Commands

• cat - contatenate
• tac - concatenate in reverse

column command

The column utility formats its input into multiple columns.

printf "a:b:c\n1::3\n" | column -t -s ':'

Note that this output is different from one that is printed in terminal. Strange… Below is the terminal output.

uuidgen universal unique id generator

Generate unique ID’s

script Records terminal

man script
man scriptreplay

Example

script --timing=file.tm script.out
# Write some scripts
# Exit with `exit` or `^d`
scriptreplay --timing file.tm --typescript script.out

reset Recover a borked terminal

Count number of files in a directory

ls -1 | wc -l

Building from source

./configure
./configure --prefix=$path

Redirections

2>&1
2>&1 > /dev/null
>
>/dev/null
>>

Keymaps

Ctrl-c
Ctrl-d
Ctrl-l

cp

cut

less

linux

seq

paste

pstree

du

rsync

sed

ssh

vifm

zip

Readline

• C-x C-e to edit current commant in default text editor
• or v in vi mode

ldd Print shared libraries

This command can be used to find all the shared library or libraries of a program

ldd /usr/bin/vim

<2022-07-29 Fri> To check if a library is present ldconfig -p

https://serverfault.com/a/513938

ldconfig -p | grep libjpeg

Cronie

• https://askubuntu.com/questions/978382/how-can-i-show-notify-send-messages-triggered-by-crontab
• https://fedoramagazine.org/scheduling-tasks-with-cron/

sudo dnf install cronie

Unsorted

who
killall process_name(or)pid
alias
apropos
apt
apt-get
bc
cal
cat
cd
clear
chsh
date
df
diff
file
find
find -name "*name*"
fish
free
git add *
git commit -m "stuff"
git pull
git push
git status
git update
grep
grep string -r *; # This will follow symbolic links
grep string -r .; # This doesnot follow symbolic links
grep string -r; # same as next command
grep string file_name
head
help
hg add *
hg commit -m "stuff"
hg import --no-commit file.patch
hg pull
hg push
hg status
hg update
info
kill
kill -9
killall
less
lolcat
ls
lsb_release -a
make
make clean
make install
man
pushd popd
pwd
readlink -f
realpath
reboot
rename
rev
rsync
rsync -CazhPvu
sed
sh
sort
ssh -Y
ssh -x
ssh-copy-id -i .ssh/id_rsa.pub USER@HOST
stow
sudo apt install
sudo apt list
sudo apt update
sudo apt upgrade
tac
tail
tee
time
tmux
tmux attach
touch
tree
type
uname -a
uniq
unzip file.zip -d dir_ext
w
wall
wc
wc -l
wget
whatis
which
yes
zsh
tftp DOWNLOAD name.txt
tftp DOWNLOAD name.txt .; # This does not work. '.' will make the downloaded file 0 bytes
lshw; # List hardware
ls -1 | wc -l # Count number of files in a directory

cat

locate

make

Manual

https://www.gnu.org/software/make/manual/make.html#Rule-Introduction

Usage

Under current directory with make file targets

make target

Include other paths / directories

make -I dir -I dir2 ... target

Others

Create a desktop icon on Ubuntu or Debian based systems

Produce high cpu load

openssl speed -multi $(grep -ci processor /proc/cpuinfo)

Gnome Notification

https://stealthcopter.com/blog/2010/02/utilising-the-notification-system-in-kde-or-gnome-in-bash-scripts-ubuntu-9-10-linux/

Adding a user in Linux

sudo user add -m <username>

Note the -m option, this creates the /home/ directory

To delete a user

sudo userdel <username>

Useful Tools

https://myrepos.branchable.com/

https://nixos.org/download.html

curl -L https://nixos.org/nix/install | sh
nix-env -if https://github.com/jwoudenberg/shy/archive/main.tar.gz
shy

strace - trace sys calls

https://github.com/phyver/GameShell

Documentations and Books

• https://www.die.net/
• https://linux.die.net/Linux-CLI/index.html
• https://github.com/you-dont-need/You-Dont-Need-GUI