Cheat Sheet

apt
Install specific package version
apt-cache policy kubelet
apt-get install kubelet=1.13.4-00
Hold version
apt-mark hold kubelet kubeadm kubectl
Remove hold version
apt-mark unhold kubelet kubeadm kubectl
crontab
List crontab for all users
for user in $(cut -f1 -d: /etc/passwd); do crontab -u $user -l; done
du
Hidden files
du -sch .[!.]* * |sort -h
Sort by size
du -hsc * |sort -h
ncurses interface
sudo apt install ncdu
ncdu
find
find and du -hsc
find . \
  -name "*.txt" \
  -maxdepth 2 \
  -type d \
  -exec du -csh --block-size=1M {} \;
find and rm
find . -name "server.log-2018*" \
  -print0 | xargs -0 rm -f
Find and sed
find . -type f -print0 | xargs -0 sed -i 's/OLD/NEW/g'
Tools
fzf
GitHub - junegunn/fzf: A command-line fuzzy finder
GitHub
​
grep
Sort by second column:
grep -air "count-" file-name* |sort -k2
Hard drive management
List all hard drives and partitions:
sudo lsblk -o NAME,FSTYPE,SIZE,MOUNTPOINT,LABEL
journalctl
Get all logs
Get 20 most recent:
journalctl -n 20
Get process logs
journalctl -u kubelet
Processes management
Check if process is running
#!/bin/bash
service=mongod
​
if (( $(ps -ef | grep -v grep | grep $service | wc -l) > 0 ))
then
  echo "$service is running!!!"
else
  /etc/init.d/$service start
fi
Swap management
Create swap partition
sudo /bin/dd if=/dev/zero of=/var/swap.0 bs=1M count=1024
sudo /sbin/mkswap /var/swap.0
sudo /sbin/swapon /var/swap.0
echo "/var/swap.0 swap swap defaults 0 0" >> /etc/fstab
Replace 1024 with your desired swap size in MB.
Disable swap
sudo swapoff -a
systemctl
Check if process is enable
systemctl is-enabled PROCESS-NAME-HERE
List all services
systemctl list-units --type service --all
telnet
Client close connection
Input ctrl+]
Then execute: 
close
wget
Backup entire website.
wget \
     --recursive \
     --no-clobber \
     --page-requisites \
     --html-extension \
     --convert-links \
     --restrict-file-names=windows \
     --domains devops.buzz \
     --no-parent \
         https://www.devops.buzz/public/
References
​https://www.linuxjournal.com/content/downloading-entire-web-site-wget​

AWS - Previous

Cognito with Amplify and React

Next - Bash / Shell

Tools

Last modified 1yr ago

Copy link

Outline

apt

Install specific package version

Hold version

Remove hold version

crontab

List crontab for all users

Hidden files

Sort by size

ncurses interface

find

find and du -hsc

find and rm

Find and sed

Tools

grep

Hard drive management

journalctl

Get all logs

Get process logs

Processes management

Check if process is running

Swap management

Create swap partition

Disable swap

systemctl

Check if process is enable

List all services

telnet

Client close connection

wget

Backup entire website.