manual, sysadmins, cli

collections/system_administrators/computer_it_basics/cli_scripts_basics.md

@@ -24,6 +24,7 @@
   - [Become the superuser (su) on Linux](#become-the-superuser-su-on-linux)
   - [Exit a session](#exit-a-session)
   - [Know the current user](#know-the-current-user)
+  - [See the path of a package](#see-the-path-of-a-package)
   - [Set the path of a package](#set-the-path-of-a-package)
   - [See the current path](#see-the-current-path-1)
   - [Find the current shell](#find-the-current-shell)
@@ -127,11 +128,11 @@ You can also set a number of counts with `-c` on Linux and MAC and `-n` on Windo
 Here are the steps to install [Go](https://go.dev/).
 
 * Install go
-  * ```
+    ```
     sudo apt install golang-go
     ```
 * Verify that go is properly installed
-  * ```
+    ```
     go version
     ```
 
@@ -142,19 +143,19 @@ Here are the steps to install [Go](https://go.dev/).
 Follow those steps to install [Brew](https://brew.sh/)
 
 * Installation command from Brew:
-  * ```
+    ```
     /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
     ```
 * Add the path to the **.profile** directory. Replace <user_name> by your username.
-  * ```
+    ```
     echo 'eval "$(/home/linuxbrew/.linuxbrew/bin/brew shellenv)"' >> /home/<user_name>/.profile
     ```
 * Evaluation the following:
-  * ```
+    ```
     eval "$(/home/linuxbrew/.linuxbrew/bin/brew shellenv)"
     ```
 * Verify the installation
-  * ``` 
+    ``` 
     brew doctor
     ```
 
@@ -163,27 +164,27 @@ Follow those steps to install [Brew](https://brew.sh/)
 ### Brew basic commands
 
 * To update brew in general:
-  * ``` 
+    ``` 
     brew update
     ```
 * To update a specific package:
-  * ``` 
+    ``` 
     brew update <package_name>
     ```
 * To install a package:
-  * ``` 
+    ``` 
     brew install <package_name>
     ```
 * To uninstall a package:
-  * ``` 
+    ``` 
     brew uninstall <package_name>
     ```
 * To search a package:
-  * ``` 
+    ``` 
     brew search <package_name>
     ```
 * [Uninstall Brew](https://github.com/homebrew/install#uninstall-homebrew)
-  * ```
+    ```
     /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/uninstall.sh)"
     ```
 
@@ -194,11 +195,11 @@ Follow those steps to install [Brew](https://brew.sh/)
 Installing Terraform with Brew is very simple by following the [Terraform documentation](https://developer.hashicorp.com/terraform/downloads).
 
 * Compile HashiCorp software on Homebrew's infrastructure
-  * ```
+    ```
     brew tap hashicorp/tap
     ```
 * Install Terraform
-  * ```
+    ```
     brew install hashicorp/tap/terraform
     ```
 
@@ -207,27 +208,27 @@ Installing Terraform with Brew is very simple by following the [Terraform docume
 ### Yarn basic commands
 
 * Add a package
-  * ```
+    ```
     yarn add
     ```
 * Initialize the development of a package
-  * ```
+    ```
     yarn init
     ```
 * Install all the dependencies in the **package.json** file
-  * ```
+    ```
     yarn install
     ```
 * Publish a package to a package manager
-  * ```
+    ```
     yarn publish
     ```
 * Remove unused package from the current package
-  * ```
+    ```
     yarn remove
     ```
 * Clean the cache
-  * ```
+    ```
     yarn cache clean
     ```
 
@@ -260,11 +261,11 @@ ls -ld .?*
 You can use **tree** to display the files and organization of a directory:
 
 * General command
-  * ```
+    ```
     tree
     ```
 * View hidden files
-  * ```
+    ```
     tree -a
     ```
 
@@ -336,10 +337,10 @@ which <application_name>
 
 On MAC and Linux, you can use **coreutils** and **realpath** from Brew:
 
-* ```
+  ```
   brew install coreutils
   ```
-* ```
+  ```
   realpath file_name
   ```
 
@@ -350,11 +351,11 @@ On MAC and Linux, you can use **coreutils** and **realpath** from Brew:
 You can use either command:
 
 * Option 1
-  * ```
+    ```
     sudo -i
     ```
 * Option 2
-  * ```
+    ```
     sudo -s
     ```
 
@@ -364,10 +365,10 @@ You can use either command:
 
 You can use either command depending on your shell:
 
-* ```
+  ```
   exit
   ```
-* ```
+  ```
   logout
   ```
 
@@ -377,7 +378,7 @@ You can use either command depending on your shell:
 
 You can use the following command:
 
-* ```
+  ```
   whoami
   ```
 
@@ -387,7 +388,7 @@ You can use the following command:
 
 To see the path of a package, you can use the following command:
 
-* ```
+  ```
   whereis <package_name>
   ```
 
@@ -414,11 +415,11 @@ pwd
 ### Find the current shell
 
 * Compact version
-  * ```
+    ```
     echo $SHELL
     ```
 * Detailed version
-  * ```
+    ```
     ls -l /proc/$$/exe
     ```
 
@@ -427,35 +428,35 @@ pwd
 ### SSH into Remote Server
 
 * Create SSH key pair
-  * ```
+    ```
     ssh-keygen
     ```
 * Install openssh-client on the local computer*
-  * ```
+    ```
     sudo apt install openssh-client
     ```
 * Install openssh-server on the remote computer*
-  * ```
+    ```
     sudo apt install openssh-server
     ```
 * Copy public key
-  * ```
+    ```
     cat ~/.ssh/id_rsa.pub
     ```
 * Create the ssh directory on the remote computer
-  * ```
+    ```
     mkdir ~/.ssh
     ```
 * Add public key in the file **authorized_keys** on the remote computer
-  * ```
+    ```
     nano ~/.ssh/authorized_keys
     ```
 * Check openssh-server status
-  * ``` 
+    ``` 
     sudo service ssh status
     ```
 * SSH into the remote machine
-  * ```
+    ```
     ssh <username>@<remote_server_IP_or_hostname>
     ```
 
@@ -468,11 +469,11 @@ To enable remote login on a MAC, [read this section](#enable-remote-login-on-mac
 ### Replace a string by another string in a text file
 
 * Replace one string by another (e.g. **old_string**, **new_string**)
-  * ```
+    ```
     sed -i 's/old_string/new_string/g' <file_path>/<file_name>
     ```
 * Use environment variables (double quotes)
-  * ```
+    ```
     sed -i "s/old_string/$env_variable/g" <file_path>/<file_name>
     ```
 
@@ -529,11 +530,11 @@ date
 You can use [Dig](https://man.archlinux.org/man/dig.1) to gather DNS information of a website
 
 * Template
-  * ```
+    ```
     dig <website.tld>
     ```
 * Example
-  * ```
+    ```
     dig threefold.io
     ```
 
@@ -546,31 +547,31 @@ You can also use online tools such as [DNS Checker](https://dnschecker.org/).
 We present one of many ways to partition and mount a disk.
 
 * Create partition with [gparted](https://gparted.org/)
-  * ```
+    ```
     sudo gparted
     ```
 * Find the disk you want to mount (e.g. **sdb**)
-  * ```
+    ```
     sudo fdisk -l
     ```
 * Create a directory to mount the disk to
-  * ```
+    ```
     sudo mkdir /mnt/disk
     ```
 * Open fstab
-  * ```
+    ```
     sudo nano /etc/fstab
     ```
 * Append the following to the fstab with the proper disk path (e.g. **/dev/sdb**) and mount point (e.g. **/mnt/disk**)
-  * ```
+    ```
     /dev/sdb    /mnt/disk    ext4    defaults    0    0
     ```
 * Mount the disk
-  * ```
+    ```
     sudo mount /mnt/disk
     ```
 * Add permissions (as needed)
-  * ```
+    ```
     sudo chmod -R 0777 /mnt/disk
     ```
 
@@ -583,36 +584,36 @@ We present one of many ways to partition and mount a disk.
 You can use [gocryptfs](https://github.com/rfjakob/gocryptfs) to encrypt files.
 
 * Install gocryptfs
-  * ```
+    ```
     apt install gocryptfs
     ```
 * Create a vault directory (e.g. **vaultdir**) and a mount directory (e.g. **mountdir**)
-  * ```
+    ```
     mkdir vaultdir mountdir
     ```
 * Initiate the vault
-  * ```
+    ```
     gocryptfs -init vaultdir
     ```
 * Mount the mount directory with the vault
-  * ```
+    ```
     gocryptfs vaultdir mountdir
     ```
 * You can now create files in the folder. For example:
-  * ```
+    ```
     touch mountdir/test.txt
     ```
 * The new file **test.txt** is now encrypted in the vault  
-  * ```
+    ```
     ls vaultdir
     ```
 * To unmount the mountedvault folder:
   * Option 1
-    * ```
+      ```
       fusermount -u mountdir
       ```
   * Option 2
-    * ```
+      ```
       rmdir mountdir
       ```
 
@@ -623,27 +624,27 @@ To encrypt files, you can use [Veracrypt](https://www.veracrypt.fr/en/Home.html)
 
 * Veracrypt GUI
   * Download the package
-    * ```
+      ```
       wget https://launchpad.net/veracrypt/trunk/1.25.9/+download/veracrypt-1.25.9-Ubuntu-22.04-amd64.deb
       ```
   * Install the package
-    * ```
+      ```
       dpkg -i ./veracrypt-1.25.9-Ubuntu-22.04-amd64.deb
       ```
 * Veracrypt console only
   * Download the package
-    * ```
+      ```
       wget https://launchpad.net/veracrypt/trunk/1.25.9/+download/veracrypt-console-1.25.9-Ubuntu-22.04-amd64.deb
       ```
   * Install the package
-    * ```
+      ```
       dpkg -i ./veracrypt-console-1.25.9-Ubuntu-22.04-amd64.deb
       ```
 
 You can visit [Veracrypt download page](https://www.veracrypt.fr/en/Downloads.html) to get the newest releases.
 
 * To run Veracrypt
-  * ```
+    ```
     veracrypt
     ```
 * Veracrypt documentation is very complete. To begin using the application, visit the [Beginner's Tutorial](https://www.veracrypt.fr/en/Beginner%27s%20Tutorial.html).
@@ -661,11 +662,11 @@ ifconfig
 ### See identity and info of IP address
 
 * See abuses related to an IP address:
-  * ```
+    ```
     https://www.abuseipdb.com/check/<IP_Address>
     ```
 * See general information of an IP address: 
-  * ```
+    ```
     https://www.whois.com/whois/<IP_Address>
     ```
 
@@ -674,124 +675,124 @@ ifconfig
 ### ip basic commands
 
 * Manage and display the state of all network 
-  * ```
+    ```
     ip link
     ```
 * Display IP Addresses and property information (abbreviation of address)
-  * ```
+    ```
     ip addr
     ```
 * Display and alter the routing table
-  * ```
+    ```
     ip route
     ```
 * Manage and display multicast IP addresses
-  * ```
+    ```
     ip maddr
     ```
 * Show neighbour object
-  * ```
+    ```
     ip neigh
     ```
 * Display a list of commands and arguments for
 each subcommand
-  * ```
+    ```
     ip help
     ```
 * Add an address
   * Template
-    * ```
+      ```
       ip addr add
       ```
   * Example: set IP address to device **enp0**
-    * ```
+      ```
       ip addr add 192.168.3.4/24 dev enp0
       ```
 * Delete an address
   * Template
-    * ```
+      ```
       ip addr del
       ```
   * Example: set IP address to device **enp0**
-    * ```
+      ```
       ip addr del 192.168.3.4/24 dev enp0
       ```
 * Alter the status of an interface
   * Template
-    * ```
+      ```
       ip link set
       ```
   * Example 1: Bring interface online (here device **em2**)
-    * ```
+      ```
       ip link set em2 up
       ```
   * Example 2: Bring interface offline (here device **em2**)
-    * ```
+      ```
       ip link set em2 down
       ```
 * Add a multicast address
   * Template
-    * ```
+      ```
       ip maddr add
       ```
   * Example : set IP address to device **em2**
-    * ```
+      ```
       ip maddr add 33:32:00:00:00:01 dev em2
       ```
 * Delete a multicast address
   * Template
-    * ```
+      ```
       ip maddr del
       ```
   * Example: set IP address to device **em2**
-    * ```
+      ```
       ip maddr del 33:32:00:00:00:01 dev em2
       ```
 * Add a routing table entry
   * Template
-    * ```
+      ```
       ip route add
       ```
   * Example 1: Add a default route (for all addresses) via a local gateway
-    * ```
+      ```
       ip route add default via 192.168.1.1 dev em1
       ```
   * Example 2: Add a route to 192.168.3.0/24 via the gateway at 192.168.3.2
-    * ```
+      ```
       ip route add 192.168.3.0/24 via 192.168.3.2
       ```
   * Example 3: Add a route to 192.168.1.0/24 that can be reached on
 device em1
-    * ```
+      ```
       ip route add 192.168.1.0/24 dev em1
       ```
 * Delete a routing table entry
   * Template
-    * ```
+      ```
       ip route delete
       ```
   * Example: Delete the route for 192.168.1.0/24 via the gateway at
 192.168.1.1
-    * ```
+      ```
       ip route delete 192.168.1.0/24 via 192.168.1.1
       ```
 * Replace, or add, a route
   * Template
-    * ```
+      ```
       ip route replace
       ```
   * Example: Replace the defined route for 192.168.1.0/24 to use
 device em1
-    * ```
+      ```
       ip route replace 192.168.1.0/24 dev em1
       ```
 * Display the route an address will take
   * Template
-    * ```
+      ```
       ip route get
       ```
   * Example: Display the route taken for IP 192.168.18.25
-    * ```
+      ```
       ip route replace 192.168.18.25/24 dev enp0
       ```
 
@@ -804,23 +805,23 @@ References: https://www.commandlinux.com/man-page/man8/ip.8.html
 ### Display socket statistics
 
 * Show all sockets
-  * ```
+    ```
     ss -a
     ```
 * Show detailed socket information
-  * ```
+    ```
     ss -e
     ```
 * Show timer information
-  * ```
+    ```
     ss -o
     ```
 * Do not resolve address
-  * ```
+    ```
     ss -n
     ```
 * Show process using the socket
-  * ```
+    ```
     ss -p
     ```
 
@@ -833,19 +834,19 @@ References: https://www.commandlinux.com/man-page/man8/ss.8.html
 ### Query or control network driver and hardware settings
 
 * Display ring buffer for a device (e.g. **eth0**)
-  * ```
+    ```
     ethtool -g eth0
     ```
 * Display driver information for a device (e.g. **eth0**)
-  * ```
+    ```
     ethtool -i eth0
     ```
 * Identify eth0 by sight, e.g. by causing LEDs to blink on the network port
-  * ```
+    ```
     ethtool -p eth0
     ```
 * Display network and driver statistics for a device (e.g. **eth0**)
-  * ```
+    ```
     ethtool -S eth0
     ```
 
@@ -866,21 +867,21 @@ cat /sys/class/net/<ethernet_device>/carrier
 ### Add IP address to hardware port (ethernet)
 
 * Find ethernet port ID on both computers
-  * ```
+    ```
     ip a
     ```
 * Add IP address (DHCO or static)
   * Computer 1
-    * ```
+      ```
       ip addr add <Private_IP_Address_1>/24 dev <ethernet_interface_1>
       ```
   * Computer 2
-    * ```
+      ```
       ip addr add <Private_IP_Address_2>/24 dev <ethernet_interface_2>
       ```
 
 * [Ping](#test-the-network-connectivity-of-a-domain-or-an-ip-address-with-ping) the address to confirm connection
-  * ```
+    ```
     ping <Private_IP_Address>
     ```
 
@@ -918,11 +919,11 @@ You can use the following template when you set an IP address manually:
 You can use the following template to add arguments when running a script:
 
 * Option 1
-  * ```
+    ```
     ./example_script.sh arg1 arg2
     ```
 * Option 2
-  * ```
+    ```
     sh example_script.sh "arg1" "arg2"
     ```
 
@@ -930,16 +931,16 @@ You can use the following template to add arguments when running a script:
 
 * Write a script
   * File: `example_script.sh`
-  * ```bash
+    ```bash
     #!/bin/sh
     echo $@
     ```
 * Give permissions
-  * ```bash
+    ```bash
     chmod +x ./example_script.sh
     ```
 * Run the script with arguments
-  * ```bash
+    ```bash
     sh example_script.sh arg1 arg2
     ```
 
@@ -947,7 +948,7 @@ You can use the following template to add arguments when running a script:
 ### Iterate over arguments
 
 * Write the script
-  * ```bash
+    ```bash
       # iterate_script.sh
       #!/bin/bash 
       for i; do 
@@ -955,16 +956,16 @@ You can use the following template to add arguments when running a script:
       done
     ```
 * Give permissions
-  * ```
+    ```
     chmod +x ./iterate_script.sh
     ```
 * Run the script with arguments
-  * ```
+    ```
     sh iterate_script.sh arg1 arg2
     ```
 
 * The following script is equivalent
-  * ```bash
+    ```bash
       # iterate_script.sh
       #/bin/bash 
       for i in $*; do 
@@ -977,7 +978,7 @@ You can use the following template to add arguments when running a script:
 ### Count lines in files given as arguments
 
 * Write the script
-  * ```bash
+    ```bash
     # count_lines.sh
     #!/bin/bash
      for i in $*; do
@@ -986,11 +987,11 @@ You can use the following template to add arguments when running a script:
     done
     ```
 * Give permissions
-  * ```
+    ```
     chmod +x ./count_lines.sh
     ```
 * Run the script with arguments (files). Here we use the script itself as an example.
-  * ```
+    ```
     sh count_lines.sh count_lines.sh
     ```
 
@@ -999,14 +1000,14 @@ You can use the following template to add arguments when running a script:
 ### Find path of a file
 
 * Write the script
-  * ```bash
+    ```bash
     # find.sh
     #!/bin/bash
 
     find / -iname $1 2> /dev/null
     ```
 * Run the script
-  * ```
+    ```
     sh find.sh <filename>
     ```
 
@@ -1015,13 +1016,13 @@ You can use the following template to add arguments when running a script:
 ### Print how many arguments are passed in a script
 
 * Write the script
-  * ```bash
+    ```bash
     # print_qty_args.sh
     #!/bin/bash
     echo This script was passed $# arguments
     ```
 * Run the script
-  * ```
+    ```
     sh print_qty_args.sh <filename>
     ```
 
@@ -1050,7 +1051,7 @@ Note that the Terraform documentation also covers other methods to install Terra
 
 * Option 1:
   * Use the following command line:
-    * ```
+      ```
       systemsetup -setremotelogin on
       ```
 * Option 2
@@ -1063,7 +1064,7 @@ Note that the Terraform documentation also covers other methods to install Terra
 
 * Open **Finder** \> **Go** \> **Go to Folder**
 * Paste this path
-  * ```
+    ```
     ~/Library/Caches
     ```
 
@@ -1087,15 +1088,15 @@ To install Chocolatey on Windows, we follow the [official Chocolatey website](ht
 
 * Run PowerShell as Administrator
 * Check if **Get-ExecutionPolicy** is restricted
-  * ```
+    ```
     Get-ExecutionPolicy
     ```
   * If it is restricted, run the following command:
-    * ```
+      ```
       Set-ExecutionPolicy AllSigned
       ```
 * Install Chocolatey
-  * ```
+    ```
     Set-ExecutionPolicy Bypass -Scope Process -Force; [System.Net.ServicePointManager]::SecurityProtocol = [System.Net.ServicePointManager]::SecurityProtocol -bor 3072; iex ((New-Object System.Net.WebClient).DownloadString('https://community.chocolatey.org/install.ps1'))
     ```
 * Note: You might need to restart PowerShell to use Chocolatey
@@ -1107,7 +1108,7 @@ To install Chocolatey on Windows, we follow the [official Chocolatey website](ht
 Once you've installed Chocolatey on Windows, installing Terraform is as simple as can be:
 
 * Install Terraform with Chocolatey
-  * ```
+    ```
     choco install terraform
     ```