====== How-tos (Some useful Linux tips) ======

===== Multimedias - Conversions =====

==== Convert Wav to Flac ====
Convert all wav files to flac files in a folder

<code bash>
for i in *.wav; do ffmpeg -i "$i" "$i".flac ; done
</code>


==== Convert Flac to Mp3 files ====

<code bash>
for f in *.flac; do flac -cd "$f" | lame -b 320 - "${f%.*}".mp3; done
</code>



==== Compress all mp4 videos in a folder ====
<code bash>
for i in *.mp4; do ffmpeg -i "$i" -vcodec libx265 -crf 28 "${i%.*}_compressed.mp4"; done
</code>

==== Compress all mov videos in a folder ====

<code bash>
for i in *.mov; do ffmpeg -i "$i" -vcodec libx265 -crf 28 "${i%.*}_compressed.mp4"; done
</code>
==== Convert HEIC images to jpg ====
<code bash>
sudo apt install libheif-examples
for file in *.heic; do heif-convert "$file" "${file/%.heic/.jpg}"; done
</code>
==== Pick a random file with Totem ====
<code bash>
totem "$(ls -R | shuf -n1)"
</code>

==== Compress PDF files ====

<code bash>
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/default \
    -dNOPAUSE -dQUIET -dBATCH -dDetectDuplicateImages \
    -dCompressFonts=true -r150 -sOutputFile=output.pdf input.pdf
</code>



==== If Totem can't read some mkv or mp4 vidéo ==== 
After upgrading to Ubuntu 22.04 I had some issue to read some video files (Totem crash at startup, display the error "The specified movie could not be found" or open the video with a strange format. 
I did install the Intel non-free drivers to solve this issue:
<code bash>
sudo apt install intel-media-va-driver-non-free ubuntu-restricted-extras
</code>

===== Files =====
==== Remove files recursively ====

<code bash>
# remove lrc files
find -type f -name "*.lrc" -delete
# remove .DS_Store files
find -type f -name ".DS_Store" -delete
</code>

==== Remove duplicate files ====

<code bash>
fdupes -rdN .
</code>

==== Uncompress .tar.gz file ====
<code bash>
tar -zxvf file.tar.gz
</code>

==== Uncompress .tar.bz2 file ====
<code bash>
tar -xvjf file.tar.bz2 
</code>


==== Remove empty folders ====
<code bash>
find . -type d -delete
</code>

==== Search .Mp3 files ====
<code bash>
find . -iname "*.mp3" -print
</code>

===== Network =====

==== Download test ====
<code bash>
curl -4 -o /dev/null http://bouygues.testdebit.info/100M.iso
</code>

==== Upload test ====
<code bash>
curl -o /tmp/temp.iso https://bouygues.testdebit.info/100M.iso
curl -4 -o /dev/null -F "filecontent=@/tmp/temp.iso" http://bouygues.testdebit.info
</code>

==== Display public IP address ====
<code bash>
host myip.opendns.com resolver1.opendns.com
</code>

==== Open ports connexions ====

<code bash>
sudo netstat -antp
</code>


==== Connected users list ====
<code bash>
who
</code>

==== Disconnect a user ====
<code bash>
sudo slay user_name
</code>

==== Firewall - Status ====

<code bash>
sudo ufw status verbose
</code>

==== Trafic - bandwidth utilisation ====


<code bash>
sudo iftop -i enp9s0
</code>

==== SSH - Launch X application over SSH ====
<code bash>
ssh user@host -XC application
</code>

==== FTP - Add user ====
<code bash>
ftpasswd --passwd --name=bob --uid=1001 --home=/home/bob --shell=/bin/false
</code>


==== NcFTP - connection ====

<code bash>
ncftp -u username -p apssword ftp://ftpperso.free.fr/dir/
</code>

==== NcFTP - folder copy ====

<code bash>
sudo ncftpput -R -u username ftpperso.free.fr / /dir_to_copy/*
</code>

===== Hardware  =====

==== Component list ====

<code bash>
sudo lshw | more
</code>

==== Getting SMBIOS data from sysfs==== 

<code bash>
sudo dmidecode
</code>

==== CPU information ==== 
<code bash>
sudo lscpu
</code>

==== Battery information ====

<code bash>
upower -i /org/freedesktop/UPower/devices/battery_BAT0
</code>


==== Check Wifi signal ====
<code bash>
wavemon
</code>
===== System =====

==== Monitor ====

<code bash>
sudo glances --enable-plugin sensors
</code>


==== CPU frequency ====
<code bash>
cpufreq-info
</code>


====  CPU Over temperatures Log occurrences ====

<code bash>
sudo journalctl --since "2023-01-01" | grep temperature
</code>


==== Power Usage ====

<code bash>
sudo powertop
</code>

==== Security: detect signs of rootkits====

<code bash>
sudo chkrootkit
</code>
===== Hard-drive =====

==== Folders/files usage ====
<code bash>
sudo gt5
</code>


==== Disk - Free space on /boot partition ====

<code bash>
//check current kernel
uname -r
//check if list of old kernels is correct 
dpkg -l linux-{image,headers}-"[0-9]*" | awk '/^ii/{ print $2}' | grep -v -e `uname -r | cut -f1,2 -d"-"` | grep -e '[0-9]'
//purge old kernels
dpkg -l linux-{image,headers}-"[0-9]*" | awk '/^ii/{ print $2}' | grep -v -e `uname -r | cut -f1,2 -d"-"` | grep -e '[0-9]' | xargs sudo apt-get -y purge
</code>

==== SMART information ==== 
<code bash>
sudo smartctl -A /dev/sda
</code>

==== Set HD to low power consumption standby mode ====
<code bash>
sudo hdparm -y /dev/sdb
</code>

==== Hard drive current state ====

<code bash>
sudo hdparm -C /dev/sdb
</code>

==== Hard drive current Advanced Power Management (APM) value ====

<code bash>
sudo hdparm -B /dev/sdb

</code>

==== Change APM value  ====
60 = 5x60 = (5 minutes)
<code bash>
sudo hdparm -B60 /dev/sdb
</code>

===== Fstab =====
Install cifs/nfs
<code>
sudo apt install nfs-common
sudo apt install cifs-utils
</code>



===== Install DCP-7055W scan driver =====

<code bash>
brsaneconfig4 -a name=(name your device) model=(model name) ip=xx.xx.xx.xx
</code>

https://support.brother.com/g/b/downloadhowto.aspx?c=us_ot&lang=en&prod=dcp7055w_us_eu_as&os=128&dlid=dlf006645_000&flang=4&type3=566



===== Fail2ban =====

Get SSH banned IP
<code bash>
fail2ban-client status sshd
</code>

===== Nginx ===== 
==== GoAccess - Log statistics (terminal) ====

  * Live statistics
<code bash>
tail -f access.log | goaccess -
</code>

  * Using single log file
<code bash>
goaccess access.log
</code>

  * Using all log files (including .gz files) 
<code bash>
zcat -f access.log* | goaccess -
</code>

  * Date ranges
<code bash>
sed -n '/'$(date '+%d\/%b\/%Y' -d 'last week')'/,$ p' access.log | goaccess -a -
sed -n '/'$(date '+%d\/%b\/%Y' -d 'last month')'/,$ p' access.log | goaccess -a - 
sed -n '/'$(date '+%d\/%b\/%Y' -d '1 month ago')'/,$ p' access.log | goaccess -a - 
sed -n '/'$(date '+%d\/%b\/%Y' -d '1 week ago')'/,$ p' access.log | goaccess -a - 
sed -n '/'$(date '+%d\/%b\/%Y' -d 'yesterday')'/,$ p' access.log | goaccess -a - 
sed -n '/'$(date '+%d\/%b\/%Y' -d 'today')'/,$ p' access.log | goaccess -a -
</code>
==== GoAccess - Log statistics (dynamic HTML page) ==== 
<code bash>
goaccess access.log -o /var/www/html/report.html --log-format=COMBINED --real-time-html
</code>
==== Count pages sorted by response code ====

<code bash>
awk '{print $9}' access.log | sort | uniq -c | sort -rn

</code>
==== Count 404 respond code ====

<code bash>

cd /var/log/nginx/
awk '($9 ~ /404/)' access.log | awk '{print $7}' | sort | uniq -c | sort -rn


</code>

==== Hotlink ====

<code bash>
awk -F\" '($2 ~ /\.(jpg|gif)/ && $4 !~ /^https:\/\/eolienne\.f4jr\.org/){print $4}' access.log | sort | uniq -c | sort
</code>



==== List of 20 most connected IP address (since a date) ====

<code bash>
awk '/Jan\/2024/ {print $1};' access.log | sort | uniq -c | sort -rn | head -20
</code>

==== Top 10 IP address sort by bandwidth utilization ====

<code bash>
awk 'BEGIN{ PROCINFO["sorted_in"]="@val_num_desc" }
     { a[$1]++; b[$1]+=$10 }
     END{ 
         for(i in a) { if(++c>10) break; printf "IP: %s: ",i ; system(sprintf("numfmt --to=iec-i %s",b[i])) ; } 
     }' access.log
</code>
===== MySQL =====

==== Secure  ====

<code bash>
sudo /usr/bin/mysql_secure_installation
</code>

==== Create backup user ====

<code bash>
sudo mysql -uroot -p
GRANT LOCK TABLES, SELECT, RELOAD ON *.* TO 'backup'@'localhost' IDENTIFIED BY 'PASSWORD';
</code>

==== Password for backup ====
<code bash>
/etc/mysql/conf.d/mysqldump.cnf
</code>

==== Create database ====

<code bash>
mysql -p -u root

CREATE DATABASE db_name;

GRANT ALL PRIVILEGES ON db_name.* TO 'db_user'@'localhost'
IDENTIFIED BY 'password' WITH GRANT OPTION;
</code>

==== Connect to database ====
<code bash>
mysql -p -u root -D db_name
</code>

==== Show tables ====
<code bash>
SHOW TABLES ;
</code>






===== AirPlay =====

==== Pulse Audio ====

Installation of Airplay in Ubuntu 22.04 with Pulse Audio

  * https://bugs.launchpad.net/ubuntu/+source/paprefs/+bug/1871899?comments=all
<code bash>
# Airplay ability 
sudo apt install pulseaudio build-essential paprefs git pulseaudio-module-raop intltool libjack0 pavucontrol pulseaudio-module-zeroconf

#bug pulseaudio 
sudo ln -s /usr/lib/pulse-16.1+dfsg1/ /usr/lib/pulse-16.1
pactl load-module module-raop-discover
</code>

==== PipeWire ====

Discover Airplay in Ubuntu 22.10 with PipeWire

<code bash>
sudo vi /etc/pipewire/pipewire.conf
</code>
Add the following line to load module inside the //context.modules = [// section

<code bash>
{ name = libpipewire-module-raop-discover }
</code>


===== HandBrake =====


<code bash>
sudo apt install libdvdnav4 libdvdread4 gstreamer1.0-plugins-bad gstreamer1.0-plugins-ugly libdvd-pkg
sudo dpkg-reconfigure libdvd-pkg
sudo apt install ubuntu-restricted-extras
</code>
 
===== Pi-hole =====


==== Upgrade ====
<code bash>
pihole -up
</code>


===== Gnome =====

Move the Dock 'Show Applications' button at top
<code bash>
gsettings set org.gnome.shell.extensions.dash-to-dock show-apps-at-top true
</code>

Move the windows control button to the left

<code bash>
gsettings set  org.gnome.desktop.wm.preferences button-layout 'close,minimize,maximize:'
</code>
===== Nice projects =====
  * Raspberry Pi : https://www.raspberrypi.org/ - Tiny computer 
  * Pi-Hole : https://pi-hole.net - Ad blocking using DNS - With [[https://github.com/pi-hole/pi-hole/wiki/DNSCrypt-2.0|DNSCrypt-Proxy]] 
  * Firefox : https://www.mozilla.org/en-US/firefox/new/ - The Web Browser 
  * Bitwarden : https://bitwarden.com/open-source/ - Password manager
  * MoodeAudio : http://www.moodeaudio.org/ - Audiophile-quality music playback
  * HifiBerry : https://www.hifiberry.com/ - Audio additional boards for Rpi
  * OpenHAB : https://www.openhab.org/ - Smart Home
  * DD-WRT : https://dd-wrt.com/ - Free your router 
  * Ubuntu : https://ubuntu.com/ - Linux distribution 
  * Shelly : https://www.shelly.com/en-fr - Smart Home Automation
  * Nicotine+ : https://nicotine-plus.org/ - Soulseek is not dead
  * Kodi : https://kodi.tv/ - Media Centre  
  * NGINX : https://www.nginx.com/ - Web Server
  * Amplify : https://amplify.nginx.com - Web Server Monitoring
  * VideoLAN : https://www.videolan.org/ - Powerful media player 
  * Waze : https://www.waze.com/ - GPS