pwd
print working directory
hostname
my computer's network name
mkdir
make directory
cd
change directory
ls
list directory
rmdir
remove directory
pushd
push directory
popd
pop directory
cp
copy a file or directory
mv
move a file or directory
less
page through a file
cat
print the whole file
xargs
execute arguments
find
find files
grep
find things inside files
man
read a manual page
apropos
find which man page is appropriate
env
look at your environment
echo
print some arguments
export
export/set a new environment variable
exit
exit the shell
sudo
DANGER! become super user root DANGER!
rm -rf <directory>
Forcefully remove directory recursively
rmdir
remove directory
ls -lR
list all directories in the path
...
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