bash course exit 0 read -a export VAR not subshell profile subshells bashrc user top kill pid telnet 0 cat -vet 0 stdin, 1 stdout, 2 stderr pipeline stdout-)stdin grep -E '[A-Z][a-z]+\b' file.txt grep -l n c grep ^...$ #find any 3 chars sed -r s c a y I p whereis fdisk -l udev daemon chntpw su - vs su su - logs you in completely as root, whereas su makes it so you are pretending to be root. mount -o remount,rw / parted -k gpt gui uefi partitions )2tb (part 2) partitions primary extended logical have compiled your own kernel at some point, know how to trace syscalls, understand TCP, care about the difference between sysvinit/runit/systemd, etc man 7 signal trap kill term int substitution operators ${VAR:-word} pattern matching ${BLA#bla*} optarg man test pncopy strace -c ls hup vs kill var/log/messages centos rpm qa in ubuntu yum update apt.get update redhat satelite ubuntu landscape tools for deployment root.system.people sudo su ls --help show options cd...