Another basic linux command line cheatsheet

Using the shell

# print the help
command --help

# ssh commands (use --help)
ssh      connect using ssh -pxxxx username@xx.xx.xx.xx
scp      ssh copy
rsync    remote sync

# common shell commands (use --help)
ls       list
cd       change directory
cp       copy
mv       move
rm       remove
mkdir    make directory
touch    create or reset date of creation
chown    change owner
chmod    change modification rights
tar      archive
gzip     zip (also : bzip2, 7zip)
pwd      path of current working directory
ln       create a link
vim      text editor

# manage packages (Ubuntu)
apt-get update          update the packages list
apt-get upgrade         upgrade all packages
apt-get install xxx     install the package xxx
apt-get remove xxx      keep the package config
apt-get purge xxx       also delet the package config
apt-cache policy xxx    read package infos
dpkg -l | grep xxx      see all packages with xxx in the name

# users
adduser username        add a new user
adduser username sudo   give the user sudo rights
passwd username         change user password

# manage
ps          print all processus
pstree      idem, displayed as a tree
kill        kill a processus
shutdown    shutdow the server (!)
du          disk usage
df          disk free
top         most ressources demanding processus
free        free memory
echo        display var content 
echo $PATH  display current directory
which       see where a command is installed

# Redirects
less file1 > file2            copy a file
echo words >> file.txt        add words to a file
ls > file.txt                 replace text in the file by the ls command output
ls >> file.txt                append text in the file with the ls command output
less < fichier.txt            get a file content

# Pipes
ps aux | grep bash            launch a second command using the output of the first

# Alias
alias mycommand="command1 command2"
mycommand filename