List of basic commands on a terminal or command-line.
ls-- list the current directory contentspwd-- output the current directory pathcd-- change directory pathopen-- opens the file on the ui
Lets try it out!
- List your current directory path.
Example:
❯ pwd
/Users/jyang
- Now list everyting in that path.
❯ ls
Applications Documents Library Music Public go pod.yaml
Desktop Downloads Movies Pictures github p_creds
If you add the -l parameter specific to ls it will organize the output into a list.
❯ ls -l
total 16
drwx------@ 6 jyang staff 192 Apr 17 2020 Applications
drwx------@ 14 jyang staff 448 Mar 3 22:40 Desktop
drwx------@ 27 jyang staff 864 Mar 3 18:07 Documents
drwx------@ 37 jyang staff 1184 Mar 1 15:14 Downloads
drwx------@ 77 jyang staff 2464 Jan 15 20:25 Library
drwx------+ 6 jyang staff 192 Mar 10 2020 Movies
drwx------+ 4 jyang staff 128 Feb 9 2020 Music
drwx------+ 6 jyang staff 192 Sep 4 15:58 Pictures
drwxr-xr-x+ 4 jyang staff 128 Feb 5 2020 Public
lrwxr-xr-x 1 jyang staff 16 Feb 5 2020 github -> Documents/github
lrwxr-xr-x 1 jyang staff 12 Feb 14 2020 go -> Documents/go
-rw------- 1 jyang staff 116 May 5 2020 p_creds
-rw-r--r-- 1 jyang staff 279 Apr 30 2020 pod.yaml
- Now try changing your directory and explore what files exist in each directory.
❯ ls -l
total 595936
drwxr-xr-x 8 jyang staff 256 May 23 2020 AustinYang Can Delete
-rw-r--r--@ 1 jyang staff 79279 Sep 4 16:06 Photo on 9-4-20 at 4.06 PM #3.jpg
-rw-r--r--@ 1 jyang staff 131095 Sep 7 13:49 Photo on 9-7-20 at 1.49 PM #2.jpg
-rw-r--r--@ 1 jyang staff 1931339 Mar 20 2020 Screen Recording 2020-03-20 at 6.24.31 PM.mov
-rw-r--r--@ 1 jyang staff 287550206 Mar 20 2020 Screen Recording 2020-03-20 at 6.24.55 PM.mov
-rw-r--r--@ 1 jyang staff 23101 Feb 10 2020 Screen Shot 2020-02-10 at 4.23.17 PM.png
-rw-r--r--@ 1 jyang staff 22961 Mar 3 2020 Screen Shot 2020-03-03 at 11.01.13 PM.png
-rw-r--r--@ 1 jyang staff 22099 Mar 8 2020 Screen Shot 2020-03-08 at 11.16.40 PM.png
drwxrwxrwx 317 jyang staff 10144 Jun 27 2020 kongandlila
-rw-r--r--@ 1 jyang staff 341 Mar 4 23:03 test.yaml
- Then print out your path to see the difference.
❯ pwd
/Users/jyang/Desktop
- Try to go back to where you started.
❯ pwd
/Users/jyang/Desktop
❯ cd /Users/jyang
❯ pwd
/Users/jyang
Sometimes it takes longer to navigate back one directory above or to go back to $HOME. Here are some technques to master navagation.
Example 1 -- great to use when you're wanting to go back just a few directory/directories.
❯ pwd
/Users/jyang/Desktop
❯ cd ..
❯ pwd
/Users/jyang
❯ cd ../..
❯ pwd
/
Example 2 -- good to use when you want to go back to your home directory.
❯ pwd
/
❯ cd
❯ pwd
/Users/jyang
Example 3 -- best practice to use ~/ which allows you to start at the beginning of your home directory. Sometimes some linux/unix based operating systems don't understand tilda ~.
❯ pwd
/Users/jyang/Desktop/kongandlila
❯ cd ~/
❯ pwd
/Users/jyang
Example 4 -- best practice to use in your script so that you know exactly where you're starting.
❯ pwd
/Users/jyang/Desktop
❯ cd $HOME
❯ pwd
/Users/jyang
These commands will benefit you in the long run as you become more familiar with the command-line. Computers with a GUI (graphic user interface) carry a lot of work and consumes a lot of resources; that being compute, memory and storage. Using the command-line is very accurate and very powerful. You can manipulate data (files or contents in a file) on a very largers scale.
Bonus -- open a file or directory.
Businesses want to run efficently. In theory having a server with GUI consumes more resources and time. Just think about it, although graphics may consume more compute, memory and storage its more work for a computer, more electricity to keep it thinking and more electricity means more money. When you have hundrends and even thousands of servers with these extra GUI the all stack up.
One of the perks of a command-line on servers like Linux/Unix is the ability to run scripts. Scripts are kind of like a programming language but different in that they use command-line and system instructions. You can write them in a file from top to bottom and it will run the directions from top to bottom.
On Windows Servers, especially older operating systems, can run on scripts (often in the form of a file called .exe) but are notorious for their GUI which is fatiguing sometimes because you have to constantly interact with it and if the connection is poor/slow/unresponsive using it becomes frustrating. I will say Windows Server do manage users and access a lot better but for development they are a nightmare.
This managing tool/application is called Active Directory; AD for short.
Knowing how to navigate on the command-line will help you become a better coder (aka programmer, developer). Some of the tools you will commonely use to help you stay in sync with your team is heavly command-line based.
whoami-- output user namewho-- outouts who is currently on the computer as a userid-- outputs user informationgroups-- outputs group associated with userchmod-- change access to a file or directorychown-- change owner to a file or directorydf-- output disk/storage capacitydate-- outout date and computer time-zonetime-- output how long computer has been runnning
man-- every command has a manual/instructionsps-- list process statusfind-- outputs every possible pathwhich-- locates the location of a commanduname-- outputs computer infonslookup-- looks for computer names via ip address and vice-versahost-- looks up dns name related to a ip address
curl-- transfer data from or to another computer or vice-versaprintenv-- outputs command-line environment variablegrep-- file pattern searchermount