CentOS Commands Cheat Sheet
If you're just getting started with CentOS, learning the commands and tools is a big help in increasing your productivity. In this blog, we go over some of the most useful CentOS commands and tools as chosen by our enterprise architects, then provide a list of common commands.
Most Useful CentOS Commands and Tools
There are lots of commands when it comes to CentOS and any tool that saves time and provides utility is a welcome addition to any person’s tool kit.
We asked several of our enterprise architects on the team what their favorite tools and commands were and here are some of the results:
The command top displays a list of processes or threads currently being used by the system kernel. This is useful for telling if something is holding up your systems resources. Summary is the first portion you’ll see followed by the fields and columns header and then the task area. You would use this to determine if a process is hung or hogging all the resources of your system prior to simply killing a pid at random.
Have you ever wondered from a networking perspective, what ports were open on various nodes of your network? Nmap allows you to quickly scan networks for open ports, application version information, running services, what operating system and version, what type of packet filters and firewalls are in use, and plenty of other useful and sensitive information. By listing information such as what ports are open, you can then seal the gaps in your security plan by closing those ports if possible. Nmap is a robust tool and the man pages are a highly recommended read to understand all the options and features available.
3. rpm -ql <packagename> or dpkg -L <packagename>
Have you ever wondered the easiest way to find all the files associated with a particular package? These two commands will show all the files and their location of the package named. Rpm is for RHEL/CentOS and dpkg is for Debian based systems.
One of the commands we frequently have our customers run during break/fix issues is sosreport. It creates an archive of config and diagnostic data from the system to be used for debugging and troubleshooting later. Can be used with xsos, a tool used to read the reports generated by sosreport.
This command arranges and formats the output of modules in /proc/modules and any kernel modules that are currently loaded.
An incredibly useful tool that allows you to examine the content of packets on a network interface matching a Boolean expression. This includes such information as handshakes between two devices, logins to sites, server traffic, UDP traffic, requests to printers, but more importantly it can detect traffic going to sketchy destinations or from unknown sources. Has a GUI version known as Wireshark.
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See the Top CentOS Alternatives
With CentOS 7 left as the only community-supported CentOS version, many teams are looking for their next Enterprise Linux distribution. In our 2022 Decision Maker's Guide to Enterprise Linux, our experts look at the top distributions available today, and which ones will provide the most stable and dependable experience going forward.
Commonly-Used CentOS Commands
While our list above is useful, there are many more commonly-used CentOS commands for Linux that you should keep close by. Here are some that make working from the command line a lot easier.
lists the contents of the directory
copies a file
moves a directory
moves up one directory
moves to home directory
lists the contents of the directory length-wise
present working directory
search given directory for namestring and display it
creates an alias
updates user authentication
adds a new user
shows currently logged on users
create new group
print system info
change permissions of a file
change the ownership of a file
compare the ownership of a file
compare two files against each other
displays disk usage of a directory
search set of database files and display result as standard output
repeatedly overwrite special patterns onto to-be-destroyed files
update and query run level info for system services
displays real-time system stats
disk partioning utility
mounts a filesystem
search named input files for lines containing match to given pattern, then print
configure networking interface
manually take down an interface
shows bandwidth usage of interface
brings interface back up
terminate a running process
list of currently running processes and their process IDs
manual page for particular command/tool
may be used to introspect and control the state of the "systemd" system and service manager
used to output last part of a file, useful on log files
Download Our CentOS Commands Cheat Sheet
Want a one-page PDF version of the shortcuts above? Click the link below to download the cheat sheet!Back to top
In conclusion, CentOS is filled with tons of tools and utilities, the aforementioned are just among some of the many available. www.man7.org has manual pages for these, and many more commands and all the usable options that go along with them.
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- How to Upgrade CentOS
- Enterprise Linux Datasheet
- The Long-Term Outlook for CentOS 7 Support
- Guide to CentOS
- Decision Maker's Guide to Enterprise Linux
- CentOS 8 Support and Services
- CentOS 7 Support and Services
- CentOS 6 Support and Services