24 KiB
CLI and Scripts Basics
Table of Contents
- Introduction
- Basic Commands
- Update and upgrade packages
- Test the network connectivity of a domain or an IP address with ping
- Install Go
- Install Brew
- Brew basic commands
- Install Terraform with Brew
- Yarn basic commands
- Set default terminal
- See the current path
- List hidden files
- Display the content of a directory
- Vim modes and basic commands
- Check the listening ports using netstat
- See the disk usage of different folders
- Verify the application version
- Find the path of a file with only the file name
- Become the superuser (su) on Linux
- Exit a session
- Know the current user
- See the path of a package
- Set the path of a package
- See the current path
- Find the current shell
- SSH into Remote Server
- Replace a string by another string in a text file
- Replace extensions of files in a folder
- Remove extension of files in a folder
- See the current date and time on Linux
- Special variables in Bash Shell
- Gather DNS information of a website
- Partition and mount a disk
- Encryption
- Network-related Commands
- Basic Scripts
- Linux
- MAC
- Windows
- References
Introduction
We present here a quick guide on different command-line interface (CLI) commands as well as some basic scripts.
The main goal of this guide is to demonstrate that having some core understanding of CLI and scripts can drastically increase efficiency and speed when it comes to deploying and managing workloads on the TFGrid.
Basic Commands
Update and upgrade packages
The command update ensures that you have access to the latest versions of packages available.
sudo apt update
The command upgrade downloads and installs the updates for each outdated package and dependency on your system.
sudo apt upgrade
Test the network connectivity of a domain or an IP address with ping
To test the network connectivity of a domain or an IP address, you can use ping
on Linux, MAC and Windows:
- Template
ping <IP-Address_Or_Domain>
- Example
ping threefold.io
On Windows, by default, the command will send 4 packets. On MAC and Linux, it will keep on sending packets, so you will need to press Ctrl-C
to stop the command from running.
You can also set a number of counts with -c
on Linux and MAC and -n
on Windows.
- Send a given number of packets on Linux and MAC (e.g 5 packets)
ping -c 5 threefold.io
- Send a given number of packets on Windows (e.g 5 packets)
ping -n 5 threefold.io
Install Go
Here are the steps to install Go.
- Install go
sudo apt install golang-go
- Verify that go is properly installed
go version
Install Brew
Follow those steps to install Brew
- 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 "$(/home/linuxbrew/.linuxbrew/bin/brew shellenv)"
- Verify the installation
brew doctor
Brew basic commands
- To update brew in general:
brew update
- To update a specific package:
brew update <package_name>
- To install a package:
brew install <package_name>
- To uninstall a package:
brew uninstall <package_name>
- To search a package:
brew search <package_name>
- Uninstall Brew
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/uninstall.sh)"
Install Terraform with Brew
Installing Terraform with Brew is very simple by following the Terraform documentation.
- Compile HashiCorp software on Homebrew's infrastructure
brew tap hashicorp/tap
- Install Terraform
brew install hashicorp/tap/terraform
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
Set default terminal
update-alternatives --config x-terminal-emulator
See the current path
pwd
List hidden files
ls -ld .?*
Display the content of a directory
You can use tree to display the files and organization of a directory:
- General command
tree
- View hidden files
tree -a
Vim modes and basic commands
Vim is a free and open-source, screen-based text editor program.
With Vim, you can use two modes.
- Insert mode - normal text editor
- Press i
- Command mode - commands to the editor
- Press ESC
Here are some basic commands:
- Delete characters
- x
- Undo last command
- u
- Undo the whole line
- U
- Go to the end of line
- A
- Save and exit
- :wq
- Discard all changes
- :q!
- Move cursor to the start of the line
- 0
- Delete the current word
- dw
- Delete the current line
- dd
Check the listening ports using netstat
Use the command:
netstat
See the disk usage of different folders
du -sh *
Verify the application version
which <application_name>
Find the path of a file with only the file name
On MAC and Linux, you can use coreutils and realpath from Brew:
brew install coreutils
realpath file_name
Become the superuser (su) on Linux
You can use either command:
- Option 1
sudo -i
- Option 2
sudo -s
Exit a session
You can use either command depending on your shell:
exit
logout
Know the current user
You can use the following command:
whoami
See the path of a package
To see the path of a package, you can use the following command:
whereis <package_name>
Set the path of a package
export PATH=$PATH:/snap/bin
See the current path
pwd
Find the current shell
- Compact version
echo $SHELL
- Detailed version
ls -l /proc/$$/exe
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>
*Note: For MAC, you can install openssh-server and openssh-client with Brew: brew install openssh-server and brew install openssh-client.
To enable remote login on a MAC, read this section.
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>
Replace extensions of files in a folder
Replace ext1 and ext2 by the extensions in question.
find ./ -depth -name "*.ext1" -exec sh -c 'mv "$1" "${1%.ext1}.ext2"' _ {} \;
Remove extension of files in a folder
Replace ext with the extension in question.
for file in *.ext; do
mv -- "$file" "${file%%.ext}"
done
See the current date and time on Linux
date
Special variables in Bash Shell
Special Variables | Descriptions |
---|---|
$0 | Name of the bash script |
$1, $2...$n | Bash script arguments |
|
Process id of the current shell |
$* | String containing every command-line argument |
$# | Total number of arguments passed to the script |
$@ | Value of all the arguments passed to the script |
$? | Exit status of the last executed command |
$! | Process id of the last executed command |
$- | Print current set of option in current shell |
Gather DNS information of a website
You can use Dig to gather DNS information of a website
- Template
dig <website.tld>
- Example
dig threefold.io
You can also use online tools such as DNS Checker.
Partition and mount a disk
We present one of many ways to partition and mount a disk.
- Create partition with gparted
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
Encryption
Encrypt files with Gocryptfs
You can use 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
- Option 1
Encrypt files with Veracrypt
To encrypt files, you can use Veracrypt. Let's see how to download and install Veracrypt.
- 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
- Download the package
- 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
- Download the package
You can visit Veracrypt download page to get the newest releases.
- To run Veracrypt
veracrypt
- Veracrypt documentation is very complete. To begin using the application, visit the Beginner's Tutorial.
Network-related Commands
See the network connections and ports
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>
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
- Template
- Delete an address
- Template
ip addr del
- Example: set IP address to device enp0
ip addr del 192.168.3.4/24 dev enp0
- Template
- 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
- Template
- 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
- Template
- 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
- Template
- 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
- Template
- 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
- Template
- 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
- Template
- 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
- Template
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
Note: You can combine parameters, e.g. ss -aeo.
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
References: https://man.archlinux.org/man/ethtool.8.en
See if ethernet port is active
Replace <ethernet_device> with the proper device:
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>
- Computer 1
-
Ping the address to confirm connection
ping <Private_IP_Address>
To set and view the address for either DHCP or static, go to Networks then Details.
Private IP address range
The private IP range is the following:
- 10.0.0.0–10.255.255.255
- 172.16.0.0–172.31.255.255
- 192.168.0.0–192.168.255.255
Set IP Address manually
You can use the following template when you set an IP address manually:
- Address
- <Private_IP_Address>
- Netmask
- 255.255.255.0
- Gateway
- optional
Basic Scripts
Run a script with arguments
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"
Print all arguments
- Write a script
- File:
example_script.sh
#!/bin/sh echo $@
- File:
- Give permissions
chmod +x ./example_script.sh
- Run the script with arguments
sh example_script.sh arg1 arg2
Iterate over arguments
-
Write the script
# iterate_script.sh #!/bin/bash for i; do echo $i done
-
Give permissions
chmod +x ./iterate_script.sh
-
Run the script with arguments
sh iterate_script.sh arg1 arg2
-
The following script is equivalent
# iterate_script.sh #/bin/bash for i in $*; do echo $i done
Count lines in files given as arguments
- Write the script
# count_lines.sh #!/bin/bash for i in $*; do nlines=$(wc -l < $i) echo "There are $nlines lines in $i" 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
Find path of a file
- Write the script
# find.sh #!/bin/bash find / -iname $1 2> /dev/null
- Run the script
sh find.sh <filename>
Print how many arguments are passed in a script
- Write the script
# print_qty_args.sh #!/bin/bash echo This script was passed $# arguments
- Run the script
sh print_qty_args.sh <filename>
Linux
Install Terraform
Here are the steps to install Terraform on Linux based on the Terraform documentation.
wget -O- https://apt.releases.hashicorp.com/gpg | sudo gpg --dearmor -o /usr/share/keyrings/hashicorp-archive-keyring.gpg
echo "deb [signed-by=/usr/share/keyrings/hashicorp-archive-keyring.gpg] https://apt.releases.hashicorp.com $(lsb_release -cs) main" | sudo tee /etc/apt/sources.list.d/hashicorp.list
sudo apt update && sudo apt install terraform
Note that the Terraform documentation also covers other methods to install Terraform on Linux.
MAC
Enable remote login on MAC
- Option 1:
- Use the following command line:
systemsetup -setremotelogin on
- Use the following command line:
- Option 2
- Use System Preferences
- Go to System Preferences -> Sharing -> Enable Remote Login.
Find Other storage on MAC
- Open Finder > Go > Go to Folder
- Paste this path
~/Library/Caches
Sort files by size and extension on MAC
- From your desktop, press Command-F.
- Click This Mac.
- Click the first dropdown menu field and select Other.
- From the Search Attributes window
- tick File Size and File Extension.
Windows
Install Chocolatey
To install Chocolatey on Windows, we follow the official Chocolatey website instructions.
- Run PowerShell as Administrator
- Check if Get-ExecutionPolicy is restricted
Get-ExecutionPolicy
- If it is restricted, run the following command:
Set-ExecutionPolicy AllSigned
- If it is restricted, run the following command:
- 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
Install Terraform with Chocolatey
Once you've installed Chocolatey on Windows, installing Terraform is as simple as can be:
- Install Terraform with Chocolatey
choco install terraform
Find the product key
Write the following in Command Prompt (run as administrator):
wmic path SoftwareLicensingService get OA3xOriginalProductKey
Find Windows license type
Write the following in Command Prompt:
slmgr /dli
References
- GNU Bash Manual - https://www.gnu.org/software/bash/manual/bash.html