c0reysc0tt/.bashrc

## .bashrc

####################
#  CLI cheatsheet  #
####################

# cheatsheet directory location:
CHEATDIR=~/.cheatsheet

# Use 'vicheat' to edit the cheatsheet
alias vicheat='vim $CHEATDIR/command_cheatsheet'

# Use 'cheat <word>' to search for <word> in the cheatsheet
cheat() {
    grep -iw --color=auto $1 $CHEATDIR/command_cheatsheet
}

# OPTIONAL: Use 'thecheat <word>' to have cheatsheet results delivered in color by Homestar Runner's The Cheat.
# (Requires cowsay, lolcat, and thecheat.cow)
thecheat () {
    grep -iw $1 $CHEATDIR/command_cheatsheet | cowsay -f thecheat -n | lolcat
}


## README.md

      
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              README.md
            
          
    bash CLI cheatsheet

A reference tool for maintaining and searching a cheatsheet for bash commands

Summary:

I use this to quickly look up Linux commands I run frequently but don't want to remember or type.  It greps for whatever word you type after "cheat".  My cheatsheet file is included as a starting point, but feel free to modify it or use your own as you see fit.
Setup:


Copy these files to a local directory. For exaple:

mkdir ~/.cheatsheet && cd ~/.cheatsheet && git clone https://gist.github.com/c0reysc0tt/ccde4ffd1e5ff740569f5cd9700a4262 .

Copy the contents of of the included .bashrc snippet to your own .bashrc or .bash_profile. For example:

cat .bashrc >> ~/.bashrc && source ~/.bashrc
.bashrc notes:


Make sure the CHEATDIR variable matches the location where you cloned the repo.
If you plan to use your cheatsheet on multiple systems but don't want to use Git, consider putting it in a folder that autopmatically syncs with a cloud storage service like Dropbox or Google Drive.
The thecheat function is optional.  See below for additional dependencies and usage.

Usage:

Use cheat <word> to search the cheatsheet for a word.  Results will look like this:

To have your results delivered by a colorful ASCII version of The Cheat from Homestar Runner, type thecheat <word> instead.  This requires that both cowsay and lolcat are installed, and you'll need to copy the included thecheat.cow file into your cowsay cows folder (or make a link to it in your cows folder).  On my Mac, it looks like this:
ln -s ~/.cheatsheet/thecheat.cow /usr/local/Cellar/cowsay/3.04/share/cows/thecheat.cow

Editing the cheatsheet:

You can quickly edit the cheatsheet file using vicheat.  I chose that name to follow the same convention as visudo, but you can edit the alias in the .bashrc file if something else makes more sense to you.
I hope this is useful to some people out there, and I welcome your feedback!  Happy cheating!


## command_cheatsheet
#!/bin/bash
# BASH COMMAND CHEATSHEET

cat /etc/*release                                               # find Linux distribution version
cat /etc/*-release | uniq -u | grep 'release'                   # show Linux release
sudo fuser -k 80/tcp                                            # kill all processes using port 80 (useful if nginx won't stop/restart gracefully)
alias cdwww="cd /var/www/html/"                                 # add to ~/.bashrc for shortcut to webroot

# ansible
ansible-playbook <playbook>.yml --private-key ~/.ssh/<key>.pem	# specify a private key to use to connect when running playbooks on EC2 instances

# apt
apt list --installed                                            # list all installed packages
apt-cache policy |grep http |awk '{print $2 $3}' |sort -u       # list apt sources
apt-get install <package name>=<version>                        # install a specific version of a package

# AWS motd banner
sudo vim /etc/update-motd.d/30-banner                           # edit motd banner on AWS Amazon Linux AMI systems
sudo /usr/sbin/update-motd                                      # update motd banner from contents of /etc/update-motd.d/ on AWS Amazon Linux AMI systems

# cron
  sudo crontab -l -u <user>                                     # view cron jobs for a specific user
  sudo crontab -e -u <user>                                     # edit cron jobs for a specific user
  sudo sh -c 'tail -n +1 /var/spool/cron/*'                     # list crontab for all users
# cron time string format:
  * * * * *                                                     # cron time string character positions
  └─│─│─│─│── minute                                            # run cron job (0-59) minutes past the hour, or * for every minute
    └─│─│─│── hour                                              # run cron job (0-23) hours past midnight, or * for every hour
      └─│─│── day of month                                      # run cron job on day (1-31) of the month, or * for every day
        └─│── month                                             # run cron job during month (1-12) of the year, or * for every month
          └── day of week                                       # run cron job every (0-6) days past Sunday, or * for every day of the week
# cron time special characters:
  * (asterisk)                                                  # cron time: any/every
  , (comma)                                                     # cron time: value list separator
  - (hyphen)                                                    # cron time: defines range of values
  / (forward slash)                                             # cron time: step value
# cron time examples:
  * * * * *                                                     # run cron job every minute
  0 0-6,18-23 * * *                                             # run cron job hourly from 18:00 through 06:00
  10 */2 * * *                                                  # run cron job 10 minutes past the hour, every other hour
# See http://crontab.guru for more interactive cron examples

# docker
docker --version						# check Docker version
docker images							# list Docker images
docker search							# search the Docker Hub for images
docker pull <image>						# pull an image or a repository from Docker Hub or another registry
docker create <image>						# create a writeable container from an image and prepare it to run
docker run <image>						# creates container from an image and runs it (similar to docker create + docker start)
docker run -it centos:latest /bin/bash				# run a CentOS container, start bash and attach to to terminal
docker run -d centos:latest /bin/bash				# run a CentOS container in detached mode
docker start <container>					# start a stopped container
docker inspect <image or container>				# show low-level information on Docker objects
docker exec <container> <command>				# pass command to running container
docker exec -it <container> /bin/bash				# start a bash prompt in a running container and attach it to terminal
docker stop <container name>					# stop a running container
docker ps							# list running containers
docker ps -a							# list all containers, running or stopped
docker rm <container>						# remove container
docker rm `docker ps -a -q`					# remove all containers
docker rmi <image>						# remove image
docker rmi -f <image>						# remove image (force)

# git
git init								    # initialize empty git repo in .git/
git status								    # show current branch, list changes to be committed, untracked files, etc.
git add <file>								    # add untracked file to staging area
git add '*.txt'								    # add all new .txt files to staging area
git --git-dir=/my/path/.git/ --work-tree=/my/path/ add <file>		    # add file in another directory to staging area
git commit -m "<message>"						    # store staged changes
git --git-dir=/my/path/.git/ --work-tree=/my/path/ commit -m "<comment>"    # commit changes in another directory
git log									    # list changes committed so far
git remote add origin <https://some.repo.com>				    # add remote repository
git push -u origin master						    # push local changes to remote repo origin (-u stores params so only 'git push' is needed next time)
git pull origin master							    # check for changes on remote origin repo and pull them down
git diff HEAD								    # check what is different from most recent commit
git diff --staged							    # show changes within files that have already been staged
git reset <file>							    # unstage <file>
git branch								    # show branches and highlight which branch is currently being used
git branch <branch>							    # create branch called <branch>
git branch -d <branch>							    # delete <branch> branch
git checkout -- <file>							    # get rid of changes since last commit for <file>
git checkout <branch>							    # switch to branch <branch>
git checkout -b <branch>						    # create and switch to branch <branch>
git rm '*.txt'								    # deletes .txt files from disk and stages removal of the files in the repo
git merge <branch>							    # merge changes from <branch> branch into current branch
git clone <repo> .							    # clone repository in current local directory

# grep
grep -rli --exclude-dir={dir1,dir2,dir3} keyword /search/path   # search path for pattern with exceptions
grep "^[^#;]" file.name                                         # show only non-commented lines (ignore comments)
grep '^[[:blank:]]*[^[:blank:]#;]' file.name                    # show only non-commented non-blank lines (ignore comments and blank lines)

# history (bash)
HISTCONTROL=ignorespace                                         # tell bash not to record commands starting with space to history (add to .bashrc to make persistent)
history -d <number>                                             # delete command <number> from bash history

# kubernetes
kubectl exec -it <pod name> -n <namespace> -- /bin/bash		# accesh shell in a container running in a kubernetes/EKS pod (see https://kubernetes.io/docs/tasks/debug-application-cluster/get-shell-running-container/)

# ln
ln -s <target> <name>						# creates a symbolic link (symlink) to <target> called <name>

# magento
php bin/magento admin:user:create --admin-user='<user>' --admin-password='<password>' --admin-email='<user@email.com>' --admin-firstname='<first>' --admin-lastname='<last>'    # create admin user
rm -rf var/di/* var/generation/* var/cache/* var/log/* var/page_cache/* var/session/* var/view_preprocessed/* pub/static/*  # clear out magento cache and temp directories
magento setup:install                                           # install Magento software
magento setup:upgrade                                           # update the Magento software
magento setup:di:compile                                        # run single-tenant compiler
magento setup:static-content:deploy                             # deploy static content
magento cache:clean                                             # clean cache type(s)
magento cache:flush                                             # flush cache storage used by cache type(s)
magento module:{enable|disable}                                 # enable or disable modules
magento setup:db:status                                         # check if the database is up-to-date with the code
export PATH=$PATH:/var/www/html/bin                             # add to ~/.bashrc to add magento commands to $PATH

# mysql
mysql -u db_username -p db_name < db_file.sql                   # import database 'db_name' from 'db_file.sql' into mysql (use gunzip if file.sql.gz)
SELECT User FROM mysql.user;                                    # mysql > show all database users
SHOW DATABASES;                                                 # mysql > show all databases
sed -e 's/DEFINER[ ]*=[ ]*[^*]*\*/\*/' file.sql > newfile.sql   # make a mysql dump ready to import without SUPER permissions error
# dump mysql database 'db_name' on server 'db_server' to file:
mysqldump -h <db_server> -u <db_username> -p <db_name> --single-transaction | sed -e 's/DEFINER[ ]*=[ ]*[^*]*\*/\*/' | gzip > <db_file>.sql.gz

# netstat
sudo netstat -tulpn | grep :80                                  # find out what is running/listening on port 80
sudo netstat | grep http | wc -l                                # check how many http connections are open

# nginx
sudo nginx -s reload                                            # reload nginx config
sudo nginx -s quit                                              # gracefully shutdown nginx
sudo nginx -s stop                                              # terminates nginx process
sudo nginx -t                                                   # nginx config syntax check (pre-load)
sudo nginx -T                                                   # displays currently running configs
sudo nginx -v                                                   # checks nginx version
ps aux | grep "[n]ginx"                                         # check running nginx processes
service nginx status                                            # check nginx service status

# rsync
rsync -havz --stats --progress -e "ssh -i /path/to/sshkey.pem" /path/to/local/file user@remotehost:~/   # transfer local file to home directory on remote server
rsync -havz --stats --progress -e "ssh -i /path/to/sshkey.pem" user@remotehost:~/file ~/                # transfer file from home directory on remote server to local home directory

# screen
screen                                                          # start screen
<ctrl-a> c                                                      # creat new screen window
<ctrl-a> n                                                      # go to next screen window
<ctrl-a> p                                                      # go to previous screen window
<ctrl-a> "						"	# show list of screen windows (allows you to select a window to change to)
<ctrl-a> w                                                      # show screen window bar
<ctrl-a> m                                                      # monitor current screen window for activity, alert when active
<ctrl-a> _                                                      # monitor current screen window for silence or no activity, alert when inactive
<ctrl-a> d                                                      # detach from current screen
screen -ls                                                      # list screen sessions
screen -r [pid.session.name]                                    # re-attach to screen session
https://www.howtoforge.com/linux_screen                         # decent screen tutorial

# ssh
ssh-keygen -t rsa										# generate ssh keys
find ~/.ssh -type f -exec chmod -R 600 {} \; && find ~/.ssh -type d -exec chmod -R 700 {} \;	# fix permissions on ssh folder and keys
ssh-keygen -R hostname										# remove a host from known_hosts file

# tar
tar xvzf file.tar.gz                                            # extract entire .tar.gz archive
tar tvf file.tar.gz                                             # view a table of contents by listing all files in achieve
tar xvjf file.tar.bz2                                           # extract file which was compressed using a bZip2 compressor
tar zcvf archive-name.tar.gz directory-name                     # compress entire directory

# tmux
tmux new -s session_name					# creates a new tmux session named session_name
tmux attach -t session_name					# attaches to an existing tmux session named session_name
tmux switch -t session_name					# switches to an existing session named session_name
tmux list-sessions						# lists existing tmux sessions
tmux kill-session -t :0-9					# kill tmux session
tmux detach							# detach the currently attached session
tmux new-window							# create a new window
tmux select-window -t :0-9					# move to the window based on index
tmux rename-window						# rename the current window
tmux split-window						# splits the window into two vertical panes
tmux split-window -h						# splits the window into two horizontal panes
tmux swap-pane -[UDLR]						# swaps pane with another in the specified direction
tmux select-pane -t :.+						# selects the next pane in numerical order
tmux list-keys							# lists out every bound key and the tmux command it runs
tmux list-commands						# lists out every tmux command and its arguments
tmux info							# lists out every session, window, pane, its pid, etc.
tmux source-file ~/.tmux.conf					# reloads the current tmux configuration (based on a default tmux config)
  # tmux shortcuts:
  <ctrl-b> d							# tmux detach
  <ctrl-b> c							# tmux new-window
  <ctrl-b> 0-9							# tmux select-window
  <ctrl-b> ,							# tmux rename-window
  <ctrl-b> "						"	# tmux split-window
  <ctrl-b> %							# tmux split-window -h
  <ctrl-b> { or }						# tmux swap-pane -[UDLR]
  # tmux crash course:
  https://robots.thoughtbot.com/a-tmux-crash-course

# user and group management
useradd -s /sbin/nologin dbuser                                 # add a user without a valid login shell (to establish SSH tunnels for DB access, for example)
groups <user>                                                   # list groups <user> is in
sudo usermod -a -G <group> <user>                               # add user to group

# varnish
varnishlog -g request -q 'ReqMethod eq "PURGE"'                 # view logged varnish purge requsts

# yum
yum list all                                                    # list all installed and available packages
yum list installed                                              # list all installed packages
yum list available                                              # list all available packages
yum repolist all                                                # list all yum repositories and their status
yum repolist enabled                                            # list only enabled yum repositories
yum repolist disabled                                           # list disabled yum repositories
yum --disablerepo=* --enablerepo=repo_name install [packages]   # only install packages from the 'repo_name' repository

# zip, gzip
gunzip file.gz                                                  # extract .gz file without tar
gzcat <filename>                                                # look at gzipped file contents without extracting it


## screenshot_cheat.png

      
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              screenshot_cheat.png
            
          
## screenshot_thecheat.png

      
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              screenshot_thecheat.png
            
          
## thecheat.cow

      
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              thecheat.cow
            
          
            View raw
              (Sorry about that, but we can’t show files that are this big right now.)

	####################
	# CLI cheatsheet #
	####################

	# cheatsheet directory location:
	CHEATDIR=~/.cheatsheet

	# Use 'vicheat' to edit the cheatsheet
	alias vicheat='vim $CHEATDIR/command_cheatsheet'

	# Use 'cheat <word>' to search for <word> in the cheatsheet
	cheat() {
	grep -iw --color=auto $1 $CHEATDIR/command_cheatsheet
	}

	# OPTIONAL: Use 'thecheat <word>' to have cheatsheet results delivered in color by Homestar Runner's The Cheat.
	# (Requires cowsay, lolcat, and thecheat.cow)
	thecheat () {
	grep -iw $1 $CHEATDIR/command_cheatsheet \| cowsay -f thecheat -n \| lolcat
	}
	#!/bin/bash
	# BASH COMMAND CHEATSHEET

	cat /etc/*release # find Linux distribution version
	cat /etc/*-release \| uniq -u \| grep 'release' # show Linux release
	sudo fuser -k 80/tcp # kill all processes using port 80 (useful if nginx won't stop/restart gracefully)
	alias cdwww="cd /var/www/html/" # add to ~/.bashrc for shortcut to webroot

	# ansible
	ansible-playbook <playbook>.yml --private-key ~/.ssh/<key>.pem # specify a private key to use to connect when running playbooks on EC2 instances

	# apt
	apt list --installed # list all installed packages
	apt-cache policy \|grep http \|awk '{print $2 $3}' \|sort -u # list apt sources
	apt-get install <package name>=<version> # install a specific version of a package

	# AWS motd banner
	sudo vim /etc/update-motd.d/30-banner # edit motd banner on AWS Amazon Linux AMI systems
	sudo /usr/sbin/update-motd # update motd banner from contents of /etc/update-motd.d/ on AWS Amazon Linux AMI systems

	# cron
	sudo crontab -l -u <user> # view cron jobs for a specific user
	sudo crontab -e -u <user> # edit cron jobs for a specific user
	sudo sh -c 'tail -n +1 /var/spool/cron/*' # list crontab for all users
	# cron time string format:
	* * * * * # cron time string character positions
	└─│─│─│─│── minute # run cron job (0-59) minutes past the hour, or * for every minute
	└─│─│─│── hour # run cron job (0-23) hours past midnight, or * for every hour
	└─│─│── day of month # run cron job on day (1-31) of the month, or * for every day
	└─│── month # run cron job during month (1-12) of the year, or * for every month
	└── day of week # run cron job every (0-6) days past Sunday, or * for every day of the week
	# cron time special characters:
	* (asterisk) # cron time: any/every
	, (comma) # cron time: value list separator
	- (hyphen) # cron time: defines range of values
	/ (forward slash) # cron time: step value
	# cron time examples:
	* * * * * # run cron job every minute
	0 0-6,18-23 * * * # run cron job hourly from 18:00 through 06:00
	10 /2 * * # run cron job 10 minutes past the hour, every other hour
	# See http://crontab.guru for more interactive cron examples

	# docker
	docker --version # check Docker version
	docker images # list Docker images
	docker search # search the Docker Hub for images
	docker pull <image> # pull an image or a repository from Docker Hub or another registry
	docker create <image> # create a writeable container from an image and prepare it to run
	docker run <image> # creates container from an image and runs it (similar to docker create + docker start)
	docker run -it centos:latest /bin/bash # run a CentOS container, start bash and attach to to terminal
	docker run -d centos:latest /bin/bash # run a CentOS container in detached mode
	docker start <container> # start a stopped container
	docker inspect <image or container> # show low-level information on Docker objects
	docker exec <container> <command> # pass command to running container
	docker exec -it <container> /bin/bash # start a bash prompt in a running container and attach it to terminal
	docker stop <container name> # stop a running container
	docker ps # list running containers
	docker ps -a # list all containers, running or stopped
	docker rm <container> # remove container
	docker rm `docker ps -a -q` # remove all containers
	docker rmi <image> # remove image
	docker rmi -f <image> # remove image (force)

	# git
	git init # initialize empty git repo in .git/
	git status # show current branch, list changes to be committed, untracked files, etc.
	git add <file> # add untracked file to staging area
	git add '*.txt' # add all new .txt files to staging area
	git --git-dir=/my/path/.git/ --work-tree=/my/path/ add <file> # add file in another directory to staging area
	git commit -m "<message>" # store staged changes
	git --git-dir=/my/path/.git/ --work-tree=/my/path/ commit -m "<comment>" # commit changes in another directory
	git log # list changes committed so far
	git remote add origin <https://some.repo.com> # add remote repository
	git push -u origin master # push local changes to remote repo origin (-u stores params so only 'git push' is needed next time)
	git pull origin master # check for changes on remote origin repo and pull them down
	git diff HEAD # check what is different from most recent commit
	git diff --staged # show changes within files that have already been staged
	git reset <file> # unstage <file>
	git branch # show branches and highlight which branch is currently being used
	git branch <branch> # create branch called <branch>
	git branch -d <branch> # delete <branch> branch
	git checkout -- <file> # get rid of changes since last commit for <file>
	git checkout <branch> # switch to branch <branch>
	git checkout -b <branch> # create and switch to branch <branch>
	git rm '*.txt' # deletes .txt files from disk and stages removal of the files in the repo
	git merge <branch> # merge changes from <branch> branch into current branch
	git clone <repo> . # clone repository in current local directory

	# grep
	grep -rli --exclude-dir={dir1,dir2,dir3} keyword /search/path # search path for pattern with exceptions
	grep "^[^#;]" file.name # show only non-commented lines (ignore comments)
	grep '^[[:blank:]]*[^[:blank:]#;]' file.name # show only non-commented non-blank lines (ignore comments and blank lines)

	# history (bash)
	HISTCONTROL=ignorespace # tell bash not to record commands starting with space to history (add to .bashrc to make persistent)
	history -d <number> # delete command <number> from bash history

	# kubernetes
	kubectl exec -it <pod name> -n <namespace> -- /bin/bash # accesh shell in a container running in a kubernetes/EKS pod (see https://kubernetes.io/docs/tasks/debug-application-cluster/get-shell-running-container/)

	# ln
	ln -s <target> <name> # creates a symbolic link (symlink) to <target> called <name>

	# magento
	php bin/magento admin:user:create --admin-user='<user>' --admin-password='<password>' --admin-email='<user@email.com>' --admin-firstname='<first>' --admin-lastname='<last>' # create admin user
	rm -rf var/di/* var/generation/* var/cache/* var/log/* var/page_cache/* var/session/* var/view_preprocessed/* pub/static/* # clear out magento cache and temp directories
	magento setup:install # install Magento software
	magento setup:upgrade # update the Magento software
	magento setup:di:compile # run single-tenant compiler
	magento setup:static-content:deploy # deploy static content
	magento cache:clean # clean cache type(s)
	magento cache:flush # flush cache storage used by cache type(s)
	magento module:{enable\|disable} # enable or disable modules
	magento setup:db:status # check if the database is up-to-date with the code
	export PATH=$PATH:/var/www/html/bin # add to ~/.bashrc to add magento commands to $PATH

	# mysql
	mysql -u db_username -p db_name < db_file.sql # import database 'db_name' from 'db_file.sql' into mysql (use gunzip if file.sql.gz)
	SELECT User FROM mysql.user; # mysql > show all database users
	SHOW DATABASES; # mysql > show all databases
	sed -e 's/DEFINER[ ]=[ ][^]\/\/' file.sql > newfile.sql # make a mysql dump ready to import without SUPER permissions error
	# dump mysql database 'db_name' on server 'db_server' to file:
	mysqldump -h <db_server> -u <db_username> -p <db_name> --single-transaction \| sed -e 's/DEFINER[ ]=[ ][^]\/\/' \| gzip > <db_file>.sql.gz

	# netstat
	sudo netstat -tulpn \| grep :80 # find out what is running/listening on port 80
	sudo netstat \| grep http \| wc -l # check how many http connections are open

	# nginx
	sudo nginx -s reload # reload nginx config
	sudo nginx -s quit # gracefully shutdown nginx
	sudo nginx -s stop # terminates nginx process
	sudo nginx -t # nginx config syntax check (pre-load)
	sudo nginx -T # displays currently running configs
	sudo nginx -v # checks nginx version
	ps aux \| grep "[n]ginx" # check running nginx processes
	service nginx status # check nginx service status

	# rsync
	rsync -havz --stats --progress -e "ssh -i /path/to/sshkey.pem" /path/to/local/file user@remotehost:~/ # transfer local file to home directory on remote server
	rsync -havz --stats --progress -e "ssh -i /path/to/sshkey.pem" user@remotehost:~/file ~/ # transfer file from home directory on remote server to local home directory

	# screen
	screen # start screen
	<ctrl-a> c # creat new screen window
	<ctrl-a> n # go to next screen window
	<ctrl-a> p # go to previous screen window
	<ctrl-a> " " # show list of screen windows (allows you to select a window to change to)
	<ctrl-a> w # show screen window bar
	<ctrl-a> m # monitor current screen window for activity, alert when active
	<ctrl-a> _ # monitor current screen window for silence or no activity, alert when inactive
	<ctrl-a> d # detach from current screen
	screen -ls # list screen sessions
	screen -r [pid.session.name] # re-attach to screen session
	https://www.howtoforge.com/linux_screen # decent screen tutorial

	# ssh
	ssh-keygen -t rsa # generate ssh keys
	find ~/.ssh -type f -exec chmod -R 600 {} \; && find ~/.ssh -type d -exec chmod -R 700 {} \; # fix permissions on ssh folder and keys
	ssh-keygen -R hostname # remove a host from known_hosts file

	# tar
	tar xvzf file.tar.gz # extract entire .tar.gz archive
	tar tvf file.tar.gz # view a table of contents by listing all files in achieve
	tar xvjf file.tar.bz2 # extract file which was compressed using a bZip2 compressor
	tar zcvf archive-name.tar.gz directory-name # compress entire directory

	# tmux
	tmux new -s session_name # creates a new tmux session named session_name
	tmux attach -t session_name # attaches to an existing tmux session named session_name
	tmux switch -t session_name # switches to an existing session named session_name
	tmux list-sessions # lists existing tmux sessions
	tmux kill-session -t :0-9 # kill tmux session
	tmux detach # detach the currently attached session
	tmux new-window # create a new window
	tmux select-window -t :0-9 # move to the window based on index
	tmux rename-window # rename the current window
	tmux split-window # splits the window into two vertical panes
	tmux split-window -h # splits the window into two horizontal panes
	tmux swap-pane -[UDLR] # swaps pane with another in the specified direction
	tmux select-pane -t :.+ # selects the next pane in numerical order
	tmux list-keys # lists out every bound key and the tmux command it runs
	tmux list-commands # lists out every tmux command and its arguments
	tmux info # lists out every session, window, pane, its pid, etc.
	tmux source-file ~/.tmux.conf # reloads the current tmux configuration (based on a default tmux config)
	# tmux shortcuts:
	<ctrl-b> d # tmux detach
	<ctrl-b> c # tmux new-window
	<ctrl-b> 0-9 # tmux select-window
	<ctrl-b> , # tmux rename-window
	<ctrl-b> " " # tmux split-window
	<ctrl-b> % # tmux split-window -h
	<ctrl-b> { or } # tmux swap-pane -[UDLR]
	# tmux crash course:
	https://robots.thoughtbot.com/a-tmux-crash-course

	# user and group management
	useradd -s /sbin/nologin dbuser # add a user without a valid login shell (to establish SSH tunnels for DB access, for example)
	groups <user> # list groups <user> is in
	sudo usermod -a -G <group> <user> # add user to group

	# varnish
	varnishlog -g request -q 'ReqMethod eq "PURGE"' # view logged varnish purge requsts

	# yum
	yum list all # list all installed and available packages
	yum list installed # list all installed packages
	yum list available # list all available packages
	yum repolist all # list all yum repositories and their status
	yum repolist enabled # list only enabled yum repositories
	yum repolist disabled # list disabled yum repositories
	yum --disablerepo=* --enablerepo=repo_name install [packages] # only install packages from the 'repo_name' repository

	# zip, gzip
	gunzip file.gz # extract .gz file without tar
	gzcat <filename> # look at gzipped file contents without extracting it