Useful-commands.md

UPDATED 2020.07.01

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Basic Ubuntu commands:

df shows disk usage, add -h to the end for human readable numbers
du shows disk usage per files, add -h to the end of for human readable numbers, give it a directory and it will spit out the files in that directory and the size of those files
ls lists everything in the directory that you are currently in or you can specify a directory
cd to change directory
cd ~ to go to your home directory
cd / to go to top most directory
cd ../ to go back a directory
mkdir creates a directory
rm deletes files + directories
touch creates files
nano is a text editor
cp copies files
mv moves files
cat outputs whats in the file you specify
sudo is superuser mode, all permissions - everything, you don't use this if you are using the root user as it already has all permissions but if you were using a user that wasn't root you'd use that
clear clears the terminal
zip, unzip and gzip do zippy things
uname -a prints info about the machine like OS version, kernel version, hostname, datetime etc
chmod changes the file/directory permissions, add -R to the end for it to change permissions for all files + directories in the directory you specify
chown changes the owner/group permissions for file/directory, add -R to the end for it to change owner/group for all files + directories in the directory you specify
passwd changes the password for the user you are currently logged into
su switches user to the user you specify
whoami outputs the name of the user you're currently logged into
ifconfig outputs the network configuration

There are also a few more basic commands like:

grep, wget, curl, ping, traceroute, cron, find, tail, kill, uptime

Looks for "string" inside of all files inside of "/path/"

grep -rnw '/path/' -e 'string'

Gets the size of files inside of "/path/", add "| sort -h" to the end for it to sort the output by largest file at the bottom

du -sh /path/

Screen commands:

Start session
screen -S <screen name> List sessions
screen -ls Detach from session
Ctrl + A then press D Attach to session
screen -r <screen name> To kill a session attached
Ctrl + A then type :quit To kill a session deattached
screen -X -S <screen name> quit To scroll in a session while attached
Ctrl + A then press ESC, then use arrow keys for up and down or mouse scroll wheel, hit Q or ESC to stop scrolling Ececute command detached
screen -S <screen name> -X eval 'stuff "COMMAND_HERE\015"' Writes everything in the scroll buffer to a file
Ctrl + A then type :hardcopy -h /path/FILE_NAME.txt