Essential Linux commands Every Dev should know !!

There are tons of commands in every Linux distro.some of the basic commands every developer should know.

1. Check current path of the directory

  pwd

2. Change to a directory

cd <directory name>

cd data , to enter/change to folder data.

3. List contents of a directory

ls 

ls data , will list files of data folder.
ls -a data , will also list hidden files in the data folder
ls -l data , will list files/folders in data folder with permission.
combining above two commands ls -la data will give you all files including hidden files with permission.

4. create a directory

mkdir 

mkdir data will create data directory in current location.
mkdir -p data/video will create data directory and a video folder inside.
mkdir -p data/{video,music} will create data directory and video,music folder inside.

5. view content of a file

cat 

cat hulk.txt , can view content of hulk.txt

6. edit a file

There are several ways we can edit file in Linux , most of the Linux distro will have vim editor. so we are looking into vim today.

vim <filename>

type i for insert mode , make changes to current file.
press ESC button then type :wq to save the file.

7. search

grep "pattern" file

grep "hulk" avangers.txt , will search for the
avangers.txt for the pattern "hulk".
grep -i "hulk" avangers.txt marvel.txt for case-insensitive search in multiple files.
grep -nr "hulk" data if you want to search a pattern in folder data.

8. find the difference between two files

diff command is used to find the difference between two files.

diff file1 file2

here we can understand difference between file1 and file2.

9. find files in the system

find -name hulk.txt

this command will find all the files named hulk.txt in the folder and sub-folder.

10. Changing permission of a file.

• 4 - read permission
• 2 - write permission
• 1 - execute permission
• 0 - no permission

chmod 755 hulk.txt

This gives all permission to file hulk.txt.
In 755
7 is user permission
5 is group permission
5 is others permission

for example if you want change permission/restrict permission to only for you

chmod 700 hulk.txt 

This is my first post , let me know how can i improve in upcoming posts