llluksa · February 26, 2024 03:42
diff --git a/basics.sh b/basics.sh
 # Kernel version of a Linux system
 uname -a

 # Check if lib is installed
 ldconfig -p | grep libgtk

 # Services
 service <service name> status (old school)
 systemctl status <service name>

 # disk free
 df -ah
 # dir total size
 du -sh /dir
 # size of directories with a dept
 du -h --max-dept=1

 # CPU use
 ps aux | grep nginx
 top # more info
 htop # not by default but better graphics

 # Mount drive e.g. usb stick
 mount /dev/sda2 /mnt
 # check for existing mounts
 mount
 # automatically mount volume at boot:
 less /etc/fstab

 # Manual pages for commands
 man ps

 # Change host name
 sudo vi /etc/hostname
 sudo reboot

 # Create alias
 alias <aliasname>='<cmd>'

 # Curl
 # add header
 curl -H "Host:jupyterhub.luksa" 192.168.0.153:30010 -v
diff --git a/certs.sh b/certs.sh
 # get pk:
 openssl pkcs12 -in abc.pfx -nocerts -out key.pem && openssl rsa -in key.pem -out key.pem

 # get fullchain:
 # openssl pkcs12 -in prod.pfx -nokeys -out cert.pem
 openssl pkcs12 -in abc.pfx -nokeys | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > cert.pem
diff --git a/certs_azure.sh b/certs_azure.sh
 # (default azure pw is empty), extract key only:
 openssl pkcs12 -in abc.pfx -nocerts -out key.pem

 # (create a passphrase), extract certs only:
 openssl pkcs12 -in abc.pfx -nokeys -out cert.pem

 # remove passphrase from key and clean up the file:
 openssl rsa -in key.pem -out key.pem
diff --git a/cron.txt b/cron.txt
 cj.sh # add e.g. echo 'I run a cronjob!' >> /home/malu/cb-sh-log.txt
 crontab -l # add cron job e.g.: * * * * * /home/malu/cj.sh
 sudo service cron status
 sudo service cron start

 https://devhints.io/cron
 https://serverfault.com/questions/449651/why-is-my-crontab-not-working-and-how-can-i-troubleshoot-it
diff --git a/eof.sh b/eof.sh
 # use sudo sh -c an EOF if permissions are an issue:
 # https://stackoverflow.com/questions/82256/how-do-i-use-sudo-to-redirect-output-to-a-location-i-dont-have-permission-to-wr
 sudo sh -c 'cat << EOF > /etc/telegraf/telegraf_new.conf
 something
 EOF
 '
diff --git a/secrets.sh b/secrets.sh
 # Export secret env var without having it in history:
 read -s -p "Enter password:" MROOTPASS 
 export MROOTPASS

 # or disable history for anything that starts with whitespace
 export HISTCONTROL=ignorespace
 # now start a command with whitespace... it won't be in history :)
  export PW=abc
diff --git a/sed.sh b/sed.sh
 # Replace all literal \n with a new line:
 sed 's/\\n/\n/g' # cat myfile | sed 's/\\n/\n/g' > myfile
 # Delete all lines which start with #:
 sed '/^#/d'

 # add "#" to the beggening of each line
 sed 's/^/#/' file.txt
 sed s/^/'terraform state mv '/ refactor.sh > refactor2.sh

 # add "#" to the end of each line
 sed s/$/:80/ file.txt > another_file.txt
 sed s/$/' \&\& \\'/ refactor2.sh > refactor3.sh
diff --git a/ssh.sh b/ssh.sh
 # set keys permissions
 chmod 600 ~/.ssh/id_rsa

 # SCP
 # download a file from server
 scp -i id_rsa_ansible_monit ansible@10.0.130.11:/etc/telegraf/telegraf.conf .
 # downlaod a directory:
 scp -i id_rsa_ansible_monit -r ansible@10.0.130.11:/etc/dir ./dir
 # SSH pub key copy
 # cat and pipe the result to the server
 cat id_rsa.pub | ssh ubuntu@192.168.0.153 'cat >> /home/ubuntu/.ssh/authorized_keys'
diff --git a/vim.sh b/vim.sh
 # start edit
 vim file.tf
 # quit
 :q
 # write
 :w
 # write and quite
 :wq
 # quit without changes
 :q! 
 # jump to a line
 :set number (see line numbers)
 # start writing
 :i
 # delete a line
 dd
 # delete 10 lines
 10dd
 # undo
 :u
 # redo
 ctrl r
 # looking for string 'provisioner'
 /provisioner
 # replace all 'privisioner' strings with 'foo' plus confirm with enters
 :%s/provisioner/foo/g
	# Kernel version of a Linux system
	uname -a

	# Check if lib is installed
	ldconfig -p \| grep libgtk

	# Services
	service <service name> status (old school)
	systemctl status <service name>

	# disk free
	df -ah
	# dir total size
	du -sh /dir
	# size of directories with a dept
	du -h --max-dept=1

	# CPU use
	ps aux \| grep nginx
	top # more info
	htop # not by default but better graphics

	# Mount drive e.g. usb stick
	mount /dev/sda2 /mnt
	# check for existing mounts
	mount
	# automatically mount volume at boot:
	less /etc/fstab

	# Manual pages for commands
	man ps

	# Change host name
	sudo vi /etc/hostname
	sudo reboot

	# Create alias
	alias <aliasname>='<cmd>'

	# Curl
	# add header
	curl -H "Host:jupyterhub.luksa" 192.168.0.153:30010 -v
	# get pk:
	openssl pkcs12 -in abc.pfx -nocerts -out key.pem && openssl rsa -in key.pem -out key.pem

	# get fullchain:
	# openssl pkcs12 -in prod.pfx -nokeys -out cert.pem
	openssl pkcs12 -in abc.pfx -nokeys \| sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > cert.pem
	# (default azure pw is empty), extract key only:
	openssl pkcs12 -in abc.pfx -nocerts -out key.pem

	# (create a passphrase), extract certs only:
	openssl pkcs12 -in abc.pfx -nokeys -out cert.pem

	# remove passphrase from key and clean up the file:
	openssl rsa -in key.pem -out key.pem
	cj.sh # add e.g. echo 'I run a cronjob!' >> /home/malu/cb-sh-log.txt
	crontab -l # add cron job e.g.: * * * * * /home/malu/cj.sh
	sudo service cron status
	sudo service cron start

	https://devhints.io/cron
	https://serverfault.com/questions/449651/why-is-my-crontab-not-working-and-how-can-i-troubleshoot-it
	# use sudo sh -c an EOF if permissions are an issue:
	# https://stackoverflow.com/questions/82256/how-do-i-use-sudo-to-redirect-output-to-a-location-i-dont-have-permission-to-wr
	sudo sh -c 'cat << EOF > /etc/telegraf/telegraf_new.conf
	something
	EOF
	'
	# Export secret env var without having it in history:
	read -s -p "Enter password:" MROOTPASS
	export MROOTPASS

	# or disable history for anything that starts with whitespace
	export HISTCONTROL=ignorespace
	# now start a command with whitespace... it won't be in history :)
	export PW=abc
	# Replace all literal \n with a new line:
	sed 's/\\n/\n/g' # cat myfile \| sed 's/\\n/\n/g' > myfile
	# Delete all lines which start with #:
	sed '/^#/d'

	# add "#" to the beggening of each line
	sed 's/^/#/' file.txt
	sed s/^/'terraform state mv '/ refactor.sh > refactor2.sh

	# add "#" to the end of each line
	sed s/$/:80/ file.txt > another_file.txt
	sed s/$/' \&\& \\'/ refactor2.sh > refactor3.sh
	# set keys permissions
	chmod 600 ~/.ssh/id_rsa

	# SCP
	# download a file from server
	scp -i id_rsa_ansible_monit ansible@10.0.130.11:/etc/telegraf/telegraf.conf .
	# downlaod a directory:
	scp -i id_rsa_ansible_monit -r ansible@10.0.130.11:/etc/dir ./dir
	# SSH pub key copy
	# cat and pipe the result to the server
	cat id_rsa.pub \| ssh ubuntu@192.168.0.153 'cat >> /home/ubuntu/.ssh/authorized_keys'
	# start edit
	vim file.tf
	# quit
	:q
	# write
	:w
	# write and quite
	:wq
	# quit without changes
	:q!
	# jump to a line
	:set number (see line numbers)
	# start writing
	:i
	# delete a line
	dd
	# delete 10 lines
	10dd
	# undo
	:u
	# redo
	ctrl r
	# looking for string 'provisioner'
	/provisioner
	# replace all 'privisioner' strings with 'foo' plus confirm with enters
	:%s/provisioner/foo/g