Please follow and complete the free online Command Line Crash Course tutorial. This is a great, quick tutorial. Each "chapter" focuses on a command. Type the commands you see in the Do This section, and read the You Learned This section. Move on to the next chapter. You should be able to go through these in a couple of hours.
Make a cheat sheet for yourself: a list of commands and what they do, focused on things that are new, interesting, or otherwise worth remembering.
pwd: print where you are on the computer
hostname: display name of computer and network you’re on
mkdir: make a new folder (-p creates a whole path of files)
cd: change which folder you’re in (just cd goes to home directory. cd with folder/file name can go to that location below where you currently are. Use cd ../.. to go up two levels. Use cd /foldername to go up levels.)
ls: list the files and folders in the folder you’re currently in
rmdir: remove a folder (only when folder is empty. Use rm to delete files. Use rm -i to make sure you don’t accidentally delete something you need!)
pushd: save the location where you currently are and go somewhere else
popd: return to last location pushed
cp: copy a file or folder (cp -r copies folders with files in them.)
mv: move a file or folder (rename)
less: page through a file (while in file, spacebar pages down, w pages up, q quits)
cat: print the whole file (Cmd-d to exit)
rm: remove file (rm -rf deletes folder and contents. Careful here.)
xargs: execute arguments
find: find files (find STARTDIR -name “WILDCARD.filetype” -print)
grep: find inside files (Use quotes to find words.)
man: read a manual page
apropos: find what manual page is appropriate
env: look at your environment
echo: print some arguments
export: export/set new environment variable (unset to remove)
exit: exit the shell
xargs: execute arguments
chmod: change permission modifiers
chown: change ownership of a file
sudo: run programs with the security privileges of another user, including the super user.
#Other notes: Need to include quotes around folders and files with spaces in the name
$|$ Uses output from command on left as input for the command on the right
$>$ Takes the output from the command on the left and writes it into the file on the right
$<$ Takes the input from the file on the right and sends to the program on the left.
$>>$ Takes the output from the command on the left and appends it to the file on the right
- wildcard
What does ls do? What do ls -a, ls -l, and ls -lh do? What combinations of those flags are meaningful?
lslists all the files and folders contained in the folder you are currently in.
ls -awill list the same files and folders, plus any hidden files (hidden files contain a dot)
ls -lwill list files and folders in long format. This includes permissions and date/time last modified, among other things.
ls -lhuses unit suffixes (Byte, KB, MB, GB, TB, PB) to display the file size to reduce number of digits shown
ls -lawill list all files and folders (including hidden ones) in long format.
ls -lhaorls -lahwill both give long format, with reduced file size, for all files and folders, including hidden ones.
What does xargs do? Give an example of how to use it.
xargsis used to pass the output of one command as an argument to another command. You could use it to rename a batch of files at one time.ls *.log | xargs -i mv {} {}_bkpwill take all log files and add _bkp to the end of the file names.