• Configuring PS1 variable in Bash.bashrc

https://www.howtogeek.com/428413/what-is-reverse-ssh-tunneling-and-how-to-use-it/

zip is a simple command to archive and compress files

Help:

-9 : number 9 is the best compression level, use 0 for no compression. The highest compression level is the slowest. 6 is a good average.

zip -9 zipfile.zip fileotadd.file

zip add -9 zipfile.zip fileotadd.file

update (-u)

Update existing entries if newer on the file system and add new files. If the archive does not exist issue warning then create a new archive.

zip -u -9 existingzipfile.zip listfileotadd.*

You need additional tool like pigz

https://www.tecmint.com/compress-files-faster-in-linux/

option (-k) to retain original file and (-9) for best compression

exemple:

tar -I "pigz -k -9" -cf dir1.tar.gz dir1

apt install openssh-server
apt install sshfs
apt install joe

Le script d'UPDATE du système:

#!/bin/bash

echo "**"
echo "*****************************"
echo "** Doing the UPDATE"
echo "*****************************"

apt --yes update

echo "**"
echo "*****************************"
echo "** Doing the UPGRADE"
echo "*****************************"

apt --yes upgrade

echo "**"
echo "*****************************"
echo "** Doing the UPGRADE of the Distro"
echo "*****************************"

apt --yes dist-upgrade

echo "**"
echo "*****************************"
echo "**   Cleaning The system"
echo "*****************************"

apt --yes autoclean
apt --yes autoremove

echo "Nightly Updates Successful: $(date)">> /tmp/updatingsystem.log

Script pour créer un point de montage et monter le repertoire distant sur le serveur correspondant à l'utilisateur connecté. Montage crypté permettant d'obtenir un cloud privé et sécurisé.

#!/bin/bash

if [ ! -d "$HOME"/EsoaCloud ];
 then
   mkdir "$HOME"/EsoaCloud
fi

sshfs 192.168.0.2:/home/"$USER" "$HOME"/EsoaCloud

To avoid exit signals propagating to child processes of the terminal and shell, run the command with nohup, i.e.:

nohup cmd &

tout d'abord un petit script bien pratique ici surtout le script de mise à jour à base de apt-get

ensuite il faut utiliser les instructions cron tout d'abord éditer les lignes de cron:

crontab -e

Puis connaitre la syntaxe: http://www.openjs.com/scripts/jslibrary/demos/crontab.php

La syntaxe de cronteb est la suivante:

minute (m), hour (h), day of month (dom), month (mon), day of week (dow)

Ce qui peut donner pour une exécution de l'instruction update une fois par semaine à 3h00 am:

0  3  *  *  1   update

https://www.tecmint.com/run-repeat-linux-command-every-x-seconds/

The next logical question is – how to change the execution interval. For that purpose, you can use the -n option, that specifies the interval with which the command will be executed. This interval is specified in seconds. So let’s say you want to run your script.sh file every 10 seconds, you can do it like this:

# watch -n 10 script.sh

Note that if you run the command like shown above, you will need to cd to the directory (learn Learn 15 cd Command Examples) where the script is located or otherwise specify the full path to that script.

Other useful options of watch command are:

1. b – creates a beep sound if the exit of the command is non-zero.
2. c – Interprets ANSI color sequences.
3. d – highlights the changes in the command output.

In Linux, while copying files from one location to other using cp command, the progress of data is not shown, to see the progress of data being copied, you can use the watch command along with du -s command to check the disk usage in real time.

# cp ubuntu-15.10-desktop-amd64.iso /home/tecmint/ &
# watch -n 0.1 du -s /home/tecmint/ubuntu-15.10-desktop-amd64.iso

If you think that the above process is too complicated to achieve, then I suggest you to go for Advance copy command, which shows progress of data while copying.

Sometime with modern system there is a drift between the hardware clock and the system clock due to mismatch local time setup. But you need to get the right time for file synchronization. It is important on a desktop computer and moreover on a server and on the system when you are using unison and so on.

First set the good date

sudo date MMDDhhmm

then synchronize hardware clock and the system time.

first copy HW clock to system time :

sudo hwclock --hctosys

https://www.tecmint.com/run-repeat-linux-command-every-x-seconds/

Then copy the System time to HW Clock:

sudo hwclock --systohc

to see the HW CLock:

sudo hwclock --show

the application is /usr/bin/users-admin