Linux commands are kind of hard to remember, that is why working with terminal seems to be scary at the beginning. But it is perfectly OK, you start using the command line and you learn little by little though sometimes you forget the commands or the syntax of those commands! So you can do copy paste !
Linux commands are same for Linux mint, Kali Linux, Ubuntu and etc., you gonna need a cheat sheet to help you learn and remember them.
If you are not sure how to use these commands please feel free to see video I made. It really teaches you how to use terminal and Linux command line. (click here or see embedded at the bottom of the page )
Most Basic Commands
| cd | change folder |
| cd ~ | home |
| cd .. | parent folder |
| cd / | root folder |
| ls -lha | List directory (long)(human)(all) Equivalent to dir in windows |
| pwd | Current path |
| mkdir xyz | make directory xyz |
| mv ~/from /to/ | move file |
| ~/ and / are examples see cd you can use mv for rename! | |
| cp -ar ~/from ../to/ | copy all |
| ~/ and ../ are examples see cd |
Text Files :
| cat file.txt | Show content |
| cat file.txt | less | with paging |
| less file.txt | Show content with paging |
| echo ‘A string’ | Outputs : A string |
| echo $USER | Outputs user name |
| echo $HOME | Outputs home path |
Use it in bash scripts to give input to other command :
Ex : echo ‘Some text’ > xyz.txt
above make a file called xyz.txt with content some text
Remote Connection / File Copy
Linux does not have remote desktop as windows, but don’t worry Linux commands does the jobs perfectly. Sometimes you need to connect to another Linux server using terminal and/or copy file from one Linux system to another Linux system via network. there are applications that help you with that (specially if you are running windows and want to connect to a Linux system ) Putty for connection and WinSCP is for transferring file. But you can use Git bash in windows with these command (or you can run them directly in on Linux client)
Remote connection
| ssh [email protected] | remote connection |
| ssh -i key.pem [email protected] | with key |
Copy Files
| scp -i publicKey.pem myfile.txt remoteuser@remoteserver:/remote/folder/ | local 2 server |
| scp -i publicKey.pem remoteuser@remoteserver:/remote/folder/remotefile.txt localfile.txt | server2local |
Archive – Compress / Extract
| tar -cvf songs.tar ./folder | (create)(verbose)(filename) |
| -cvzf -gz (gzip) OR -cvjf -j (bzip2) | |
| tar -xvf songs.tar -C /target/directory | (extract)(verbose)(filename) |
| -xvzf (gzip) OR -xvjf (bz2) |
Permission In Linux
In Linux there is 3 type of access owner (single user) group and everyone. The weird thing is that owner does not has full permission but that is defined (r : read , w: write, x: execute). most people mix up two of Linux commands namely chmod and chown . the first one is to assign permission , the latter is for assign user and group (that has that permission)
NOTE : Don’t forget to restart your service when you change permissions and users (services that need access to files and folder like ftp, NginX, apache, K8s and …)
File Permissions (chmod)
| chmod -R 765 /dir |
| [owner][group][others] ===> Numbers ==> |
–rwxrwxrwx [owner][group][others]
| 0: No permission | 4: Read |
| 1: Execute | 5: Read and execute |
| 2: Write | 6: Read and write |
| 3: Write and execute | 7: Read, write and execute |
Assign user and group (chown)
chown user:group example.txt
Working with user
Here are Linux commands for working with users and groups
| adduser username // adduser username |
| addgroup groupname |
| usermod -a -G groupName userName |
Archive – Compress / Extract
Remember: Tar just put everything is a single file if you want to compress you need to combine it with gzip (or bzip)
| tar -cvf songs.tar ./folder | (create)(verbose)(filename) |
| -cvzf -gz (gzip) OR –cvjf -j (bzip2) | |
| tar –xvf songs.tar -C /target/directory (extract)(verbose)(filename) | (extract)(verbose)(filename) |
| -xvzf (gzip) OR -xvjf (bz2) |
Utilities
| curl www.me.com | browser |
| wget ww.com/file.tar | download |
| Nano xyz.txt | Editor |
| vim xyz.txt | Editor |
| htop | Get stats |
| lsblk | List Disks |
Make Private key single line
Sometimes you need to use private key as single line (for example when you are using it in settings) here is how to do it.
awk -v ORS='\\n' '1' private-key.pem | cat
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