# Linux and SSH
- [RHEL](#rhel)
- [VIM](#vim)
- [Neovim](#neovim)
- [SSH](#ssh)
- [OpenSSL](#openssl)
- [Linux Blogs](#linux-blogs)
- [Spanish Linux Blogs](#spanish-linux-blogs)
- [Youtube](#youtube)
- [Reddit](#reddit)
- [Linux Commands and Tools](#linux-commands-and-tools)
- [Bash](#bash)
- [Zsh](#zsh)
- [ZX](#zx)
- [Linux processes](#linux-processes)
- [Linux Memory](#linux-memory)
- [Linux and Kubernetes](#linux-and-kubernetes)
- [Systemd](#systemd)
- [Blogs](#blogs)
- [CommandLineFu](#commandlinefu)
- [Wait until Your Dockerized Database Is Ready before Continuing](#wait-until-your-dockerized-database-is-ready-before-continuing)
- [Copr Build System](#copr-build-system)
- [Pulp](#pulp)
- [Hashicorp](#hashicorp)
- [Linux Libraries](#linux-libraries)
- [Linux Networking](#linux-networking)
## RHEL
- [infoworld.com: Red Hatโs crime against CentOS](https://www.infoworld.com/article/3601202/red-hats-crime-against-centos.html) In the beginning, no one expected to get Red Hat Enterprise Linux for free. The end of CentOS as a free drop-in replacement is no cause for outrage.
- [arstechnica.com: CentOS is goneโbut RHEL is now free for up to 16 production servers](https://arstechnica.com/gadgets/2021/01/centos-is-gone-but-rhel-is-now-free-for-up-to-16-production-servers/) RHEL is now free for dev teams, and it's even free in production for up to 16 systems.
- [cyberciti.biz: Red Hat introduces new no-cost RHEL option](https://www.cyberciti.biz/linux-news/red-hat-introduces-new-no-cost-rhel-option/)
- [zdnet.com: Red Hat introduces free RHEL for small production workloads and development teams](https://www.zdnet.com/google-amp/article/red-hat-introduces-free-rhel-for-small-production-workloads-development-teams/) In response to complaints about Red Hat's latest plans for CentOS Linux, Red Hat will start offering no-cost Red Hat Enterprise Linux for small production workloads and customer development teams.
- [enterpriseai.news: Red Hatโs Disruption of CentOS Unleashes Storm of Dissent](https://www.enterpriseai.news/2021/01/22/red-hats-disruption-of-centos-unleashes-storm-of-dissent/)
- [arstechnica.com: Why Red Hat killed CentOSโa CentOS board member speaks](https://arstechnica.com/gadgets/2021/01/on-the-death-of-centos-red-hat-liaison-brian-exelbierd-speaks/) "The CentOS Board doesn't get to decide what Red Hat engineering teams do."
- [zdnet.com: Red Hat introduces free RHEL for open-source, non-profit organizations](https://www.zdnet.com/article/free-red-hat-enterprise-linux-for-open-source-non-profit-organizations/) Some CentOS users still aren't happy, but Red Hat is keeping its promise to open-source organizations that they'll have access to a free version of RHEL.
## VIM
- [VimWiki](https://github.com/vimwiki/vimwiki)
- [redhat.com: Vim: Basic and intermediate commands](https://www.redhat.com/sysadmin/vim-commands)
- [dev.to: Another one short Vim cheat sheet](https://dev.to/gleb_the_human/another-one-short-vim-cheat-sheet-39fc)
- [thevaluable.dev: A Vim Guide for Advanced Users](https://thevaluable.dev/vim-advanced/)
## Neovim
- [neovim](https://neovim.io/) hyperextensible Vim-based text editor
## SSH
- [gravitational.com: How to SSH Properly ๐](https://gravitational.com/blog/how-to-ssh-properly/)
- [19 Common SSH Commands In Linux With Examples](https://phoenixnap.com/kb/linux-ssh-commands)
- [commandlinefu.com/commands/matching/ssh](https://www.commandlinefu.com/commands/matching/ssh/c3No/sort-by-votes)
- [Auto-SSH for Linux security](https://github.com/mohanad86/secure-ssh-python)
- [Grant-Revoke-ssh-access](https://github.com/suraksha-123/Grant-Revoke-ssh-access) To automate the process of granting ssh access to a group of servers instances
- [How to use SSH properly and what is SSH Agent Forwarding](https://dev.to/levivm/how-to-use-ssh-and-ssh-agent-forwarding-more-secure-ssh-2c32)
- [How To Set up SSH Keys on a Linux / Unix System](https://www.cyberciti.biz/faq/how-to-set-up-ssh-keys-on-linux-unix/)
- [opensource.com: Bypass your Linux firewall with SSH over HTTP](https://opensource.com/article/20/7/linux-shellhub) Remote work is here to stay; use this helpful open source solution to quickly connect and access all your devices from anywhere.
- [Tรบneles SSH](https://www.atareao.es/ubuntu/tuneles-ssh)
- [paepper.com: How to properly manage ssh keys for server access](https://www.paepper.com/blog/posts/how-to-properly-manage-ssh-keys-for-server-access/)
- [goteleport.com: SSH Certificates Security. SSH Access Hardening ๐](https://goteleport.com/blog/ssh-certificates/)
- [dev.to: How to Manage Multiple SSH Key Pairs](https://dev.to/josephmidura/how-to-manage-multiple-ssh-key-pairs-1ik)
- [cyberciti.biz: Top 20 OpenSSH Server Best Security Practices](https://www.cyberciti.biz/tips/linux-unix-bsd-openssh-server-best-practices.html)
## OpenSSL
- [redhat.com: 6 OpenSSL command options that every sysadmin should know](https://www.redhat.com/sysadmin/6-openssl-commands) Look beyond generating certificate signing requests and see how OpenSSL commands can display practical information about certificates.
- [tecmint.com: Testssl.sh โ Testing TLS/SSL Encryption Anywhere on Any Port](https://www.tecmint.com/testssl-sh-test-tls-ssl-encryption-in-linux-commandline/)
## Linux Blogs
- [The Linux Foundation](http://www.linuxfoundation.org/)
- [tecmint.com ๐](https://www.tecmint.com/)
- [nixCraft ๐](https://www.cyberciti.biz/)
- [unixmen.com ๐](https://unixmen.com/)
- [opensource.com ๐](https://opensource.com/)
- [linux.com ๐](https://www.linux.com/)
- [linoxide.com ๐](https://linoxide.com/)
- [linuxjourney.com](https://linuxjourney.com/)
- [howtoforge.com](https://www.howtoforge.com/)
- [tecadmin.net](https://tecadmin.net/)
- [systemcodegeeks.com](https://www.systemcodegeeks.com/)
- [linuxnix.com](https://www.linuxnix.com/)
- [learnitguide.net](https://www.learnitguide.net/)
- [FOSS Force](http://fossforce.com/)
- [linuxhomenetworking.com](http://www.linuxhomenetworking.com/)
- [linuxtoday.com](http://www.linuxtoday.com/)
- [unixetc.co.uk](http://unixetc.co.uk/)
- [LWN.net](http://lwn.net/)
- [Linux-tutorial.info](http://www.linux-tutorial.info/)
- [The Lone Sysadmin](https://lonesysadmin.net/)
- [LinuxLinks.com](http://www.linuxlinks.com)
- [unixmages.com](http://unixmages.com)
- [The Geek Stuff](http://www.thegeekstuff.com/)
## Spanish Linux Blogs
- [systemadmin.es](http://systemadmin.es/)
- [muylinux.com](http://www.muylinux.com/)
- [linuxadictos.com](http://www.linuxadictos.com)
## Youtube
- [Linux Skills](https://www.youtube.com/channel/UCu2eNnWy-zc1xt_shCXQQfA)
- [CLImagic](https://www.youtube.com/user/climagic)
## Reddit
- [reddit.com/r/linuxadmin](https://www.reddit.com/r/linuxadmin/) Expanding Linux SysAdmin knowledge
## Linux Commands and Tools
- [**watchman command**: A File and Directory Watching Tool for Changes](https://www.tecmint.com/watchman-monitor-file-changes-in-linux/)
- [**ip command**: How to use IP Command in Linux with Examples](https://linoxide.com/linux-command/use-ip-command-linux/)
- [**curl command**: Understanding the Hidden Powers of curl](https://nordicapis.com/understanding-the-hidden-powers-of-curl/)
- [How To Use grep Command In Linux / UNIX ๐](https://www.cyberciti.biz/faq/howto-use-grep-command-in-linux-unix/)
- [tecmint.com: vtop โ A Linux Process and Memory Activity Monitoring Tool](https://www.tecmint.com/vtop-monitor-linux-process-usage/)
- [tecmint.com: How to Install htop on CentOS 8](https://www.tecmint.com/install-htop-on-centos-8/)
- [cyberciti.biz: bpytop โ Awesome Linux, macOS and FreeBSD resource monitor](https://www.cyberciti.biz/open-source/command-line-hacks/bpytop-awesome-linux-macos-and-freebsd-resource-monitor/)
- [redhat.com: Save time at the command line with HTTPie instead of curl](https://www.redhat.com/sysadmin/curl-hack-httpie) Automate testing endpoints, downloading files, and submitting forms with HTTPie.
- [redhat.com: World domination with cgroups part 8: down and dirty with cgroup v2](https://www.redhat.com/en/blog/world-domination-cgroups-part-8-down-and-dirty-cgroup-v2)
- [freecodecamp.org: RSync Examples โ Rsync Options and How to Copy Files Over SSH](https://www.freecodecamp.org/news/rsync-examples-rsync-options-and-how-to-copy-files-over-ssh/)
- [tecmint.com: How to Control Systemd Services on Remote Linux Server](https://www.tecmint.com/control-systemd-services-on-remote-linux-server/)
- [redhat.com: Vim: Basic and intermediate commands](https://www.redhat.com/sysadmin/vim-commands)
- [redhat.com: Using ssh-keygen and sharing for key-based authentication in Linux](https://www.redhat.com/sysadmin/configure-ssh-keygen) SSH key-based authentication is helpful for both security and convenience. See how to generate and share keys.
- [tecmint.com: How to Run Commands from Standard Input Using Tee and Xargs in Linux](https://www.tecmint.com/run-commands-from-standard-input-using-tee-and-xargs-in-linux/)
- [cyberciti.biz: How to configure pfSense as multi wan (DUAL WAN) load balance failover router](https://www.cyberciti.biz/faq/howto-configure-dual-wan-load-balance-failover-pfsense-router/)
- [nikhilism.com: Mystery Knowledge and Useful Tools](https://nikhilism.com/post/2020/mystery-knowledge-useful-tools/)
- [developers.redhat.com: Linux commands for developers](https://developers.redhat.com/cheat-sheets/linux-commands-cheat-sheet)
- [cyberciti.biz: BASH Shell Change The Color of Shell Prompt on Linux or UNIX](https://www.cyberciti.biz/faq/bash-shell-change-the-color-of-my-shell-prompt-under-linux-or-unix/)
- [cyberciti.biz: How to check TLS/SSL certificate expiration date from command-line](https://www.cyberciti.biz/faq/find-check-tls-ssl-certificate-expiry-date-from-linux-unix/)
- [igoroseledko.com: Parallel Rsync](https://www.igoroseledko.com/parallel-rsync/)
- [redhat.com: How to record your Linux terminal using asciinema](https://www.redhat.com/sysadmin/using-asciinema) Asciinema might be the application you've been looking for to demonstrate a skill or process that you want your colleagues or students to learn on-demand.
- [redhat.com: 5 advanced rsync tips for Linux sysadmins](https://www.redhat.com/sysadmin/5-rsync-tips) Use rsync compression and checksums to better manage file synchronization.
- [metacpan.org: a2p - Awk to Perl translator](https://metacpan.org/pod/App::a2p) A2p takes an awk script specified on the command line (or from standard input) and produces a comparable perl script on the standard output.
- [redhat.com: 5 questions to ask during your next sysadmin interview](https://www.redhat.com/sysadmin/5-questions-interview)
- [oilshell: Alternative shells](https://github.com/oilshell/oil/wiki/Alternative-Shells)
- [Timezone Bullshit](https://blog.wesleyac.com/posts/timezone-bullshit)
- [cyberciti.biz: How to check memory utilization in Linux](https://www.cyberciti.biz/faq/how-to-check-memory-utilization-in-linux/)
- [tecmint.com: Different Ways to Use Column Command in Linux](https://www.tecmint.com/linux-column-command/)
- [opensource.com: How to use the Linux grep command](https://opensource.com/article/21/3/grep-cheat-sheet)
- [dnschecker.org ๐](https://dnschecker.org/)
- [tecmint.com: 10 Useful Commands to Collect System and Hardware Information in Linux](https://www.tecmint.com/commands-to-collect-system-and-hardware-information-in-linux)
- [cyberciti.biz: How To Find Largest Top 10 Files and Directories On Linux / UNIX / BSD](https://www.cyberciti.biz/faq/how-do-i-find-the-largest-filesdirectories-on-a-linuxunixbsd-filesystem/)
- [cyberciti.biz: How to restart systemd without rebooting Linux when critical libraries installed](https://www.cyberciti.biz/faq/how-to-restart-systemd-without-rebooting-linux-when-critical-libraries-installed/)
- [cyberciti.biz: How to install ncdu on Linux / Unix to see disk usage](https://www.cyberciti.biz/open-source/install-ncdu-on-linux-unix-ncurses-disk-usage/)
- [cyberciti.biz: 21 Examples To Make Sure Unix / Linux Configuration Files Are Free From Syntax Errors](https://www.cyberciti.biz/tips/check-unix-linux-configuration-file-for-syntax-errors.html)
- [opensource.com: Don't love diff? Use Meld instead](https://opensource.com/article/20/3/meld) Meld is a visual diff tool that makes it easier to compare and merge changes in files, directories, Git repos, and more.
- [kalilinuxtutorials.com: Ldsview : Offline search tool for LDAP directory dumps in LDIF format](https://kalilinuxtutorials.com/ldsview/)
- [medium: Useful Commands/Solutions](https://medium.com/cloud-techies/useful-commands-solutions-49f1c1b4e033)
- [CLImagic subscription](https://www.patreon.com/climagic)
- [cyberciti.biz: How to save terminal output to a file under Linux/Unix](https://www.cyberciti.biz/faq/how-to-save-terminal-output-to-a-file-under-linux-unix/)
- [cyberciti.biz: ls* Commands Are Even More Useful Than You May Have Thought](https://www.cyberciti.biz/open-source/command-line-hacks/linux-ls-commands-examples/)
- [linuxtechlab.com: Search a file in Linux using Find & Locate command](https://linuxtechlab.com/search-a-file-in-linux-using-find-locate-command/)
- [tecmint.com: How to Install and Configure โCollectdโ and โCollectd-Webโ to Monitor Server Resources in Linux](https://www.tecmint.com/install-collectd-and-collectd-web-to-monitor-server-resources-in-linux/)
- [sysadminxpert.com: How to watch real time TCP and UDP ports on Linux (netstat & ss) ๐](https://sysadminxpert.com/how-to-watch-real-time-tcp-and-udp-ports-on-linux/)
- [cyberciti.biz: How to flush Redis cache and delete everything using the CLI](https://www.cyberciti.biz/faq/how-to-flush-redis-cache-and-delete-everything-using-the-cli/)
- [cyberciti.biz: How To: Linux Find Large Files in a Directory](https://www.cyberciti.biz/faq/find-large-files-linux/)
## Bash
- [igoroseledko.com: Checking Multiple Variables in Bash](https://www.igoroseledko.com/checking-multiple-variables-in-bash/)
- [Introduction to Bash Scripting Interactive training](https://ebook.bobby.sh/training.html)
- [dev.to: Introduction to Bash Scripting - A DO Hackathon Submission](https://dev.to/bobbyiliev/introduction-to-bash-scripting-5571)
- [datafix.com.au: BASHing data - Data ops on the Linux command line ๐](https://datafix.com.au/BASHing/)
- [medium: How to trigger an action at the end of the Shell/Bash script](https://medium.com/bash-tips-and-tricks/how-to-trigger-an-action-at-the-end-of-the-shell-bash-script-52b0ba9c157e) Using Bash/Shell trap, a built-in command to define any action to be executed before exiting the Bash or Shell script. You can define multiple actions and per signal.
- [redhat.com: Bash scripting: How to read data from text files](https://www.redhat.com/sysadmin/data-text-files) Here's how to extract data from a text file such as reading in a list of servers to test connectivity to them.
- [pement.org: Over 100 sed one-liners](http://www.pement.org/sed/sed1line.txt)
- [github: Safe ways to do things in bash](https://github.com/anordal/shellharden/blob/master/how_to_do_things_safely_in_bash.md)
- [rexegg.com: Regex Syntax Tricks](https://rexegg.com/regex-tricks.html)
- [pement.org: Handy one-line scripts for AWK](http://www.pement.org/awk/awk1line.txt)
- [flowfactor.be: Unit testing bash scripts the cloud-native way](https://www.flowfactor.be/2021/03/23/unit-testing-bash-scripts-the-cloud-native-way/)
- [robertmuth.blogspot.com: Better Bash Scripting in 15 Minutes](http://robertmuth.blogspot.com/2012/08/better-bash-scripting-in-15-minutes.html)
## Zsh
- [Oh My Zsh](https://ohmyz.sh/) Oh My Zsh is a delightful, open source, community-driven framework for managing your Zsh configuration. It comes bundled with thousands of helpful functions, helpers, plugins, themes, and a few things that make you shout...
- [zshdb.readthedocs.io](https://zshdb.readthedocs.io) zshdb - a gdb-like debugger for zsh
## ZX
- [zx](https://github.com/google/zx) A tool for writing better scripts
## Linux processes
- [percona.com: How Much Memory Does the Process Really Take on Linux? ๐](https://www.percona.com/blog/2020/09/11/how-much-memory-does-the-process-really-take-on-linux/)
## Linux Memory
- [learnsteps.com: Difference between minor page faults vs major page faults](https://www.learnsteps.com/difference-between-minor-page-faults-vs-major-page-faults/)
## Linux and Kubernetes
- [How Linux PID namespaces work with containers ๐](https://www.redhat.com/sysadmin/linux-pid-namespaces)
### Systemd
- [Start using systemd as a troubleshooting tool](https://opensource.com/article/20/5/systemd-troubleshooting-tool) While systemd is not really a troubleshooting tool, the information in its output points the way toward solving problems.
### Blogs
- [climagic.org](http://www.climagic.org)
- [Linux 101 Hacks](http://linux.101hacks.com/)
- [linuxjourney.com commandline](https://linuxjourney.com/lesson/the-shell#)
- [The Art of Command Line](https://github.com/jlevy/the-art-of-command-line)
### CommandLineFu
- [CommandLineFu ๐](https://www.commandlinefu.com)
- [twitter.com/commandlinefu](https://twitter.com/commandlinefu) Command line diamonds, created and voted on by our members
- [twitter.com/commandlinefu3](https://twitter.com/commandlinefu3) 3-star commands, a Linux afficionado's wet dream
- [twitter.com/commandlinefu10](https://twitter.com/commandlinefu10) 10 star command line gems - known to make experienced sysadmins weep with joy.
### Wait until Your Dockerized Database Is Ready before Continuing
- [Wait until Your Dockerized Database Is Ready before Continuing](https://nickjanetakis.com/blog/wait-until-your-dockerized-database-is-ready-before-continuing) A zero dependency Bash script that waits until a command of your choosing has run successfully
- [github.com/nickjj/wait-until](https://github.com/nickjj/wait-until)
### Copr Build System
- Building a repo with RPM packages from PyPI is super easy using Copr.
- [copr.fedorainfracloud.org](https://copr.fedorainfracloud.org/) Copr is an easy-to-use automatic build system providing a package repository as its output.
- [Copr](https://pagure.io/copr/copr)
### Pulp
- [pulpproject.org](https://pulpproject.org/) Fetch, Upload, Organize, and Distribute Software Packages.
### Hashicorp
- [Announcing the HashiCorp Linux Repository](https://www.hashicorp.com/blog/announcing-the-hashicorp-linux-repository)
## Linux Libraries
- [How to handle dynamic and static libraries in Linux](https://opensource.com/article/20/6/linux-libraries)
## Linux Networking
- [ntop](http://www.ntop.org/)
- [ngrep](http://ngrep.sourceforge.net/)
- [Angry IP Scanner (or simply ipscan)](http://angryip.org/) to Nmap and cross-platform
- [cyberciti.biz - ss: Display Linux TCP / UDP Network and Socket Information](http://www.cyberciti.biz/tips/linux-investigate-sockets-network-connections.html)
- [cyberciti.biz - SS Utility: Quick Intro](http://www.cyberciti.biz/files/ss.html)
- [binarytides.com - 10 examples of Linux ss command to monitor network connections](http://www.binarytides.com/linux-ss-command/)
- [unix.stackexchange.com: ss - linux socket statistics utility output format](http://unix.stackexchange.com/questions/252744/ss-linux-socket-statistics-utility-output-format)
- [stackoverflow.com: difference between netstat and ss in linux?](http://stackoverflow.com/questions/11763376/difference-between-netstat-and-ss-in-linux)
- [lintut.com: Monitoring network connection using ss command](http://lintut.com/monitoring-network-connection-using-ss-command/)
- [Linux networking examples and tutorials for advanced users](https://github.com/knorrie/network-examples) Includes lab examples for lxc, bgp, vpn, & more
- [blog.pandorafms.org: Useful Network commands](https://blog.pandorafms.org/network-commands/) VNStat, ping, traceroute, ping, arp, curl and wget, netstat, whois, ssh, tcpdump, ngrep, nmap, netcat, lsof, iptraf
- [Diferencias entre servidor proxy y servidor proxy inverso](https://www.redeszone.net/tutoriales/servidores/diferencias-proxy-vs-proxy-inverso/)
- [cyberciti.biz: Linux ip Command Examples ๐](https://www.cyberciti.biz/faq/linux-ip-command-examples-usage-syntax/)
- [cyberciti.biz: Linux: 25 Iptables Netfilter Firewall Examples For New SysAdmins](https://www.cyberciti.biz/tips/linux-iptables-examples.html)
- [redhat.com: 6 tcpdump network traffic filter options](https://www.redhat.com/sysadmin/tcpdump-part-one) The first six of eighteen common tcpdump options that you should use for network troubleshooting and analysis.
---
[](https://github.com/jlevy/the-art-of-command-line)