paradox-echo

¯\_(ツ)_/¯

notes

The details

Apache

Switch php versions
  1. sudo a2dismod php<version>
  2. sudo a2enmod php<version>
  3. sudo service apache2 restart

archive

gzip

create gzip file

gzip file
tar

Create archive without absolute paths

tar -czf new_archive.tar.gz -C folder .

Extract to a specific folder

tar –xvzf documents.tar.gz –C /home/user/destination

cat

concatenate files and print on the standard output

cat <file>

cat access logs, pipe to [[grep]] to extract uniq IPs in order

cat access.log | grep -E -o "(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)" | sort -u -V

curl

get header info

curl -ILv https://your_domain
  • I, --headShow document info only
  • L, --location Follow redirects
  • -v, --verbose Make the operation more talkative

test for gzip

curl -H "Accept-Encoding: gzip" -I http://your_domain/some_text_file

date time

Time zone

list times zones

timedatectl list-timezones

set time zone

sudo timedatectl set-timezone Africa/Johannesburg

disk

DF

The ‘df’ command stands for “disk free” and is used to display information about the file systems on your Linux system. It provides a snapshot of disk usage, showing the total space, used space, available space, and the percentage of use for each mounted file system.

df -h /
DU (and NCDU)

The `du` command in Linux is a powerful utility that allows users to analyze and report on disk usage within directories and files.

du -h --max-depth=1 /path

Docker

Set up

Run Docker without sudo. Use usermod to add current username to the docker group.

sudo usermod -aG docker ${USER}

To apply the new group membership, log out of the server and back in, or type the following:

su - ${USER}
Images

List images

docker images

Remove image

docker rmi image_name_or_id
docker image rm image_id
Containers

List all containers

docker ps -a

List container IDs containers

docker ps -q

Stop all containers

docker stop $(docker ps -aq)
Volumes

List volumes

docker volume ls

Remove unused volumes

docker volume prune

firefox

changes to the about:config

scrollbar size
widget.non-native-theme.scrollbar.size.override = 20
widget.non-native-theme.scrollbar.style = 4

cookiebanner

cookiebanners.ui.desktop.enabled = true

find

find file with name
find . -type f -name <file name>
find all *.log files created in last 90 days except for last 7 days
find . -type f -name "*.log" -mtime +7 -mtime -90 -ls
  • search current directory + subdirectories for files (-type f):
  • with the .log extension (-name "\*.log")
  • that were last modified more than 7 days ago (-mtime +7)
  • but less than 90 days ago (-mtime -90)
  • list (-ls) results
  • option: case insensitive search replace the -name "\*.log" with -iname "\*.log"
find delete all *.log files created in last 90 days except for last 7 days
find . -type f -name "*.log" -mtime +7 -mtime -90 -delete

git

rebase
git rebase <base>
get the remote URL
git ls-remote --get-url

grep

find string in files recursively and show line numbers
grep -rn <search string> .
grep -rn --exclude-dir=<directory name> <search string> .

keys

generate ssh key
ssh-keygen
  • set key type as rsa|dsa|ecdsa|ed25519 
    -t rsa
  • set bit length to 4096 
    -b 4096
Convert PPK to id_rsa
puttygen example.ppk -O private-openssh -o example_id_rsa
Convert id_rsa to PPK
puttygen example.ppk -O private-openssh -o example_id_rsa

unlink

unlink <file name>

mysql (or my squirrel)

login with user name and password

mysql -u database_user -p
mysql -h database_host -u database_user -p

export a database

mysqldump -u root -p database_name > database_name.sql

import database

mysql -u root -p database_name < file.sql

create user

  1. CREATE USER 'newuser'@'localhost' IDENTIFIED BY 'password';
  2. GRANT ALL PRIVILEGES ON * . * TO 'newuser'@'localhost';
  3. FLUSH PRIVILEGES;

show users

select * from mysql.user;

update

UPDATE _table_name_ SET _column1_ = _value1_, _column2_ = _value2_, ...  WHERE _condition_;

rsync

sync

rsync -az --info=progress2 / /
  • a:recursively transferred in "archive" mode, ensures symbolic links, devices, attributes, permissions, ownerships, etc.
  • z: enable compression
  • --info=progress2: statistics based on the whole transfer

sed

find and replace string in file

sed -i -e 's/abc/XYZ/g' /tmp/file.txt

Short URLs

  • bit.ly - add + at the end
  • cutt.ly - add @
  • tiny.cc - add =
  • tinyurl.com - add preview. before tinyurl.com

Space and size

disk space

df -h /

folder size

du -h --max-depth 1 /
du -h -d 1 /

ssh

ssh -i <identity_file> -t <user>@<host> "<command>"
  • `-t` Force pseudo-terminal allocation. This can be used to execute arbitrary screen-based programs on a remote machine

text

sort

Dedupe text file:

sort -u input-file output-file
  • -u, --unique
  • with -c, check for strict ordering; without -c, output only the first of an equal run

wget

Output response of url to file and print server response

wget -O <output file> -S <url>
wget -SO- -T 5 -t 1 https://example.com