###### tags: `Sys.management`

# Résumer cours

## cours du 11.11.2021
### connection raspi au wifi
mettre la carde sd
dans boot créer un fichier en fichier txt sans le ".txt" avec le nom
**ssh**

sur le boot créer un fichier **wpa_supplicant.conf** ouvrir le fichier dans visual code et insérer

    network={
    ssid="solidus"        // nom du wifi _2.4G si le raspberry n'as pas la technologie 5G
    psk="soliduscup15"    //Mp du wifi
    }

ou bien mettre le code directement dans le fichier wpa_supplicant.conf

---

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=CH

network={
        scan_ssid=1
        ssid="<Name of your wireless LAN>"
        psk="<Password for your wireless LAN>"
        proto=RSN
        key_mgmt=WPA-PSK
        pairwise=CCMP
        auth_alg=OPEN
}

raspi-config
sudo raspi-config

changer le nom de l'hote avec **grjpi**

reboot

---


htop
ls
ping google.ch
hostname

---
**---**

---
## cours 15.11.2021 raspberry sur la machine virtuelle

### dans la machine virtuelle

**sudo apt install mosquitto-pub**
**sudo apt install mosquitto-sub**

**mosquitto**

**man mosquittopub**

**mosquittopub -h tcp://mqtt.eclipseprojects.io -t hftm -m test**

**mqtt.nomdumqtt.io**

**hostname -i : donne l'adresse IP**

mosquitto_pub -h mqtt.nom.io -t hftm/roapo/ip -m message

mosquitto_sub -h mqtt.nom.io -t hftm/roapi/ip
souscription à la "chaine" mqtt

---
### quelques commandes
ls -h
ls -lisah
ls -lisah .bashrc
nano .bashrc

hostname -i | mosquitto_pub -h mqtt.nom.io -t hftm/roapi/ip -s

reboot

boot/auto login console

fichier bashrc qui se fait tout seul quand on ouvre la console..

---
---
--- --- --- -- -- - -- - -- --- ---- ----- ----- ------ ---
### crontab -e

---
@reboot hostname -i | mosquitto_pub -h mqtt.nom.io -t hftm/roapi/ip -s

- -------------------------------------------------
-
-

----

## use mosquitto / Cours du 24.11.2021
startfile

bash.rc (console)

/etc/rc.local

sudo nano rc.local

deuxième ligne avant exit:

hostname -i | mosquitto_pub -h mqtt.eclipseprojects.io -t hftm/roa/pi -s

sync
sudo reboot

sudo nano /etc/rc.local
sudo apt install mosquitto-clients
sudo apt install mc

sudo reboot

hostname

hostname -i
hostname -h
ifconfig
dans wlan0 : inet ...(chiffre)
ifconfig | grep inet

hostname -I

( pour fenêtre d'aide man hostname)
sudo raspi-config

---
### Quelques commande à faire
**mkdir** :création de dossier
**touch** création de fichier
**nano** nom de fichier: écrire dans le fichier
**cat** ou **less** nom de fichier : lire/ ouvrir et voir le contenu du fichier
**tree** : regarder la structure
**mc** : ouvre jsp quoi mais apparement c'est utile
sudo find -name "nom dossier/ fichier"
grep: chercher par mot/ partie de mot dans les fichiers (pour trouver un fichier)
sudo grep "mot à chercher" * -r

---
ouvrir mqtt explorer:
pour voir l'addresse IP

---
windows links harddiskShell


## Sy.Man 08.12.2021

### connecter au rapsi:

ping + "nom du raspi"

exemple:

ping germpi

### Recherche/mot clés
List your processes on the system

ps

ou

top
htop

---
Pour créer des nouveaux mots pour travailler on peut utiliser

alias

---
Trouver la différence entre deux fichier

diff

exemple:

diff train train2

---

ls -l -R | grep java

### look at all

ls -all
### Redirecting Output

exemple:

ls -l

date > train (remplace tout)
somthing >>file.txt (ajoute something)
la date sera inscrite dans le fichier train

---
### The output of one command can become the input of another
faire plusieurs instructions avec | (pipe)

ps -aux |grep apache2 |wc
ps -aux |grep apache2 |wc -l

### install node-red
sudo apt install node-red

### créer un nouvel utilisateur

adduser
sudo adduser hftuser
ls -l ( pour voir les dossiers)

pour se connecter à un utilisateur

su visitor
exit

### file types / location
file:

file timezone
file get-pip.py
file start.txt
file mosquitto-pub

type: pour trouver ou sont les fichier

type mosquitto
type ls

---

commande apperçu détail fichier (owner,...)

ls -l /etc
chmod 755 file (changer les droit du fichier)

### mettre a jour

sudo apt update
sudo apt upgrade

### chmod

chmod +x fileName
chmod 744 filname

### modifier qqch dans mosquitto

sudo nano /etc/mosquitto/mosquitto.conf

### regarder les application en cours

htop

### chercher qqch

example mosquitto:
ps -aux | grep mosquitto

### lien

ln
ln -s (pour symbolic)
ln testprog newlink

### regarder dans les fichiers

ls
ls -l
ls -lisah

### pour ne pas bloquer la console avec une longue action

tree / >> directory
pour arreter = ctrl + c

sshd d = demon web server

### créer un fichier exe

nano scipte
#!/bin/bash

...

chmod 744 scripte (donné les droit pour executé)
7 = tous les droits
+4= read
+2= write
+1=execute

premier chiffre pour owner permission
deuxième chiffre pour group permission
troisième chiffre pour others permission

./scripte (il execute le fichier)

### comment

#simple line comment

: '
long comment
long comment
long comment
long comment
long comment
'

## créer un serveur mqtt perso
#### install mosquitto

sudo apt install mosquitto

ps -aux | grep mosquitto

mettre le nom du raspi dans broker Adress

- sudo systemctl start
- sudo systemctl restart (après avoir modifier qqch)
- sudo systemctl stop
- sudo systemctl status
-

systemctl status mosquitto.service
systemctl start mosquitto.service
systemctl stop mosquitto.service
sudo systemctl restart mosquitto.service

#### example mqtt


### démarrer une application tjrs au démmarage

sudo systemctl enable name
sudo systemctl disable name

example:
sudo systemctl enable mosquitto.service

## exercice:
### exercice 1

cd /home
tree
cd /home/pi
mkdir sport
cd sport
mkdir volley ski athletics tennis volley
cd volley
touch volleyplan skiplan
nano volleyplan
nano skiplan
mv ./skiplan ../ski/skiplan
cp ./volley/volleyplan ./athletics/athleticsplan
cp ./volley/volleyplan ./tennis/tennisplan
tree
df
ps
kill 941
ps
sudo adduser visitor
su visitor
chmod 777 /home/pi
ln -s /home/pi/sport/tennis/tennisplan linktennis
rm tennisplan

### exercice 2 shell linux / fichier script

ls /usr/bin | file *.ziprm
sudo dnf install vlc
cvlc v4l2:///dev/video0

nano hello
#!/bin/bash
read user
if [ "$user" = "pi" ]; then
echo "hi Mr. Gerber your last login was:"
last pi | head -n2 | tail -n1
else
echo "hello $USER"
fi

read a
read b
read sign

if [ "$sign" = "+" ]; then
echo $[$a+$b]
fi

if [ "$sign" = "-" ]; then
echo $[$a-$b]
fi

if [ "$sign" = "*" ]; then
echo $[$a*$b]
fi

if [ "$sign" = "/" ]; then
echo $[$a/$b]
fi

#!/bin/bash
for ((i=10; i>0;i--)) do
echo "$i"
done

#!/bin/bash
echo "nbr ?"
read nbrStudent
echo "Number of Student: $nbrStudent">>file.txt
for ((i=1; i<nbrStudent+1;i++)) do
echo "Name student $i:"
read name
echo "Student $i: $name">>file.txt
done

### exécuter un fichier

./hello (il execute le fichier)[]

## Crone 14.12.2021
Si vous voulez éditer un fichier crontab de l’utilisateur actuel, tapez la commande suivante dans le terminal :

crone -e

Si vous souhaitez modifier le crontab d’un autre utilisateur, vous pouvez taper :

(sudo) crontab -u [utilisateur] -e

Si vous voulez supprimer le fichier crontab actuel de l’utilisateur actuel, tapez la commande suivante :

crontab -r

L’option suivante est la même que -r, mais elle invite l’utilisateur à choisir une option oui/non avant de supprimer le crontab :

crontab -i

### utiliser node-red

d'abord sur le raspi :

node-red-start

ensuite sur le computer:

http://germpi.hftm.ch:1880

## program example



### show on the sehll from a script


### conditionel way to write
<li> three way to do the same AND</li>


<li> three way to do the same OR</li>

-o
||

### case


### loops

-<li><Strong>break</Strong> will end the loop</li>
-<li><Strong>continu</Strong> will skip 3 and 7 in this example</li>

### input script
<Strong>STIN</Strong> standart input


#### with arrays

-<li><Strong>$#</Strong> will give the lenght of the array</li>

#### read a file

-<li><Strong>if we don't select any file</Strong> it will use the terminal</li>

-<li>read the file and print it in the terminal</li>

### script output

<Strong>STDOUT / STDERR </Strong> standart output and error

-<li>this is the standard output</li>

-<li>this is the standard error</li>

-<li>1 is the standard output and 2 is the standard error</li>

-<li>it assumes it is a standard output </li>

-<li>same file for the two standard</li>

## résumé commande
---
https://www.linux.org/threads/more-useful-commands.4131/

---

### make a file looks like it was done the 07 mai at 09h15
Code:

touch -t 05070915 my_report.txt
touch [a file name]

### find

Code:

find -name *hawaii

You may have created some file recently. For example, you may want to find some file that you were working on, let's say from now up to 10 minutes ago, you could type.

Code:

find -mmin +0 -mmin -10

### pico
Create a file with 'pico' or any Linux text editor, create a file called 'mary1.txt'

Code:

pico mary1.txt

### grep
Let's explain this a little. 'grep' looks for the word "Mary" in any text file that is called "mary(something).txt". You've created three files that start with 'mary', so the asterisk makes sure that 'grep' will look for the word 'Mary' in all three.

Code:

grep Mary mary*.txt

### who
'who' is a command to find out who's working on your system. As you now know, Linux is a multi-user system. Even if you're using one computer at your home, you may be working as more than one person. For example, if you logged in as 'root' but are working as 'bob'.

who

### tee
tee' is used to write out what appears on your screen into a file. You will be using this with the after a pipe '|' .
You might do this:

Code:

ls -l | tee directory_listing

to get a file with the listing of a directory. If you've placed files in a directory to be backed up, you could use this command to create a listing of that directory. You could print out the file on a label and stick it to the disk, tape, zip cartridge or whatever you used to make the backups.

If you're using the 'tee' command for the backups I described before, you may want to put a date on the file. You can use this command:

#### date
Code:

date | tee -a directory_listing

The command 'date' will enter the date and time in the file at the end. Remember to use the -a option if you're going to write to that file a second time. If you don't you will erase everything on the file in favor of whatever the second command was.

### The '>' command

The "greater than" symbol '>' will do the same as 'tee'. You don't need the pipe command (|) with this one.

Code:

ls -l > directory_listing

will give you the same result. If you want to add the date at the end, use the command:
#### >>
Code:

date >> directory_listing

with two "greater than" symbols (>>)

The two symbols will add to the file without erasing its contents (appending).

### whatis

To show you how to use the 'whatis' command 'whatis' is a command so you can find out what a program does. If you explore your Linux system, you will find a lot of programs and you may not know what they do. You would simply type:
Code:

whatis grep

### whereis

whereis is a nice command for finding other commands or programs. If you decide to download any program from the internet, that program may need other programs in order to work. If you want to know whether or not you have it, you can type:
whereis [program name]
and find out.

If you wanted to find out if you have the 'pico' editor and where it is, you would type:

Code:

whereis pico

which

To show you another tool for locating programs 'which' is similar to 'whereis'. It will give you the location of a program. At times, a program may not find another program it needs to make it run. It will need to know its location or "path". For example, a program may need Java to run it but thinks its in another place. You would simply type:

Code:

which java

### echo

To show you some uses of the 'echo' command 'echo' is a little command that repeats anything you type. For example if you type
Code:

echo hello
Linux will display the word 'hello' .

There is a practical use for 'echo' in everyday life. I sometimes use it to write short notes. If we use 'echo' along with 'pipe' (|) and 'tee', you've got a poor-man's post-it-note.

For example:

Code:

echo remember to tell Bill Gates he owes me 5 bucks | tee -a bill_gates.note

Will make you a nice reminder note about dear 'ole Bill. Just remember to read your note. You could type:

Code:

echo remember to open Gates note | tee -a remember_gates.note

to make yourself a reminder for the other reminder note. Use less bill_gates.note or less remember_gates.note to read your notes

### wc

Actually, this command will give you the number of lines, words and letters (characters) in a file and in that order.

Let's go back to the file about the people I owe money. If I type:

Code:

wc people_I_owe_money.note

I will get this output:

439 6510 197120 wc people_I_owe.note

As you can see, there are 439 lines, so that means if each line represents one person, then I owe 439 people money. There are 6510 words and a total of 197120 characters.