When working with Red Hat CentOS, it’s essential to become familiar with the terminal and the wide range of commands that you can use to navigate, modify, and manage your Linux system. In this article, we’re going to explore some of the most useful commands that will aid your CentOS journey.
1. Basic File and Directory Commands
ls - List Directory Contents
This command is used to list the contents of a directory.
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ls
cd - Change Directory
To navigate through the Linux files and directories, use the cd command.
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cd /path/to/directory
pwd - Print Working Directory
If you want to know the absolute path of your current directory, pwd comes in handy.
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pwd
touch - Create a New File
Creating a new, empty file is as easy as typing touch followed by the file name.
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touch myfile.txt
rm - Remove a File or Directory
You can remove a file or directory using rm command. Use -r option for directories.
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rm myfile.txt
rm -r mydirectory
2. System Information Commands
uname - Print System Information
uname displays the important information about your system. The -a option prints all system information.
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uname -a
top - Monitor System, Process, and Users
top gives you real-time information about your system, the current processes, and users.
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top
df - Disk Space Usage of File Systems
df displays the amount of disk space used and available on Linux file systems.
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df -h
free - Memory Usage
This command gives you a summary of the memory usage in your system.
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free -m
3. Package Management with YUM
yum install - Install a Package
Use yum install followed by the package name to install a new package.
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sudo yum install packageName
yum remove - Remove a Package
To remove an installed package, use yum remove followed by the package name.
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sudo yum remove packageName
yum update - Update System Packages
To update all the system packages to their latest versions, just type yum update.
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sudo yum update
yum search - Search for a Package
If you need to find a package in the repositories, use yum search.
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yum search packageName
4. Network-related Commands
ping - Send ICMP ECHO_REQUEST to Network Hosts
You can check your connectivity to a network host using ping.
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ping host
ifconfig or ip - Display or Configure a Network Interface
Use ifconfig or ip to configure, control, and query TCP/IP network interface parameters.
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ifconfig
ip addr
netstat - Network Statistics
netstat provides a variety of information about network connections.
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netstat
ssh - OpenSSH Remote Login Client
ssh command is used for logging into a remote machine and for executing commands on a remote machine.
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ssh username@hostname
The above commands are just the tip of the iceberg when it comes to managing and navigating a CentOS system, but they’re a good starting point for both beginners and experienced users alike. Don’t hesitate to explore the man pages for any command you’re interested in, as it provides in-depth information about usage, options, and examples.
