/default/grub and make intended changes

Then run:

$ sudo grub-mkconfig -o /boot/grub/grub.cfg

Make a bash script executable

$ chmod +x mybashscript.sh

• Add an alias to the bash script

$ gedit ~/.bashrc

alias <new name>='/home/<full path to script>/mybashscript.sh'

• Apply the changes in the system

$ source ~/.bashrc

List of data recovery distros

• Parted Magic

• System Rescue CD

How to create a Parted Magic bootable USB

• Download the latest Partde Magic ISO image from the download page

• Plug in your USB stick and wait 5 seconds to allow enough time for the system to detect it

• Unmount the USB stick if auto-mount is enabled or if it was already mounted

• Run dd if=/path/to/partedmagic.iso of=/dev/sdx in a shell where sdx is the USB stick

How create a System Rescue CD bootable USB

• Download the latest SystemRescueCd ISO image from the download page

• sudo mkdir -p /mnt/iso

• sudo mount -o loop,exec Downloads/systemrescuecd-x86-5.2.2.iso /mnt/iso

• Plug in your USB stick and wait 5 seconds to allow enough time for the system to detect it

• Unmount the USB stick if auto-mount is enabled or if it was already mounted

• cd /mnt/iso

• sudo bash ./usb_inst.sh

• In the dialog that opens*, navigate the correct USB device with the up and down arrow keys, press space bar to select it and press enter

• cd

• sudo umount /mnt/iso

*If you are not using xterm-256color, the dialog won't open and the terminal will throw: Error opening terminal: xterm-256color

List of disk partition command-line utilities

• fdisk

• parted

• gdisk

• cfdisk

List of data recovery command line tools

• ddrescue

• testdisk

df y du (espacio ocupado y disponible en disco)

df -h

du -hc *

du -shc /usr/*

Compress/Decompress directory

• Compress: tar -zcvf mydir.tar.gz mydir

• Decompress: tar -zxvf mydir.tar.gz

How to get a list of all directories and files

find / -type f

How to count the number of all directories and files

find / -type f | wc -l

How to find specific text in files in current directory and child directories

grep -d recurse "text"

How to find all files with specific text 

grep -rnw '/path/to/somewhere/' -e 'pattern'

https://askubuntu.com/questions/607656/how-to-copy-directories-and-files-from-a-corrupted-harddrive

ddrescue

ddrescue is a tool designed for cloning and recovering data. It copies data from one file or block device (hard disc, cdrom, etc) to another, trying to rescue the good parts first in case of read errors, to maximize the recovered data. 

To clone a faulty or dying drive, run ddrescue twice. First round, copy every block without read error and log the errors to rescue.log. 

# ddrescue -f -n /dev/sdX /dev/sdY rescue.log

Second round, copy only the bad blocks and try 3 times to read from the source before giving up. 

# ddrescue -d -f -r3 /dev/sdX /dev/sdY rescue.log

Now you can check the file system for corruption and mount the new drive. 

# fsck -f /dev/sdY

https://wiki.archlinux.org/index.php/disk_cloning

Goodies

bash-completion

bc (CLI calculator)

galculator (GTK+ scientific calculator)

xfce4-screenshooter (screenshot utility)

gnome-screenshot (screenshot utility)

ristretto (image viewer utility)

transmission-gtk (torrent client)

leafpad (text editor)

nethogs (CLI network processes monitor)

vifm (vi type file manager)

obs (screencasting software)

screenkey (key press screencasting)

sensors (CLI temperature monitoring)

darktable (raw photo editing)

rawtherapee (raw photo editing)

nodejs

gatsby-cli

textlive-full, texmaker, latex2html, pandoc

for gatsby: sudo chown -R $USER:$(id -gn $USER) /home/cheo/.config

Apps

blender, gimp, krita, inkscape, darktable, kdenlive, shotcut, openshot, obs-studio, simplescreenrecorder, audacity, vlc, ffmpeg

freecad, librecad, openscad

Windows

Clean and format pen drive in Windows with Diskpart (Windows 10)

1. Launch CMD

2. diskpart

3. list disk

4. select Disk 2 *

5. clean

6. create partition primary

*On step 4, choose the correct disk number for your pen drive

Assign a letter to a drive

Sometimes, when plugging a hard drive or usb drive, Windows does not assign a letter and the drive is not shown in the Explorer. This is how to fix it:

• Launch 'Computer Management' -> Storage - Disk Management

• Look for the drive without a letter -> Right click -> 'Change drive letter and path' -> Add -> Assign the following drive letter

How to create a bootable Windows 10 USB pendrive from Linux

1. Download Windows 10 from here. Then follow these commands:

2. Insert USB pendrive (in this example in /dev/sdd

3. Issue these commands:

$ sudo add-apt-repository ppa:nilarimogard/webupd8

$ sudo apt update

$ sudo apt install woeusb

$ sudo woeusb --target-filesystem NTFS --device Downloads/Win10_1809Oct_English_x64.iso /dev/sdd

Export Wordpress site

SOURCE MACHINE

Compress/Decompress directory

• Compress: tar -czf example.tar.gz -C /var/www/example.com/public_html .

• Decompress: tar -xzf example.tar.gz -C wordpress

MariaDB

How to export database:

$ mysqldump -u wpuser -p example --single-transaction --quick --lock-tables=false > example-dump.sql

Send files to Destination Machine

• wp_importer

• database_name-dump.sql

• mydomain.tar.gz

DESTINATION MACHINE

• Create empty database: 

$ sudo mariadb -u root -p

MariaDB> CREATE DATABASE example;

MariaDB> EXIT

• Add database to MariaDB: 

$ mariadb -u wpuser -p example < example-dump.sql

• Execute bash script: 

$ sudo ./wp_importer

• Restart LEMP: 

$ sudo systemctl restart nginx php-fpm mariadb

You can login now to Wordpress dashboard by navigating to: http://example.com/wp-admin

OpenSSH

Connect to remote machine:

$ ssh user@remote_machine_ip

Note: if the remote machine you used to ssh has been deleted and a new system has been installed in the same remote machine with the same user and IP address, issue this command:

ssh-keygen -f "/home/cheo/.ssh/known_hosts" -R "192.168.1.43"

Generate a Key Pair:

$ ssh-keygen

Copy the Public Key to remote machine:

$ ssh-copy-id

How to copy a file from local to remote (from local shell):

scp file_name user@remote_machine_ip:/home/remoteuser/

How to copy a file from remote to local (from local shell):

scp user@remote_machine_ip:file_name /home/localuser/

LaTeX

Installation

$ sudo apt install texlive-full texmaker

Note that texlive-full installs all packages available for texlive (~5GB). You may want to install just texlive-base and only some other packages that you will use.

Tips

• Add linkable table of content:

\usepackage{hyperref}

• Add Japanese text support:

\usepackage{CJKutf8}

\begin{document}

\begin{CJK}{UTF8}{min}

日本語

\end{CJK}

\end{document}

• Add Yen currency character:

\def\yen\\{{\setbox0=\hbox{Y}Y\kern-.97\wd0\vbox{\hrule height.1ex

width.98\wd0\kern.33ex\hrule height.1ex width.98\wd0\kern.45ex}}}

\begin{document}

The  cost is 108\yen\\

\end{document}

• Auto generate table of contents:

  • Add the line \tableofcontents between \begin{document} and \newpage

  • Each section must be preceded by \newpage:

  • For the new changes to take affect, you must comment and uncomment \tableofcontents:

    1. %\tableofcontents

    2. Run

    3. \tableofcontents

    4. Run

GRUB v2

The configuration file is /boot/grub/grub.cfg, but you shouldn't edit it directly. This file is generated by grub v2's update-grub(8), based on: 

1. The script snippets in /etc/grub.d/ 

2. The configuration file /etc/default/grub 

To configure GRUB "v2", you should do any or both of these: 

• edit /etc/default/grub, then run update-grub

• modifying the snippets in /etc/grub.d/

Also check the GRUB2 page for more detailed configuration instructions, ideas and suggestions.