linux.md

Linux cheat sheet

• cheat sheet cmd

  curl cheat.sh/ls

• Security cheat sheet

place for scripts, permanent script

### system wide for all users
# System-wide .bashrc file for interactive bash(1) shells.
/etc/bash.bashrc
# system-wide .profile file for the Bourne shell (sh(1)
/etc/profile
/etc/environment
/etc/profile.d/my_new_update.sh

### during user login
~/.bash_profile
# executed by Bourne-compatible login shells.
~/.profile 

# during open the terminal, executed by bash for non-login shells.
~/.bashrc

socket proxy, proxy to remote machine

ssh -D <localport> <user>@<remote host>

and checking if it is working for 'ssh -D 7772 [email protected]'

ssh -o "ProxyCommand nc -x 127.0.0.1:7772 %h %p" [email protected]

tunnel, port forwarding from local machine to outside

ssh -L <local_port>:<remote_host from ssh_host>:<remote_port> <username>@<ssh_host>
ssh -L <local_port>:<remote_host from ssh_host>:<remote_port> <ssh_host>

ssh -L 28010:vldn337:8010 localhost
ssh -L 28010:remote_host:8010 user_name@remote_host

# destination service on the same machine as ssh_host
# localport!=remote_port (28010!=8010)
ssh -L 28010:127.0.0.1:8010 user_name@remote_host

from local port 7000 to remote 5005

ssh -L 7000:127.0.0.1:5005 [email protected]

browser(ext_host) -> 134.190.2.5 -> 134.190.200.201

[email protected]:~$ ssh -L 134.190.2.5:8091:134.190.200.201:8091 [email protected]
user@ext_host:~$ wget 134.190.2.5:8091/echo 

tunnel, port forwarding from outside to localmachine

# ssh -R <remoteport>:<local host name>:<local port> <hostname>
# localy service on port 9092 should be started
# and remotelly you can reach it out just using 127.0.0.1:7777
ssh -R 7777:127.0.0.1:9092 localhost

tunnel for remote machine with proxy, local proxy for remote machine, remote proxy access

//TODO local=======>remote
after that, remote can use local as proxy

first of all start local proxy (proxychains or redsock)

sudo apt install privoxy
sudo vim /etc/privoxy/config
# listen-address  127.0.0.1:9999
# forward-socks5t / http://my-login:[email protected]:8080 .
# forward-socks4a / http://my-login:[email protected]:8080 .
# or 
# forward   /      http://my-login:[email protected]:8080
systemctl start privoxy

# locally proxy server on port 9999 should be started
ssh -D 9999 127.0.0.1 -t ssh -R 7777:127.0.0.1:9999 [email protected]

# from remote machine you can execute 
wget -e use_proxy=yes -e http_proxy=127.0.0.1:7777 https://google.com

ssh suppress banner, ssh no invitation

ssh -q my_server.org

ssh verbosive, ssh log, debug ssh

ssh -vv my_server.org

local proxy cntlm, cntlm proxy

  app_1 --.
           \
  app_2 --- ---> local proxy <---> External Proxy <---> WWW
   ...     /
  app_n --'

install cntlm

# temporarily set proxy variables for curl and brew to work in this session
$ export http_proxy=http://<user>:<password>@proxy-url:proxy-port
$ export https_proxy=$http_proxy

# update & upgrade apt
$ sudo --preserve-env=http_proxy,https_proxy apt-get update
$ sudo --preserve-env=http_proxy,https_proxy apt-get upgrade

# finally, install cntlm
sudo --preserve-env=http_proxy,https_proxy apt-get install cntlm

edit configuration

vim ~/.config/cntlm/cntlm.conf

Username user-name
Domain  domain-name
Proxy   proxy-url:proxy-port
NoProxy localhost, 127.0.0.*, 10.*, 192.168.*, *.zur
Listen  3128

or globally

sudo vim /etc/cntlm.conf

~/bin/proxy-start.sh

#!/bin/sh

pidfile=~/.config/cntlm/cntlm.pid

if [ -f $pidfile ]; then
kill "$(cat $pidfile)"
sleep 2
fi

cntlm -c ~/.config/cntlm/cntlm.conf -P $pidfile -I

source ~/bin/proxy-settings.sh

proxy_url="http://127.0.0.1:3128"
export http_proxy=$proxy_url
export https_proxy=$http_proxy
export HTTP_PROXY=$http_proxy
export HTTPS_PROXY=$http_proxy

export _JAVA_OPTIONS="-Dhttp.proxyHost=127.0.0.1 -Dhttp.proxyPort=3128 -Dhttps.proxyHost=127.0.0.1 -Dhttps.proxyPort=3128 -Dhttps.nonProxyHosts=localhost|*.ubsgroup.net|*.muc -Dhttp.nonProxyHosts=localhost|*.ubsgroup.net|*.zur"

check status

sudo invoke-rc.d cntlm status
ss -lt | grep 3128

possible solution to detect remote client to your machine

# open access
ping -s 120 -c 1 146.255.193.66
ping -s 121 -c 1 146.255.193.66
ping -s 122 -c 1 146.255.193.66

# close access
ping -s 123 -c 1 146.255.193.66

open ports, open connections, listening ports, application by port, application port, process port, pid port

# list of open files
sudo lsof -i -P -n | grep LISTEN
# list of open connections
sudo netstat -tulpan | grep LISTEN
# print pid of process that occupying 9999 port
sudo ss -tulpan 'sport = :9999'

# open input output
iotop

mount drive to path mount

# <drive> <path>
sudo mount /dev/sdd /tin

mount remote filesystem via ssh, map folder via ssh, ssh remote folder

sudo mkdir /mnt/vendor-cluster-prod
sudo sshfs -o allow_other,IdentityFile=~/.ssh/id_rsa [email protected]:/remote/path/folder /mnt/vendor-cluster-prod
# sudo fusermount -u /remote/path/folder
# sudo umount /remote/path/folder

mount remote filesystem via ftp

sudo apt install curlftpfs
sudo mkdir /mnt/samsung-note
curlftpfs testuser:[email protected]:2221 /mnt/samsung-note/

mount windows folder, mount windows shared folder

sudo apt install nfs-common
sudo apt install cifs-utils

sudo mkdir -p /mnt/windows-computer
USER_NAME='my-username'
USER_DOMAIN='ZUR'
USER_SERVER='//u015029.ubsbank.net/home$/x453337/'
sudo mount -t cifs -o auto,gid=$(id -g),uid=$(id -u),username=$USER_NAME,domain=$USER_DOMAIN,vers=2.1 $USER_SERVER /mnt/windows-computer

mount issue

bad option;  for several filesystems (e.g. nfs, cifs) you might need a /sbin/mount.<type> helper program.

sudo apt-get install nfs-common
sudo apt-get install cifs-utils

mount usb drive temporary mount disk

sudo mount /dev/sdd    /media/tina-team
umount /dev/sdd

mount usb drive permanently mount, map drive

sudo mkdir /mnt/disks/k8s-local-storage1
sudo chmod 755 /mnt/disks/k8s-local-storage1
sudo ln -s /mnt/disks/k8s-local-storage1/nfs nfs1
ls -la /mnt/disks
ls -la /mnt

sudo blkid
sudo vim /etc/fstab
# add record
# UUID=42665716-1f89-44d4-881c-37b207aecb71 /mnt/disks/k8s-local-storage1 ext4 defaults 0 0

# refresg fstab reload
sudo mount -av
ls /mnt/disks/k8s-local-storage1

option 2

sudo vim /etc/fstab
# add line
# /dev/disk/by-uuid/8765-4321    /media/usb-drive         vfat   0   0

# copy everything from ```mount```
# /dev/sdd5 on /media/user1/e91bd98f-7a13-43ef-9dce-60d3a2f15558 type ext4 (rw,nosuid,nodev,relatime,uhelper=udisks2)
# /dev/sda1 on /media/kali/usbdata type fuseblk (rw,nosuid,nodev,relatime,user_id=0,group_id=0,default_permissions,allow_other,blksize=4096,uhelper=udisks2)

# systemctl daemon-reload

sudo mount -av

mount remote drive via network

10.55.0.3:/mnt/disks/k8s-local-storage/nfs /mnt/nfs nfs rw,noauto,x-systemd.automount,x-systemd.device-timeout=10,timeo=14 0 0

drive uuid hdd uuid

blkid

list drives, drive list, attached drives

lsblk
fdisk -l

create filesystem, format drive

sudo mkfs -t xfs /dev/xvdb

sudo mke2fs /dev/xvdb

gpg signature check, asc signature check, crt signature check

kgpg --keyserver keyserver.ubuntu.com --recv-keys 9032CAE4CBFA933A5A2145D5FF97C53F183C045D
gpg --import john-brooks.asc

gpg --verify ricochet-1.1.4-src.tar.bz2.asc

gpg --keyserver keyserver.ubuntu.com --recv-keys D09FB15F1A24768DDF1FA29CCFEEF31651B5FDE8

connect to remote machine via ssh without credentials

# generate new RSA keys, create RSA
ssh-keygen -t rsa

( check created file /home/{user}/.ssh/id_rsa )

# if you have copied it, check permissions
chmod 700 ~/.ssh
chmod 700 ~/.ssh/*

copy ssh key to remote machine,

ssh-copy-id {username}@{machine ip}:{port}
ssh-copy-id -i ~/.ssh/id_rsa.pub -o StrictHostKeyChecking=no [email protected]
# manual execution
cat ~/.ssh/id_rsa.pub | ssh [email protected] 'cat >> ~/.ssh/authorized_keys'

# output nothing when ssh key exists, ssh check
ssh-copy-id [email protected] 2>/dev/null

login without typing password

sshpass -p my_password ssh [email protected]

automate copying password

./ssh-copy.expect my_user ubsad00015.vantage.org "my_passw" 

#!/usr/bin/expect -f
set user [lindex $argv 0];
set host [lindex $argv 1];
set password [lindex $argv 2];

spawn ssh-copy-id $user@$host
expect "])?"
send "yes\n"
expect "password: "
send "$password\n"
expect eof

sometimes need to add next

ssh-agent bash
ssh-add ~/.ssh/id_dsa or id_rsa

remove credentials ( undo previous command )

ssh-keygen -f "/home/{user}/.ssh/known_hosts" -R "10.140.240.105"

copy ssh key to remote machine, but manually:

cat .ssh/id_rsa.pub | ssh {username}@{ip}:{port} "cat >> ~/.ssh/authorized_keys"
chmod 700 ~/.ssh ;
chmod 600 ~/.ssh/authorized_keys

issue broken pipe ssh

vim ~/.ssh/config

Host *
    ServerAliveInterval 30
    ServerAliveCountMax 5

ssh fingerprint checking

ssh -o StrictHostKeyChecking=no [email protected]
sshpass -p my_password ssh -o StrictHostKeyChecking=no [email protected]

# check ssh-copy-id, check fingerprint
ssh-keygen -F bmw000013.adv.org
# return 0 ( and info line ), return 1 when not aware about the host

manage multiply keys

$ ls ~/.ssh
-rw-------  id_rsa
-rw-------  id_rsa_bmw
-rw-r--r--  id_rsa_bmw.pub
-rw-r--r--  id_rsa.pub

$ cat ~/.ssh/config 
IdentityFile ~/.ssh/id_rsa_bmw
IdentityFile ~/.ssh/id_rsa

copy from local machine to remote one, remote copy

scp filename.txt [email protected]:~/temp/filename-from-local.txt

copy from remote machine to local

scp -r [email protected]:~/temp/filename-from-local.txt filename.txt 

copy directory to remote machine, copy folder to remote machine

scp -pr /source/directory user@host:the/target/directory

the same as local copy folder

cp -var /path/to/folder /another/path/to/folder

copy file with saving all attributes, copy attributes, copy file with attributes

cp -r --preserve=mode,ownership,timestamps /path/to/src /path/to/dest
cp -r --preserve=all /path/to/src /path/to/dest

change owner

# change owner recursively for current folder and subfolders
sudo chown -R $USER .

syncronize folders, copy everything between folders, diff folder

# print diff 
diff -qr /tmp/first-folder/ /tmp/second-folder

# local sync
rsync -r /tmp/first-folder/ /tmp/second-folder
## Attributes Verbosive Unew-modification-time
rsync -avu /tmp/first-folder/ /tmp/second-folder

# sync remote folder to local ( copy FROM remote )
rsync -avz [email protected]:~/test-2020-02-28  /home/projects/temp/test-2020-02-28
# sync remote folder to local ( copy FROM remote ) with specific port 
rsync -avz -e 'ssh -p 2233' [email protected]:~/test-2020-02-28  /home/projects/temp/test-2020-02-28

# sync local folder to remote ( copy TO remote )
rsync -avz /home/projects/temp/test-2020-02-28  [email protected]:~/test-2020-02-28  
# sync local folder to remote ( copy TO remote ) include exclude
rsync -avz --include "*.txt" exclude "*.bin" /home/projects/temp/test-2020-02-28  [email protected]:~/test-2020-02-28  

function cluster-prod-generation-sync-to(){
  if [[ $1 == "" ]]; then
      return 1
  fi
  rsync -avz . $USER_GT_LOGIN@ubsdpd00013.vantage.org:~/$1
}

create directory on remote machine, create folder remotely, ssh execute command, ssh remote execution

ssh user@host "mkdir -p /target/path/"

ssh execute command and detach ssh execute detached ssh command SIGHUP Signal Hang UP

each_node="bpde00013.ubsbank.org"
REMOTE_SCRIPT="/opt/app/1.sh"
REMOTE_OUTPUT_LOG="/var/log/1.output"

ssh $REMOTE_USER"@"$each_node "nohup $REMOTE_SCRIPT </dev/null > $REMOTE_OUTPUT_LOG 2>&1 &"

ssh xserver, ssh graphical

export DISPLAY=:0.0
xterm

here document, sftp batch command with bash

sftp -P 2222 my_user@localhost << END_FILE_MARKER
ls
exit
END_FILE_MARKER

map folder to another path, mount dir to another location

# map local /tmp folder to another path/drive
sudo mount -B /tmp /mapped_drive/path/to/tmp

mount cdrom ( for virtual machine )

sudo mount /dev/cdrom /mnt

create ram disc

mkdir -p /mnt/my-ram
mount -t tmpfs tmpfs /mnt/my-ram -o size=1024M

repeat command with predefined interval, execute command repeatedly

watch -n 60 'ls -la | grep archive'

execute command in case of changes watch file

ls *.txt | entr firefox 

repeat last command

!!

repeat last command with substring "flow" included into whole command line

!?flow

execute in current dir, inline shell execution

. goto-command.sh

directories into stack

pushd
popd
dirs

to previous folder

cd -

sudo reboot

shutdown -r now

sort, order

# simple sort
sort <filename>

#  sort by column ( space delimiter )
sort -k 3 <filename>

# sort by column number, with delimiter, with digital value ( 01, 02....10,11 )
sort -g -k 11 -t "/" session.list

# sort with reverse order
sort -r <filename>

print file with line numbers, output linenumbers

cat -n <filename>

split and merge big files

split --bytes=1M /path/to/image/image.jpg /path/to/image/prefixForNewImagePieces

cat prefixFiles* > newimage.jpg

cut big file, split big file, cat after threshold

cat --lines=17000 big_text_file.txt

unique lines (duplications) into file

add counter and print result

uniq -c

duplicates

print only duplicates ( distinct )

uniq -d

print all duplications

uniq -D

unique

uniq -u

print column from file, split string with separator

cut --delimiter "," --fields 2,3,4 test1.csv
cut --delimiter "," -f2,3,4 test1.csv

substring with fixed number of chars: from 1.to(15) and 1.to(15) && 20.to(50)

cut -c1-15
cut -c1-15,20-50

output to file without echo on screen, echo without typing on screen

echo "text file" | grep "" > $random_script_filename

system log information, logging

# read log
tail -f /var/log/syslog
# write to system log
echo "test" | /usr/bin/logger -t cronjob
# write log message to another system
logger --server 192.168.1.10 --tcp "This is just a simple log line"

/var/log/messages

repository list of all repositories

sudo cat /etc/apt/sources.list*

add repository

add-apt-repository ppa:inkscape.dev/stable

you can find additional file into

/etc/apt/sources.list.d

search after adding

apt-cache search inkscape

update from one repo, single update

sudo apt-get update -o Dir::Etc::sourcelist="sources.list.d/cc-ros-mirror.list" -o Dir::Etc::sourceparts="-" -o APT::Get::List-Cleanup="0" 

remove repository

sudo rm /etc/apt/sources.list.d/inkscape.dev*

avoid to put command into history, hide password into history, avoid history

add space before command

bash settings, history lookup with arrows, tab autocomplete

~/.inputrc

"\e[A": history-search-backward
"\e[B": history-search-forward
set show-all-if-ambiguous on
set completion-ignore-case on
TAB: menu-complete
"\e[Z": menu-complete-backward
set show-all-if-unmodified on
set show-all-if-ambiguous on

script settings

# stop execution when non-zero exit
set -e

# stop execution when error happend even inside pipeline 
set -eo pipeline

# stop when access to unknown variable 
set -u

# print each command before execution
set -x

# export source export variables
set -a
source file-with-variables.env

execute command via default editor

ctrl+x+e

edit last command via editor

fc

folder into bash script

working folder

pwd

process directory process working dir

pwdx <process id>

bash reading content of the file to command-line parameter

--extra-vars 'rpm_version=$(cat version.txt)'
--extra-vars 'rpm_version=`cat version.txt`'

all command line arguments to another program

original.sh $*

auto execute during startup, autoexec

folder: /etc/rc1.d ( rc2.d ... )
contains links to ../init.d/<name of bash script>
should understand next options: start, stop, restart

#! /bin/sh
# /etc/init.d/blah
#

# Some things that run always
touch /var/lock/blah

# Carry out specific functions when asked to by the system
case "$1" in
  start)
    echo "Starting script blah "
    ;;
  stop)
    echo "Stopping script blah"
    ;;
  *)
    echo "Usage: /etc/init.d/blah {start|stop}"
    exit 1
    ;;
esac

exit 0

or custom service, service destination

sudo vim /etc/systemd/system/YOUR_SERVICE_NAME.service

Description=GIVE_YOUR_SERVICE_A_DESCRIPTION

Wants=network.target
After=syslog.target network-online.target

[Service]
Type=simplesystemctl
ExecStart=YOUR_COMMAND_HERE
Restart=on-failure
RestartSec=10
KillMode=process

[Install]
WantedBy=multi-user.target

service with docker container, service dockerized app

[Unit]
Description=Python app 
After=docker.service
Requires=docker.service

[Service]
TimeoutStartSec=5
Restart=always
ExecStartPre=-/usr/bin/docker stop app
ExecStartPre=-/usr/bin/docker rm app
ExecStart=/usr/bin/docker run \
    --env-file /home/user/.env.app \
    --name app \
    --publish 5001:5001 \
    appauth
ExecStop=/usr/bin/docker stop app

[Install]
WantedBy=multi-user.target

managing services

# alternative of chkconfig
# alternative of sysv-rc-conf

# list all services
systemctl --all
systemctl enable YOUR_SERVICE_NAME
systemctl start YOUR_SERVICE_NAME
systemctl status YOUR_SERVICE_NAME
systemctl daemon-reload YOUR_SERVICE_NAME
systemctl stop YOUR_SERVICE_NAME

reset X-server, re-start xserver, reset linux gui ubuntu only

Ctrl-Alt-F1

sudo init 3
sudo init 5

sudo pkill X

sudo service lightdm stop
sudo service lightdm force-reload

start

sudo startx

sudo service lightdm start

xserver automation

keymap

apt-get install xdotool
xdotool windowactivate $each_window 
xdotool key --window $each_window Return alt+f e Down Down Return

find all symlinks

ls -lR . | grep ^l

grep asterix, grep between

cat secrets | grep ".*Name.*Avvo.*"

grep exclude, grep without folder

grep -ir --exclude-dir=node_modules "getServerSideProps"

full path to file, file behind symlink, absolute path to file

readlink -f {file}
readlink -f `dirname $0`
realpath {file}

or

python -c 'import os.path; print(os.path.realpath("symlinkName"))'

filename from path

basename {file}

folder name from path, folder of file, file directory, file folder, parent folder, parent dir

dirname {file}
nautilus "$(dirname -- "$PATH_TO_SVG_CONFLUENCE")"

print full path to files inside folder

ls -d <path to folder>/*

ls directory, ls current folder, ls path, ls by path

find $FOLDER -maxdepth 4 -mindepth 4 | xargs ls -lad

real path to link

readlink 'path to symlink'

where is program placed, location of executable file

which "program-name"

permission denied

# issue with permission ( usually on NFS or cluster )
# find: '/mnt/nfs/ml-training-mongodb-pvc/journal': Permission denied
# 
# solution:
sudo docker run --volume  /mnt/nfs:/nfs -it busybox /bin/sh
chmod -R +r /nfs/ml-training-mongodb-pvc/journal

find file by name

locate {file name}

exclude DB

/etc/updatedb.conf

find files by mask

locate -ir "brand-reader*"
locate -b "brand-reader"

you need to update filedatabase: /var/lib/mlocate/mlocate.db

sudo updatedb

find file, search file, skip permission denied

find . -name "prd-ticket-1508.txt"  2>&1 | grep -v "Permission denied"

find multiply patterns

find . -name "*.j2" -o -name "*.yaml"

find file by last update time

find / -mmin 2

find with exec find md5sum

find . -exec md5sum {} \;
find . -name "*.json" | while read each_file; do cat "$each_file" > "${each_file}".txt; done

delete files that older than 5 days

find ./my_dir -mtime +5 -type f -delete
# default variable, env var default
find ${IMAGE_UPLOAD_TEMP_STORAGE:-/tmp/image_upload} -mtime +1 -type f -delete

find files/folders by name and older than 240 min

find /tmp -maxdepth 1 -name "native-platform*" -mmin +240 | xargs -I {} sudo rm -r {} \; >/dev/null 2>&1

find files/folders by regexp and older than 240 min, find depth, find deep

find /tmp -maxdepth 1 -mmin +240 -iname "[0-9]*\-[0-9]" | xargs -I {} sudo rm -r {} \; >/dev/null 2>&1

find large files, find big files

find . -type f -size +50000k -exec ls -lh {} \;
find . -type f -size +50000k -exec ls -lh {} \; | awk '{ print $9 ": " $5 }'

find files on special level, find on level

find . -maxdepth 5 -mindepth 5

find by mask find

find /mapr/vantage/data/store/processed/*/*/*/*/*/Metadata/file_info.json

find with excluding folders, find exclude

find . -type d -name "dist" ! -path  "*/node_modules/*"

find function declaration, print function, show function

type <function name>
declare -f <function name>

builtin, overwrite command, rewrite command

cd()
{
   # builtin going to execute not current, but genuine function
   builtin cd /home/projects
}

folder size, dir size, directory size, size directory, size folder size of folder, size of directory

sudo du -shc ./*
sudo du -shc ./* | sort -rh | head -5

free space, space size, dir size

df -ha
df -hT /

# size of folder
du -sh /home

# size my sub-folders
du -mh /home

# print first 5 leaders of size-consumers
# slow way: du -a /home | sort -n -r | head -n 5
sudo du -shc ./* | sort -rh | head -5

du -ch /home
# find only files with biggest size ( top 5 )
find -type f -exec du -Sh {} + | sort -rh | head -n 5

yum ( app search )

yum list {pattern}

( example: yum list python33 )

yum install {package name}
yum repolist all
yum info {package name}
yumdb info {package name}

rpm (http://ftp.rpm.org/max-rpm/ch-rpm-query.html)

print all packages and sort according last updated on top

rpm -qa --last

information about package ( help page, how to execute ... )

rpm -qai

information about package with configuration

rpm -qaic
rpm -qi wd-tomcat8-app-brandserver

jobs

fg, bg, jobs

stop process and start it into background

ctrl-Z
bg

stop process and resume it, disconnect from process and leave it running

ctrl-Z
fg

resume process by number into list 'jobs'

fg 2

shell replacing, redirect output to file, fork new process start

bash
exec > output-file.txt
date
# the same as 'exit'
exec <&-
cat output-file.txt

output to file with variable, output to variable

gen_version="5.2.1"
$(find /mapr/dp.prod/vantage/data/processed/gen/$gen_version/ -maxdepth 5 -mindepth 5 | awk -F '/' '{print $14}' > gt-$gen_version.list)

execute command and exit

bash
exec ls -la

execute command from string, execute string, run string

echo "ls" | xargs -i sh -c "{}"

disconnect from terminal and let command be runned

ctrl-Z
disown -a && exit

postponed execution, execute command by timer, execute command from now, timer command

for graphical applications DISPLAY must be specified

• using built-in editor

at now + 5 minutes
at> DISPLAY=:0 rifle /path/to/image
^D

• using inline execution

echo "DISPLAY=:0 rifle /path/to/image/task.png" | at now + 1 min
echo "DISPLAY=:0 rifle /path/to/image/task.png" | at 11:01

print all files that process is reading

strace -e open,access <command to run application>

find process by name

ps fC firefox
pgrep firefox

pid of process by name

pidof <app name>
pidof chrome

process list, process tree

ps axjf
ps -ef --forest
ps -fauxw

process full command, ps full, ps truncate

ps -ewwo pid,cmd

windows analogue of 'ps aux'

wmic path win32_process get Caption, Processid, Commandline

kill -3

output to log stop process

remove except one file

rm -rf  -- !(exclude-filename.sh)

cron

You have to escape the % signs with % where is file located

sudo less /var/spool/cron/crontabs/$USER

cron activating

sudo service cron status

all symbols '%' must be converted to '%'

# edit file
crontab -e
# list of all jobs
crontab -l

adding file with cron job

echo " * * * * echo `date` >> /out.txt" >> print-date.cron
chmod +x print-date.cron
crontab print-date.cron

logs

sudo tail -f /var/log/syslog

is cron running

ps -ef | grep cron | grep -v grep

start/stop/restart cron

systemctl start cron
systemctl stop cron
systemctl restart cron

skip first line, pipe skip line

# skip first line in output
docker ps -a | awk '{print $1}' | tail -n +2

error to null

./hbase.sh 2>/dev/null

stderr to stdout, error to out

sudo python3 echo.py > out.txt 2>&1 &
sudo python3 echo.py &> out.txt &
sudo python3 echo.py > out.txt &

grep with line number

grep -nr "text for search" .

grep only in certain folder without recursion, grep current folder, grep in current dir

# need to set * or mask for files in folder !!!
grep -s "search_string" /path/to/folder/*
sed -n 's/^search_string//p' /path/to/folder/*

# grep in current folder
grep -s "search-string" * .*

grep before

grep -B 4
grep --before 4

grep after

grep -A 4
grep --after 4

grep between, print between lines

oc describe pod/gateway-486-bawfps | awk '/Environment:/,/Mounts:/'

grep text into files

grep -rn '.' -e '@Table'
grep -ilR "@Table" .

grep OR operation

cat file.txt | grep -e "occurence1" -e "occurence2"
cat file.txt | grep -e "occurence1\|occurence2"

grep AND operation

cat file.txt | grep -e "occurence1" | grep -e "occurence2"

grep not included, grep NOT

cat file.txt | grep -v "not-include-string"
cat file.txt | grep -v -e "not-include-string" -e "not-include-another"

grep with file mask

grep -ir "memory" --include="*.scala"

grep with regexp, grep regexp

grep -ir --include=README.md ".*base" 2>/dev/null

echo "BN_FASDLT/1/20200624T083332_20200624T083350_715488_BM60404_BN_FASDLT.MF4" | awk -F "/" '{print $NF}' | grep "[0-9]\{8\}"

grep with filename

grep  -rH -A 2 "@angular/core"

grep without permission denied

grep -ir --include=README.md "base" 2>/dev/null

grep filename, grep name

grep -lir 'password'

inner join for two files, compare string from different files

grep -F -x -f path-to-file1 path-to-file2
grep --fixed-strings --line-regexp -f path-to-file1 path-to-file2

difference between two files without spaces

diff -w file1.txt file2.txt

show difference in lines with context

diff -c file1.txt file2.txt

show difference between two dates, date difference, time difference

apt install dateutils
dateutils.ddiff -i '%Y%m%d%H%M%S' -f '%y %m %d %H %M %S' 20160312000101 20170817040001

adjust time, adjust clock, sync clock, computer clock

/etc/systemd/timesyncd.conf.d/90-time-sync.conf

[Time]
NTP=ntp.ubuntu.com
FallbackNTP=ntp.ubuntu.com

restart time sync service

timedatectl set-ntp true && systemctl restart systemd-timesyncd.service

replace character into string

array = echo $result | tr {}, ' ' 

change case of chars ( upper, lower )

echo "hello World" | tr '[:lower:]' '[:upper:]

replace all chars

echo "hello World 1234 woww" | tr -dc 'a-zA-Z'

replace text in all files of current directory, replace inline, replace inplace, inline replace

sed --in-place 's/LinkedIn/Yahoo/g' *
# replace tab symbol with comma symbol
sed --in-place 's/\t/,/g' one_file.txt

no editor replacement, no vi no vim no nano, add line without editor, edit property without editor

# going to add new line in property file without editor
sed --in-place 's/\[General\]/\[General\]\nenable_trusted_host_check=0/g' matomo-php.ini

date formatting, datetime formatting, timestamp file, file with timestamp

date +%H:%M:%S:%s
date +%Y-%m-%d-%H:%M:%S:%s
# output file with currenttime
python3 /imap-message-reader.py > message_reader`date +%H:%M:%S`.txt

generate random string

urandom | tr -dc 'a-zA-Z0-9' | fold -w 8 | tr '[:upper:]' '[:lower:]' | head -n 1

find inside zip file(s), grep zip, zip grep

zgrep "message_gateway_integration" /var/lib/brand-server/cache/zip/*.zip

grep zip, find inside zip, inside specific file line of text

ls -1 *.zip | xargs -I{} unzip -p {} brand.xml  | grep instant-limit | grep "\\."

unzip into specific folder

unzip file.zip -d output_folder

unzip without asking for action

unzip -o file.zip -d output_folder

unzip tar file from url, wget unzip, wget untar

wget -qO- https://nodejs.org/dist/v10.16.3/node-v10.16.3-linux-x64.tar.xz | tar xvz - -C /target/directory

untar

tar zxvf backup.tgz

pipeline chain 'to file'

echo "hello from someone" | tee --append out.txt
echo "hello from someone" | tee --append out.txt > /dev/null

vi

vi wrap( :set wrap, :set nowrap )

shortcut	description
/	search forward
?	search backward
n	next occurence
N	prev occurence

command prompt, change console prompt

export PROMPT_COMMAND="echo -n \[\$(date +%H:%M:%S)\]\ "

.bashrc of ubuntu

if [ "$color_prompt" = yes ]; then
#    PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
    PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@$(date +%d%m_%H%M)\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '

else
#    PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '
    PS1='${debian_chroot:+($debian_chroot)}\u:\$(date +%d.%m_%H:%M)\w\$ '

fi
unset color_prompt force_color_prompt

command line color prompt color console

# green
export PS1=`printf "\033[31m$ staging \033[39m"`
# red
export PS1=`printf "\033[32m$ staging \033[39m"`

Color	Foreground	Background
Black	\033[30m	\033[40m
Red	\033[31m	\033[41m
Green	\033[32m	\033[42m
Orange	\033[33m	\033[43m
Blue	\033[34m	\033[44m
Magenta	\033[35m	\033[45m
Cyan	\033[36m	\033[46m
Light gray	\033[37m	\033[47m
Fallback to distro's default	\033[39m	\033[49m

last executed exit code

echo $?

memory dump

cat /proc/meminfo

max open files

cat /proc/sys/fs/file-max

open file by type, open image

mimetype -d {filename}
xdg-open {filename}
w3m {filename}

open in browser, open url

sensible-browser http://localhost:3000/api/status
x-www-browser http://localhost:3000/api/status
# for MacOS
open http://localhost:3000/api/status

wget post

wget --method=POST http://{host}:9000/published/resources/10050001.zip

wget to console

wget -O- http://{host}:8500/wd-only/getBrandXml.jsp?brand=229099017 > /dev/null  2>&1

wget to console without additional info

wget -nv -O- http://{host}:8500/wd-only/getBrandXml.jsp?brand=229099017 2>/dev/null

wget to specific file, download file to specific file

wget -O out.zip http://{host}:9000/published/resources/10050001.zip
# in case of complex output path
curl -s http://{host}:9000/published/resources/10050001.zip --create-dirs -o /home/path/to/folder/file.zip

wget to specific folder

wget http://host:9090/wd-only/1005000.zip --directory-prefix="/home/temp/out"

wget https without checking certificate

wget --no-check-certificate https://musan999999.mueq.adas.intel.com:8888/data-api/session/

wget with specific timeout

wget --tries=1 --timeout=5 --no-check-certificate https://musan999999.mueq.adas.intel.com:8888/data-api/session/

wget proxy, wget via proxy

wget -e use_proxy=yes -e http_proxy=127.0.0.1:7777 https://mail.ubsgroup.net/

or just with settings file "~/.wgetrc"

use_proxy = on
http_proxy =  http://username:[email protected]:port/
https_proxy =  http://username:[email protected]:port/
ftp_proxy =  http://username:[email protected]:port/

zip files, zip all files

zip -r bcm-1003.zip *

zip file without saving path, zip path cleanup

zip --junk_paths bcm-1003.zip *

using parameters for aliases

alias sublime_editor=/Applications/SublimeEditor/Sublime

subl(){
  sublime_editor "$1" &
}

print alias, print function

alias sublime_editor
type subl

sed cheat sheet, replace

replace "name" with "nomen" string
sed 's/name/nomen/g'

# replace only second occurence
# echo "there is a test is not a sentence" | sed 's/is/are/2'

example of replacing all occurences in multiply files

for each_file in `find -name "*.java"`; do
	sed --in-place 's/vodkafone/cherkavi/g' $each_file
done

print line by number from output, line from pipeline

locate -ir "/zip$" | sed -n '2p'

issue with windows/unix carriage return

/usr/bin/bash^M: bad interpreter: No such file or directory

solution

sed -i -e 's/\r$//' Archi-Ubuntu.sh 

calculate amount of strings

ps -aux | awk 'BEGIN{a=0}{a=a+1}END{print a}'

boolean value

true
false

last changed files, last updated file

find -cmin -2

cURL

curl username, curl with user and password, curl credentials

curl -u username:password http://example.com

curl head

curl --head http://example.com

curl redirect, redirect curl, curl 302

curl -L http://example.com

curl PUT example with file

curl -X PUT --header "Content-Type: application/vnd.wirecard.brand.apis-v1+json;charset=ISO-8859-1" -H "x-username: cherkavi" [email protected] http://q-brands-app01.wirecard.sys:9000/draft/brands/229099017/model/country-configurations

curl POST example

curl -X POST http://localhost:8983/solr/collection1/update?commit=true -H "Content-Type: application/json" --data '{"add":"data"}'
curl -X POST http://localhost:8983/solr/collection1/update?commit=true -H "Content-Type: application/json" --data-raw '{"add":"data"}'

curl -X POST http://localhost:8983/solr/collection1/update?commit=true -H "Content-Type: application/json" --data-binary '{"add":"data"}'
# or with bash variable
SOME_DATA="my_personal_value"
curl -X POST http://localhost:8983/solr/collection1/update?commit=true -H "Content-Type: application/json" --data-binary '{"add":"'$SOME_DATA'"}'
# or with data from file
curl -X POST http://localhost:8983/test -H "Content-Type: application/json" --data-binary '@/path/to/file.json'
# or with multipart body
curl -i -X POST -H "Content-Type: multipart/form-data" -F "[email protected]" -F "userid=1234" http://mysuperserver/media/upload/
# POST request GET style
curl -X POST "http://localhost:8888/api/v1/notification/subscribe?email=one%40mail.ru&country=2&state=517&city=qWkbs&articles=true&questions=true&listings=true" -H "accept: application/json"

curl escape, curl special symbols

# https://kb.objectrocket.com/elasticsearch/elasticsearch-cheatsheet-of-the-most-important-curl-requests-252
curl -X GET "https://elasticsearch-label-search-prod.vantage.org/autolabel/_search?size=100&q=moto:*&pretty"

escape single quotas

echo "'" 'sentence' "'"

curl without progress, curl silent

• curl -s -X GET http://google.com
• curl --silent -X GET http://google.com
• curl http://google.com 2>/dev/null

curl certificate skipping, curl ssl, curl https, curl skip ssl

curl --insecure -s -X GET http://google.com

curl with additional output, curl verbosive mode

curl --verbose --insecure -s -X GET http://google.com

curl cookie, curl header cookie

chrome extension cookies.txt

# send predefined cookie to url
curl -b path-to-cookie-file.txt -X GET url.com

# send cookie from command line
curl --cookie "first_cookie=123;second_cookie=456;third_cookie=789" -X GET url.com

# send cookie from command line 
curl 'http://localhost:8000/members/json-api/auth/user' -H 'Cookie: PHPSESSID=5c5dddcd96b9f2f41c2d2f87e799feac'

# collect cookie from remote url and save in file
curl -c cookie-from-url-com.txt -X GET url.com

curl with encoding to another codepage, from win1251 to utf8

curl "http://some.resource/read_book.php?id=66258&p=1" | iconv --from-code WINDOWS-1251 --to-code UTF-8

curl with parsing, curl part of the page

curl status code, curl response code

airflow_trigger(){
  SESSION_ID=$1
  ENDPOINT=$2
  BODY='{"conf":{"session_id":"'$SESSION_ID'","branch":"merge_labels"}}'
  curl --silent -w "response-code: %{http_code}\n" --data-binary $BODY -u $AIRFLOW_USER:$AIRFLOW_PASSWORD -X POST $ENDPOINT
  return $?
}
DAG_NAME='labeling'
airflow_trigger $each_session "https://airflow.vantage.org/api/experimental/dags/$DAG_NAME/dag_runs"

curl --show-error "http://some.resource/read_book.php?id=66258&p=1"

curl execution time

curl --max-time 10 -so /dev/null -w '%{time_total}\n' google.com

curl script curl replacement

curl "https://{foo,bar}.com/file_[1-4].webp" --output "#1_#2.webp"

xml pretty print, xml format

xmllint --format /path/to/file.xml > /path/to/file-formatted.xml

xml validation

xmllint --noout file.xml; echo $?

json output pretty print, json pretty print

echo output.json | jq .

json parsing, parse json, parsing json, json processing

jq playground

echo '[{"id": 1, "name": "Arthur", "age": "21"},{"id": 2, "name": "Richard", "age": "32"}]' | \
jq ".[] | .name"

echo '[{"id": 1, "name": "Arthur", "age": "21"},{"id": 2, "name": "Richard", "age": "32"}]' | \
jq '.[] | if .name == "Richard" then . else empty end | [.id, .name] | @csv'

# convert from yaml to json, retrieve values from json, convert to csv
cat temp-pod.yaml | yq - r -j --prettyPrint | jq '[.metadata.namespace, .metadata.name, .spec.template.spec.nodeSelector."kubernetes.io/hostname"] | @csv'

echo '{"smart_collections":[{"id":270378401973},{"id":270378369205}]}' | jq '. "smart_collections" | .[] | .id'

parsing yaml, yaml processing

yq examples

# read value
cat k8s-pod.yaml | yq r - --printMode pv  "metadata.name"

# convert to JSON
cat k8s-pod.yaml | yq - r -j --prettyPrint

chmod recursively

chmod -R +x <folder name>

# remove world access 
chmod -R o-rwx /opt/sm-metrics/grafana-db/data
# remove group access
chmod -R g-rwx /opt/sm-metrics/grafana-db/data
# add rw access for current user
chmod u+rw screenshot_overlayed.png

find . -name "*.sql" -print0 | xargs -0 chmod 666

create dozen of folders using one-line command

mkdir -p some-folder/{1..10}/{one,two,three}

execute command with environment variable, new environment variable for command

ONE="this is a test"; echo $ONE

activate environment variables from file, env file, export env, export all env, all variable from file, all var export, env var file

FILE_WITH_VAR=.env.local
source $FILE_WITH_VAR
export $(cut -d= -f1 $FILE_WITH_VAR)

# if you have comments in file
source $FILE_WITH_VAR
export `cat $FILE_WITH_VAR | awk -F= '{if($1 !~ "#"){print $1}}'`

system log file

/var/log/syslog

Debian install package via proxy, apt install proxy, apt proxy, apt update proxy

sudo http_proxy='http://user:@proxy.muc:8080' apt install meld

proxy places, change proxy, update proxy, system proxy

remember about escaping bash spec chars ( $,.@.... )

• .bashrc
• /etc/environment
• /etc/systemd/system/docker.service.d/http-proxy.conf
• /etc/apt/auth.conf

Acquire::http::Proxy "http://username:password@proxyhost:port";
Acquire::https::Proxy "http://username:password@proxyhost:port";

• snap

sudo snap set system proxy.http="http://user:[email protected]:8080"
sudo snap set system proxy.https="http://user:[email protected]:8080"

snap installation issue

# leads to error: cannot connect to the server
snap install <app>

# Unmask the snapd.service:
sudo systemctl unmask snapd.service

# Enable it:
systemctl enable snapd.service

# Start it:
systemctl start snapd.service

install version of app, install specific version, accessible application version

sudo apt list -a [name of the package]
sudo apt list -a kubeadm

install package for another architecture, install x86 on x64

dpkg --add-architecture i386
dpkg --print-architecture
dpkg --print-foreign-architectures
sudo apt-get install libglib2.0-0:i386 libgtk2.0-0:i386

installed package check, check package

apt list <name of package>

package update package mark

apt mark hold kubeadm
# install: this package is marked for installation.
# deinstall (remove): this package is marked for removal.
# purge: this package, and all its configuration files, are marked for removal.
# hold: this package cannot be installed, upgraded, removed, or purged.
# unhold: 
# auto: auto installed
# manual: manually installed

Debian update package

sudo apt-get install --only-upgrade {packagename}

Debian list of packages

sudo apt list
sudo dpkg -l

First letter	desired package state ("selection state")
u	unknown
i	install
r	remove/deinstall
p	purge (remove including config files)
h	hold

Second letter	current package state
n	not-installed
i	installed
c	config-files (only the config files are installed)
U	unpacked
F	half-configured (configuration failed for some reason)
h	half-installed (installation failed for some reason)
W	triggers-awaited (package is waiting for a trigger from another package)
t	triggers-pending (package has been triggered)

Third letter	error state (you normally shouldn't see a third letter, but a space, instead)
R	reinst-required (package broken, reinstallation required)

Debian list the versions available in your repo

sudo apt-cache madison {package name}

Debian install new version of package with specific version

sudo apt-get install {package name}={version}

Debian system cleanup

sudo apt-get clean
sudo apt-get autoremove --purge

uninstall specific app

sudo apt-get --purge remote {app name}

remove service ( kubernetes )

• sudo invoke-rc.d localkube stop
• sudo invoke-rc.d localkube status ( sudo service localkube status )
• sudo update-rc.d -f localkube remove
• sudo grep -ir /etc -e "kube"
• rm -rf /etc/kubernetes
• rm -rf /etc/systemd/system/localkube.service
• vi /var/log/syslog

last executed code, last script return value

echo $?

remove VMWare player

sudo vmware-installer -u vmware-player

pdf watermark, merge pdf files into one

pdftk original.pdf stamp watermark.pdf output output.pdf

version of OS, linux version

• lsb_release -a
• cat /etc/system-release
• uname -a

cidr calculator

print all networks

ip -4 a
ip -6 a

print all network interfaces

interfaces

switch on and off network interface

sudo ifdown lo && sudo ifup lo

restart network, switch off all interfaces

sudo service network-manager restart

vpn connection, connect to network

# status of all connections
nmcli d
nmcli connection
nmcli connection up id {name from previous command}
nmcli connection down id {name of connection}

connect to wifi

wifi_code='188790542'
point="FRITZ!Box 7400 YO"
nmcli device wifi connect  "$point" password $wifi_code
# sudo cat /etc/NetworkManager/system-connections/*

raw vpn connection

sudo openconnect --no-proxy {ip-address} --user={user name}
sudo openconnect --no-cert-check --no-proxy {ip-address} --user={user name} ---servercert

debug network collaboration, ip packages

example with reading redis collaboration ( package sniffer )

sudo ngrep -W byline -d docker0 -t '' 'port 6379'

debug connection, print collaboration with remote service, sniffer

#                    1------------     2--------------------     3--------------
sudo tcpdump -nvX -v src port 6443 and src host 10.140.26.10 and dst port not 22
# and, or, not

keystore

## list of certificates
keytool -list -keystore ./src/main/resources/com/ubs/crm/data/api/rest/server/keystore_server

## generating ssl key stores
keytool -genkeypair -keystore -keystore ./src/main/resources/com/ubs/crm/data/api/rest/server/keystore_server -alias serverKey -dname "CN=localhost, OU=AD, O=UBS AG, L=Zurich, ST=Bavaria, C=DE" -keyalg RSA
# enter password...

## Importing ( updating, adding ) trusted SSL certificates
keytool -import -file ~/Downloads/certificate.crt -keystore ./src/main/resources/com/ubs/crm/data/api/rest/server/keystore_server -alias my-magic-number

DNS

# current dns
sudo cat /etc/resolv.conf
# resolving hostname
dig {hostname}
#
systemd-resolve --status

encrypt file, decrypt file, encode/decode

gpg --symmetric {filename}
gpg --decrypt {filename}

# encrypt
# openssl [encryption type] -in [original] -out [output file]
openssl des3 -in original.txt -out original.txt.encrypted
# decrypt
# openssl [encryption type] -d -in [encrypted file] -out [original file]
openssl des3 -d -in original.txt.encrypted -out original.txt

# list of encryptors (des3):
openssl enc -list

add user into special group, add user to group

• adduser {username} {destination group name}
• edit file /etc/group

add :{username} to the end of line with {groupname}:x:999

create/add user, create user with admin rights

sudo useradd test

sudo useradd --create-home test --groups sudo 
# set password for new user
sudo passwd test
# set default bash shell 
chsh --shell /bin/bash tecmint

sudo for user, user sudo, temporary provide sudo

sudo adduser vitalii sudo
# close all opened sessions
# after your work done
sudo deluser vitalii sudo

admin rights for script, sudo rights for script, execute as root

sudo -E bash -c 'python3'

remove user

sudo userdel -r test

create group, assign user to group, user check group, user group user roles hadoop

sudo groupadd new_group
usermod --append --groups new_group my_user
id my_user

create folder for group, assign group to folder

chgrp new_group /path/to/folder

execute sudo with current env variables, sudo env var, sudo with proxy

sudo -E <command>

execute script with current env variables send to script

. ./airflow-get-log.sh
source ./airflow-get-log.sh
cat dag-runs-failed.id | . ./airflow-get-log.sh

print all logged in users, active users, connected users

users

w

who --all

print all users registered into system

cat /etc/passwd | cut --delimiter=: --fields=1

issue with ssh, ssh connection issue

when you see message:

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

use this:

ssh-keygen -R <host>

or

rm ~/.ssh/known_hosts

proxy

• proxy local, proxy for user /etc/profile.d/proxy.sh

export HTTP_PROXY=http://webproxy.host:3128
export http_proxy=http://webproxy.host:3128
export HTTPS_PROXY=http://webproxy.host:3128
export https_proxy=http://webproxy.host:3128
export NO_PROXY="localhost,127.0.0.1,.host,.viola.local"
export no_proxy="localhost,127.0.0.1,.host,.viola.local"

• global proxy, proxy global, system proxy, proxy system /etc/apt/apt.conf

Acquire::http::proxy "http://proxy.company.com:80/";
Acquire::https::proxy "https://proxy.company.com:80/";
Acquire::ftp::proxy "ftp://proxy.company.com:80/";
Acquire::socks5::proxy "socks://127.0.0.1:1080/";

• global proxy, proxy global, system proxy, proxy system /etc/environment

http_proxy=http://webproxy.host:3128
no_proxy="localhost,127.0.0.1,.host.de,.viola.local"

• for application

create environment for http

sudo gedit /etc/systemd/system/{service name}.service.d/http-proxy.conf

[Service]
Environment="http_proxy=http://user:[email protected]:8080"

create environment for https

sudo gedit /etc/systemd/system/{service name}.service.d/https-proxy.conf
[Service]
Environment="https_proxy=http://user:[email protected]:8080"

restart service, service restart

$ sudo systemctl daemon-reload
$ sudo systemctl restart {service name}

enable automatic start, disable autostart

sudo systemctl enable {service name}
sudo systemctl disable {service name}

service check logs

systemctl status {service name}
journalctl -u {service name} -e
# print all units
journalctl -F _SYSTEMD_UNIT

# system log
journalctl -f -l 
# system log for app log
$ journalctl -f -l -u python -u mariadb
# system log since 300 second
$ journalctl -f -l -u httpd -u mariadb --since -300

check settings

systemctl show {service name} | grep proxy

• for snapd

# export SYSTEM_EDITOR="vim"
# export SYSTEMD_EDITOR="vim"
sudo systemctl edit snapd.service
# will edit: /etc/systemd/system/snapd.service.d/override.conf

add next lines

[Service]
Environment=http_proxy=http://proxy:port
Environment=https_proxy=http://proxy:port

restart service

sudo systemctl daemon-reload
sudo systemctl restart snapd.service

snap proxy settings

sudo snap set system proxy.http="http://user:[email protected]:8080"
sudo snap set system proxy.https="http://user:[email protected]:8080"
export proxy_http="http://user:[email protected]:8080"
export proxy_https="http://user:[email protected]:8080"
sudo snap search visual 

apache server

manage httpd

# apache server installation, apache server run, web server run, webserver start
sudo su
yum update -y
yum install -y httpd
service httpd start
chkconfig httpd
chkconfig httpd on
vim /var/www/html/index.html

debian

# installation
sudo su
apt update -y
apt install -y apache2

# service 
sudo systemctl status apache2.service
sudo systemctl start apache2.service

# change index html
vim /var/www/html/index.html

# Uncomplicated FireWall
ufw app list
ufw allow 'Apache'
ufw status

# enable module
a2enmod rewrite

# disable module
# http://manpages.ubuntu.com/manpages/trusty/man8/a2enmod.8.html
a2dismod rewrite

# enable or disable site/virtual host
# http://manpages.ubuntu.com/manpages/trusty/man8/a2ensite.8.html
a2dissite *.conf
a2ensite my_public_special.conf

activate ssl module

sudo a2enmod ssl
# sudo a2dismod ssl

# tutorial
vim /usr/share/doc/apache2/README.Debian.gz

# creating self-signed certificates
sudo make-ssl-cert generate-default-snakeoil --force-overwrite

# check certificates
sudo ls -la /etc/ssl/certs/ssl-cert-snakeoil.pem
sudo ls -la /etc/ssl/private/ssl-cert-snakeoil.key

cert configuration

vim /etc/apache2/sites-available/default-ssl.conf

                SSLCertificateFile      /etc/ssl/certs/ssl-cert-snakeoil.pem
                SSLCertificateKeyFile /etc/ssl/private/ssl-cert-snakeoil.key

restart apache

sudo service apache2 restart

---

Another tutorial https://www.digicert.com/easy-csr/openssl.htm https://www.digicert.com/kb/csr-ssl-installation/ubuntu-server-with-apache2-openssl.htm

Generating a RSA private key

openssl req -new -newkey rsa:2048 \
-nodes -out cherkavideveloper.csr \
-keyout cherkavideveloper.key \
-subj "/C=DE/ST=Bavaria/L=München/O=cherkavi/CN=cherkavi developer" \

SSLCertificateFile "/path/to/www.example.com.cert" SSLCertificateKeyFile "/path/to/www.example.com.key"

tools:

• ETL
• ETL
• web management - atomicproject.io, cockpit
  • install
  • guide
  • after installation
  • use your own user/password

virtual machines

• images
• app with infrastructure

mapping keys, keymap, assign actions to key

show key codes

xmodmap -pke

remap key 'Druck' to 'Win'

xmodmap -e "keycode 107 = Super_L"

to reset

setxkbmap

save to use during each reboot

create file '~/.Xmodmap'

find key code

xev | grep keysym

key code, scan code, keyboard code

sudo evtest 
sudo evtest /dev/input/event21

remap [hjkl] to [Left, Down, Up, Right], cursor hjkl

content of $HOME/.config/xmodmap-hjkl

keycode 66 = Mode_switch
keysym h = h H Left 
keysym l = l L Right
keysym k = k K Up
keysym j = j J Down

execute re-mapping, permanent solution

# vim /etc/profile
xmodmap $HOME/.config/xmodmap-hjkl

remap reset, reset xmodmap

setxkbmap -option

terminal title

set-title(){
  ORIG=$PS1
  TITLE="\e]2;$@\a"
  PS1=${ORIG}${TITLE}
}

set-title "my title for terminal"

code/decode

base64

base64 cAdvisor-start.sh | base64 --decode
echo "just a text string" | base64 | base64 --decode

md5

md5sum

hardware serial numbers, hardware id, hardware version, system info

sudo dmidecode --string system-serial-number
sudo dmidecode --string processor-family
sudo dmidecode --string system-manufacturer
# disk serial number
sudo lshw -class disk

equipment system devices

inxi -C
inxi --memory
inxi -CfxCa

pdf

convert pdf to image

convert -geometry 400x600 -density 100x100 -quality 100 test-pdf.pdf test-pdf.jpg

bar code create into pdf

barcode -o 1112.pdf -e "code39" -b "1112" -u "mm" -g 50x50

qr code online generator

http://goqr.me/api/doc/create-qr-code/
http://api.qrserver.com/v1/create-qr-code/?data=HelloWorld!&size=100x100

bar code finder

apt install zbar-tool
zbarimg <file>

pdf file merge, pdf join

gs -dBATCH -dNOPAUSE -q -sDEVICE=pdfwrite -sOutputFile=finished.pdf test-pdf2.pdf test-pdf3.pdf test-pdf4.pdf

doc to pdf, convert to pdf

libreoffice --headless --convert-to pdf "/home/path/Dativ.doc" --outdir /tmp/output

zip

unzip bz2

bzip2 -dc ricochet-1.1.4-src.tar.bz2 | tar xvf -

console and clipboard

alias clipboard="xclip -selection clipboard" 
alias clipboard-ingest="xclip -selection clipboard"
function clipboard-copy-file(){
    xclip -in -selection c $1
}
alias clipboard-print="xclip -out -selection clipboard"

screenshot, copy screen

screenshot(){
	file_name="/home/user/Pictures/screenshots/screenshot_"`date +%Y%m%d_%H%M%S`".png"
	scrot $file_name -s -e "xdg-open $file_name"
}

printer managing ( add/remote/edit )

http://cups.org - printer installation http://localhost:631/admin in case of authorization issue:

/etc/cups/cupsd.conf and changed the AuthType to None and commented the Require user @SYSTEM:

<Limit CUPS-Add-Modify-Printer CUPS-Delete-Printer CUPS-Add-Modify-Class CUPS-Delete-Class CUPS-Set-Default CUPS-Get-Devices>
AuthType None
# AuthType Default
# Require user @SYSTEM
Order deny,allow
</Limit>

and restart the service

sudo service cups restart

kernel related messages

dmesg --level=err,warn
dmesg --follow
# save all messages /var/log/dmesg
dmesg -S

disk usage

df -ha
# with visualization
ncdu

create startup disk, write iso image, usb stick, bootable drive

# list of all hard drives, disk list
sudo lshw -class disk -short
# write image
sudo dd bs=4M if=/home/my-user/Downloads/archlinux-2019.07.01-x86_64.iso of=/dev/sdb status=progress && sync

create usb live with persistence, usb persistence, stick persistence

sudo add-apt-repository universe
sudo add-apt-repository ppa:mkusb/ppa
sudo apt-get update
sudo apt install --install-recommends mkusb mkusb-nox usb-pack-efi
mkusb
# Install, persistent live, upefi

split usb drive, split disk

# detect disks
sudo lshw -class disk -short
sudo fdisk -l

# format drive
DEST_DRIVE=/dev/sdb
sudo dd if=/dev/zero of=$DEST_DRIVE  bs=512  count=1
# sudo mke2fs -t xfs $DEST_DRIVE

# split drive, split disk, split usb
sudo parted $DEST_DRIVE

print
rm 1
rm 2

mklabel kali
msdos

mkpart primary ext4 0.0 5GB
I

mkpart extended ntfs 5GB -1s

print 
set 1 boot on
set 2 lba on
quit

sudo fdisk -l

Elapsed time between two commands

STARTTIME=$SECONDS
sleep 2
echo $SECONDS-$STARTTIME

STARTTIME=`date +%s.%N`
sleep 2.5
ENDTIME=`date +%s.%N`
TIMEDIFF=`echo "$ENDTIME - $STARTTIME" | bc | awk -F"." '{print $1"."substr($2,1,3)}'`

language translator

sudo apt-get install translate-shell
trans -source de -target ru -brief "german sentance"

video

join mp4 fusion mp4

ffmpeg -i video.mp4 -i audio.mp4 output.mp4

sound

join files

sox 1.wav 2.wav 3.wav 4.wav output.wav
ffmpeg -i 1.wav -i 2.wav -i 3.wav output.wav

copy users, import/export users

sudo awk -F: '($3>=LIMIT) && ($3!=65534)' /etc/passwd > passwd-export
sudo awk -F: '($3>=LIMIT) && ($3!=65534)' /etc/group > /opt/group-export
sudo awk -F: '($3>=LIMIT) && ($3!=65534) {print $1}' /etc/passwd | tee - | egrep -f - /etc/shadow > /opt/shadow-export
sudo cp /etc/gshadow /opt/gshadow-export

Sqlite

copy scripts to database

# sudo apt-get install sqlite3
cat src/scripts.sql | sqlite3 src/db.sqlite

calculcate size of files by type

find . -name "*.java" -ls | awk '{byte_size += $7} END{print byte_size}'

calculcate size of files by type, list of files, sort files by size

du -hs * | sort -h

calculator

expr 30 / 5
myvar=$(expr 1 + 1)

sudo without password, apple keyboard, sudo script without password

echo 'password' | sudo -S bash -c "echo 2 > /sys/module/hid_apple/parameters/fnmode" 2>/dev/null

default type, detect default browser, mime types

xdg-mime query default x-scheme-handler/http

open in default browser

x-www-browser http://localhost:9090

open file with default editor, default viewer, with more appropriate viewr

rifle <path to file>

install haskell

sudo apt-get install haskell-stack
stack upgrade
stack install toodles

get started with hackell

shell examples

byobu

sudo apt install byobu

check architecture

dpkg --add-architecture i386
dpkg --print-architecture
dpkg --print-foreign-architectures

move mouse, control X server

apt-get install xdotool
# move the mouse  x    y
xdotool mousemove 1800 500
# left click
xdotool click 1

calendar, week number

gcal --with-week-number