Commands

  • man - show manual information about a command
  • sudo - do it as root (superuser)
  • apt - use interactively only (use apt-get in scripts)
  • sudo apt update - update all the sources for packages
  • sudo apt upgrade - upgrade all packages to latest version
  • apt search ^neo - search for all package starting with neo
  • sudo apt install neofetch - install neofetch and dependencies
  • sudo apt remove neofetch - remove neofetch
  • sudo apt autoremove - automatically remove unused packages
  • ls - list the files in the (current) directory
  • ls -al - list all the files including hidden (begin with .)
  • hostname - display name of host computer
  • pwd - print working directory
  • cd foo - change into the foo directory
  • cd, cd ~ - change back to the home directory
  • cd .. - change into the relative parent directory
  • cd ../.. - change into the relative parent of the parent directory
  • cd - - change to previous directory

  • cd / change to the root directory

  • ip a - show all IP addresses (ipconfig /all, on Windows)

  • clear - clears the screen
  • which ssh - display full path to ssh program
  • type ssh - display what type of thing it is
  • who - display who is logged in an how
  • id - display user and group names and ids for self
  • w - display logger version of who is logged in
  • whoami - print effective user name/ID
  • users - short name of all logged in users
  • last - summary of last logged in users
  • exit - exit the current program or login or shell
  • | less or | more - see scrolled output in terminal (q to quit)
  • <Ctrl>-c - interrupt whatever (exit)
  • <Ctrl>-d - send "end of data/file"
  • sudo apt install openssh-server - install ssh server (if not)
  • vboxmanage startvm <VMNAME> --type headless - start vm headless
  • vboxmanage list runningvms - list running vms
  • vboxmanage list vms - list all vms
  • vboxmanage controlvm <VMNAME> poweroff - power off headless vm
  • vim - basic vim https://rwx.gg/visurvive

  • nano - just so you understand nano editor is a thing

  • ip -c a - lookup IP addresses

  • set -o noclobber - stop from blowing away files
  • mv foo other - change file/directory foo name to other (or move)
  • mv -i foo other - change file name but protect against overwrites
  • cp foo other - copy file/directory foo name to other (or move)
  • cp -ar foo other - copy all foo to other keeping timestamp
  • scp foo target: - copy foo from host to remote target home dir (def)
  • ls -ld (or with .) - look directory permission on current directory
  • stat foo - see all the details about the foo inode
  • chmod +x foo - make foo file executable by user, group, other
  • chmod o-r foo - make foo unreadable by other
  • chown rando foo - change ownership of foo to rando
  • chown -R jill:jill olddir - recursively change ownership/group
  • sudo su - - effectively login as root without logging out
  • sudo su - foo effectively login as foo
  • stat -c '%a' - to see octal permissions
  • cd - - change into previous directory
  • echo foo - write foo to standard output
  • cat foo - write content of foo file to standard output
  • which foo - print the full file path to the executable foo
  • ls -l $(which sudo) - list perms for sudo command
  • sudo adduser foo - interactively add a user named foo (not RedHat)
  • sudo deluser foo - interactively delete a user named foo (not RedHat)
  • sudo passwd foo - change the password for foo
  • passwd - change own password
  • touch - create new text file or update last modified time stat
  • rmdir foo - remove an empty foo directory
  • rm -rf foo - remove directory or file foo and everything in it
  • grep jill /etc/passwd - list only line containing jill

  • file foo - tell type of inode

  • find . - sort of the same as ls -l1

  • find . -ls - sort of the same as ls -l1
  • find . -name '???' - find files/dirs with three letter name
  • find . -path '.git' - find files/dirs with .git anywhere in path
  • head -5 foo - show top five lines of foo file
  • tail -5 foo - show bottom five lines of foo file
  • tac foo - reverse lines of foo file
  • wc -l - print count of lines
  • nl - add line numbers to output
  • tee /tmp/foo - both writes to a file foo and to stdout
  • > - (over) write to file
  • >> - append to file
  • | - connect stdout to stdin
  • < - send file to stdin
  • lolcat - colorize things

  • cowsay - fun way to show output

  • ssh-keygen -f key -N '' - generates a 'key' and 'key.pub' for ssh connections. key.pub is supplied to what you want to connect to. Then connect to remote system over ssh with ssh -i key username@ip.ip.ip.ip