How to Open Ports and List Open Ports in Linux

In Linux, you can access and edit text files using a text editor that is designed to work with plain text. These files are not specifically coded or formatted. Linux allows one to create a file in numerous ways. The fastest is, probably, Linux Command Line or Terminal. For all users—especially server administrators—who must rapidly generate text files, scripts, or configuration files for their work, this is a very important ability. Let's proceed to the guide on four standard techniques for creating a text file on the terminal. Prerequisites for File Creation in Linux Ensure these prerequisites are met before generating files in a Linux environment using the command-line interface: Access to a Functional Linux System: You must either have a Linux-based operating system installed on your computer or secure access to a Linux server via SSH (Secure Shell) protocol. Operational Terminal Interface: Confirm that your terminal application is accessible and fully operational. The terminal serves as your primary gateway to executing commands. Adequate User Permissions: Verify you can create files within the chosen directory. You may need to use sudo (for directories with access restrictions) to escalate privileges. Fundamental Commands Proficiency: You must get familiar with essential commands, such as touch for file creation, echo for printing text, cat for viewing file contents, and text editors like nano, vim, or vi for editing files directly. Text Editing Utilities: Ensure your system includes text editing tools: nano for command line simplicity, vim for advanced configurations, or graphical options like gedit for user-friendly navigation. Directory Management Expertise: Develop familiarity with directory navigation commands like cd for changing the working directory and ls for listing directory contents. This knowledge streamlines your workflow and avoids potential errors. Using the touch Command Generally, we use the touch command to create empty files and change timestamps. It will create an empty file if it doesn't exist already.  To create a text file in the current directory with the touch command: Open your terminal emulator. Type the command: touch filename.txt Change "filename" to your desired name. The timestamps for access and modification will be updated without changes in file content if the file exists already. Otherwise, an empty file is created with a given name.  Press Enter—if it is successful, there will be no output. Use the ls command to list the directory content and verify file creation. Using the echo Command Redirection The echo command is widely used to display text on the terminal. But its capabilities go beyond that; it may also be used to write content to a file or create an empty file. For this, combine the echo command with double redirect symbols (you can also use a single >) and the desired filename. A text file can be created by redirecting the output of the echo command to a file. See how it works: Open your terminal emulator. Type the command: echo “Your text content here” > filename.txt Replace the text in double quotations (do not delete them) with yours to add it to the file.  After you press Enter, your text will be added to the file filename.txt. It will overwrite an existing file, if there is one. Otherwise, it will just create a new one. Press Enter. To verify that the file has been created and contains the desired content, use cat command to display the content.  Using the cat Command Redirection In Linux, the cat command is mostly used to concatenate and show file contents. It can, however, also be used to generate a text document by redirecting the standard output of cat to a file. Open your terminal emulator. Type the following command: cat > filename.txt Replace filename.txt with the name for your text file. This command instructs cat to receive input rom the terminal and to redirect it into the filename.txt. Press Enter. The terminal will be waiting for input.  Enter the text you want in the file. Press Enter after each line. Press Ctrl + D when you are done. This signals the end of input to the cat and saves the content.  Run the cat command to check that the file has been created and contains the desired content. Start using Hostman efficient S3 storage Using printf for Advanced File Creation The printf utility is a powerful alternative to echo, offering enhanced formatting options for structuring text. It allows users to create files with precisely formatted content. Open the terminal. Use printf to define the text layout, incorporating formatting elements like newlines (\n) or tabs (\t). Redirect the output to a file using the > operator. Example: printf "First Line\nSecond Line\nIndented\tThird Line\n" >  formatted_file.txt Run the cat command to inspect the file's content and ensure the formatting matches expectations. Append Without Overwriting: To add content to an existing file without overwriting its current data, replace > with the append operator >>: printf "Additional content here.\n" >> formatted_file.txt Using a Text Dditor You can also create new files in linux text editors. There is always at least one integrated command-line text editor in your Linux distribution. But you can choose and install a different one according to your preferences, for example, Vim, Nano, or Emacs. Each of them has its own features and advantages. Vim vim, which stands for "Vi IMproved," is a very flexible and adaptable text editor. It is well-known for its modal editing, which allows for distinct modes for various functions like text entry, navigation, and editing. It allows split windows, multiple buffers, syntax highlighting, and a large selection of plugins for extra features. To create a text file using vim, follow the steps below: Open vim, with the desired filename as an argument. Press i to switch to Insert mode. Start typing and editing the filename.txt.  To save and exit, press Esc to ensure that command mode is running. Type: wq (write and quit) and press Enter. Nano nano is ideal for short adjustments and straightforward text files because it is lightweight and requires little setup. It provides support for basic text manipulation functions, search and replace, and syntax highlighting. To create a text file using nano, follow the steps below:  Run nano with the desired filename as an argument. It will open a new buffer for editing the file filename.txt. Start typing and editing the filename.txt.  To save and exit, press Ctrl + O to write the file, confirm the filename, and then press Ctrl + X to exit Nano. Emacs emacs is a powerful and flexible text editor that supports syntax highlighting, multiple buffers, split windows, and integration with external tools and programming languages. To create a text file using emacs, follow the steps below:  Open emacs, with the desired filename as an argument. Start typing and editing the filename.txt.  To save and exit, press Ctrl + X, followed by Ctrl + S to save the file, and then Ctrl + X, followed by Ctrl + C to exit Emacs. Note: If a message states that "VIM command not found", "nano command not found" or "emacs command not found" in Linux, it typically means that the vim, nano or emacs text editor is not installed on the system, or it's not included in the PATH environment variable, which is a list of directories where the operating system looks for executable files. To resolve this, install the text editor first using the command:  apt-get install vim apt-get install nano  apt-get install emacs Gedit An intuitive text editor that supports working with plain text and has syntax highlighting for programming languages. A straightforward graphical interface makes it usable for various tasks, from quick edits to complex document preparation. Open the Gedit Application: Launch Gedit either through the applications menu or by executing the following command in the terminal: gedit example.txt Gedit will create a new file if the specified one does not exist. Input Your Text: Type or paste your desired content into the editor. Save the File: Save your work with Ctrl + S or select File > Save. If creating a new file, specify a filename and a location. Verify: Return to the terminal and confirm the file exists with the ls command or review its content with cat. Linux File Creation Recommendations Ensure you have sufficient permissions to create files in the target directory. If they are insufficient, consider working in a directory where you have full rights (or elevate privileges with sudo). Check if a file with the identical name is already present before using the > operator, as the command will overwrite existing content. To prevent data loss, opt for the append operator >>. Familiarize yourself with the printf, echo, and text editors like vim or nano. These tools will help you reduce errors when working with files in Linux, as well as boost productivity. Use printf for creating files requiring structured content, such as configuration files or scripts with precise formatting needs. Conclusion Now you have acquainted yourself with the fundamental skill of creating a file in Linux using the terminal! Using the Linux command line, several fast and efficient methods exist to create and manage text files. Apply several techniques to meet a different requirement using the touch, echo, cat, printf commands, or text editors like vim, nano, gedit, or emacs. Users can select the method that sufficiently meets their requirements, such as creating empty files, appending text, or significantly modifying material. In summary, any of these methods enable Linux users to easily and quickly handle text files straight from the command line. Hostman offers a reliable managed Linux VPS for your projects.

Working with any IT project becomes much easier when the administrator has a wide range of metrics and monitoring data at their fingertips. It's even better when the data is presented in a clear and visual format. This is where tools like Grafana come in — an open-source solution designed to gather information from various sources and consolidate it into visual reports. Grafana supports multiple platforms — Windows, macOS, Linux (including popular distributions like Debian, Ubuntu, CentOS, Fedora, OpenSuse, or RedHat). It can work with databases such as SQLite, MySQL, and PostgreSQL. With so many options, administrators rarely need to adapt the solution to their environment. In this tutorial, we'll go over how to install Grafana, configure it, and work with dashboards. Installing Grafana on CentOS Stream When ordering a Linux VPS, users can install any Linux operating system. Usually, this is one of the common distributions like CentOS or Ubuntu. For this example, we'll assume the OS is already installed and ready for Grafana and other utility programs. Let's import the GPG keys: wget -q -O gpg.key https://rpm.grafana.com/gpg.key sudo rpm --import gpg.key Create a new official repository configuration: sudo nano /etc/yum.repos.d/grafana.repo Add the following content to the file: [grafana] name=grafana baseurl=https://rpm.grafana.com repo_gpgcheck=1 enabled=1 gpgcheck=1 gpgkey=https://rpm.grafana.com/gpg.key sslverify=1 sslcacert=/etc/pki/tls/certs/ca-bundle.crt Install the application: sudo dnf install grafana Enable autostart and launch Grafana: sudo systemctl enable grafana-server sudo systemctl start grafana-server Check the status to ensure Grafana is running: sudo systemctl status grafana-server You should see a message confirming that the service is loaded and active. This step is especially useful if someone previously worked with the server or installed a custom Linux build with bundled utilities. Installing Grafana on Ubuntu The process is similar: we install Grafana from the official repository after preparing the system to trust the source. Run these commands: wget -q -O - https://packages.grafana.com/gpg.key | sudo apt-key add - sudo add-apt-repository "deb https://packages.grafana.com/oss/deb stable main" sudo apt update sudo apt install grafana sudo systemctl enable grafana-server sudo systemctl start grafana-server sudo systemctl status grafana-server Firewall Configuration for Grafana By default, Grafana uses port 3000. Here's how to open it in different firewalls. For iptables: Add the rule: sudo iptables -A INPUT -p tcp --dport 3000 -m state --state NEW -j ACCEPT Save the rules so they persist after reboot: sudo service iptables save Restart iptables to apply changes: sudo systemctl restart iptables For firewalld: firewall-cmd --zone=public --add-port=3000/tcp --permanent systemctl reload firewalld Default Login and Password Grafana uses the default login/password: Username: admin Password: admin If forgotten, reset it with: grafana-cli admin reset-admin-password --homepath "/usr/share/grafana" new_password Data Sources and Plugin Installation Grafana supports numerous data sources: Prometheus, Graphite, OpenTSDB, InfluxDB, and more. It also allows plugin installations to enhance functionality. For example, to install the Zabbix plugin, run: grafana-cli plugins install alexanderzobnin-zabbix-app systemctl restart grafana-server After restart, go to Configuration > Plugins and find Zabbix. After you enable it, you can configure it under Data Sources. This same process applies to other plugins like Grafana PostgreSQL or Grafana Elasticsearch. Working with Grafana Dashboards The core of Grafana is dashboards — sets of panels that visually display data. Users can create their own dashboards by clicking New Dashboard and selecting panel types. Dashboard Types: Graph – multiple metrics in one panel. Stat – single metric graph. Gauge – speedometer-style display. Bar Gauge – vertical bar graph. Table – table with multiple metrics. Text – freeform text. Heatmap – heatmap display. Alert List – list of Grafana alerts. Dashboard List – list of favorite dashboards. You can also display logs from external sources using Grafana Logs, and export/import dashboards for reuse. For advanced control, refer to the official documentation. You can directly edit the grafana.ini file to change: Default ports Log storage paths Proxy settings User access controls Feature toggles Conclusion Grafana is a powerful and flexible monitoring solution. To fully unlock its potential, experiment with dashboards, try manual config via grafana.ini, and explore third-party plugins. As an actively developed project, Grafana remains one of the top data visualization and monitoring tools.

The SSH (Secure Shell) protocol is a network protocol for remote command-line management of operating systems, widely considered the standard for remote access to *nix machines. It allows secure login to a server, remote command execution, file management (creating, deleting, copying, etc.), and more. Most cloud and hosting providers require SSH to access their services. In this article, we’ll look at how to copy files over SSH on both Windows and Linux systems. How SSH Works SSH can securely transmit any data (audio, video, application protocol data) through an encrypted communication channel. Unlike outdated and insecure protocols like Telnet and rlogin, SSH ensures data confidentiality and authenticity — essential for internet communications. Here’s how a secure connection between a client and server is established: TCP Connection Setup: By default, the server listens on port 22. Both sides share a list of supported algorithms (compression, encryption, key exchange) and agree on which to use. Authentication: To prevent impersonation, both parties verify each other's identities using asymmetric encryption (public/private key pairs). First, the server is authenticated. On the first connection, the client sees a warning with server details. Trusted server keys are stored in /home/<username>/.ssh/known_hosts. Key Generation: Once the server is verified, both sides generate a symmetric key to encrypt all data exchanged. User Authentication: This is done using either a password or a client-sent public key stored in /home/<username>/.ssh/authorized_keys on the server. The most popular implementation on Linux is OpenSSH, which comes pre-installed on most distributions (Ubuntu, Debian, RHEL-based, etc.). Clients like PuTTY or MobaXterm are used on Windows. Since Windows 10 and Server 2019, OpenSSH tools are also available natively. You can learn more about working with SSH in our tutorial. File Copying via SSH Two main utilities for copying files over SSH in Linux are scp and sftp. Both come with OpenSSH. SSH supports two protocol versions: 1 and 2. OpenSSH supports both, but version 1 is rarely used. Autocompletion Setup To enable Tab-based autocompletion when using scp, set up public key authentication: Generate a key pair: ssh-keygen You’ll see output like: Generating public/private rsa key pair. Enter file in which to save the key (/home/user/.ssh/id_rsa): Enter passphrase (empty for no passphrase): By default, your keys (id_rsa for private and id_rsa.pub for public) are saved to ~/.ssh/. Now copy the public key to the remote machine: ssh-copy-id [username]@[ip-address] After entering the user's password, you’ll see a message confirming the key was added. Secure Copy (SCP) For small data transfers (e.g., service configs), scp is best. Copy from local to remote: scp test.txt user@192.168.1.29:/home/user/ Copy multiple files: scp test1.txt test2.txt user@192.168.1.29:/home/user/ Copy from remote to local: scp user@192.168.1.29:/home/user/test.txt ~/ Copy directories: scp -r testdir user@192.168.1.29:/home/user/ Remote-to-remote copy: scp gendo@192.168.1.25:/home/gendo/test.txt user@192.168.1.29:/home/user/ Secure FTP (SFTP) SFTP is another utility included in OpenSSH. As of OpenSSH 9.0, scp now uses SFTP by default instead of the old SCP/RCP protocol. Unlike classic FTP, sftp transmits encrypted data over a secure tunnel. It does not require a separate FTP server. Example usage: sftp misato@192.168.1.29 sftp> ls sftp> lcd testdir/ sftp> get test.txt sftp> bye Graphical file managers like Midnight Commander and Nautilus use sftp. In Nautilus, the remote server appears like a local folder, e.g., user@ip. Copying Files Over SSH on Windows Use the pscp command-line tool from PuTTY to copy files on Windows. Copy to server: pscp C:\server\test.txt misato@192.168.1.29:/home/misato/ Copy from server: pscp misato@192.168.1.29:/home/misato/test.txt C:\file.txt List files on remote server: pscp -ls user@192.168.1.29:/home/misato Use quotes for paths with spaces: pscp "C:\dir\bad file name.txt" misato@192.168.1.29:/home/misato/ To get help, run: pscp Conclusion We’ve covered how to copy files to and from a server using the secure SSH protocol. If you work with cloud servers, understanding SSH is essential — it’s the standard method for remote access to *nix machines and a vital part of everyday DevOps and system administration.