Intro To 'ln' Command In Linux

2023-05-06 - By Robert Elder

     I use the 'ln' command to create links between files or directories:

ln -s target link_name

     These links can act like shortcuts:

     Here, I have a single file containing a list of to-do items in a file called 'todo.txt':

Todo items for the day:
- Check Hacker News 758943272 times
- Drink coffee
- Write software
- Get money

     I can use this 'ln' command to create a symbolic link named 'stuff.txt' that links to the original 'todo.txt' file.

ln -s todo.txt stuff.txt

     and now the current directory contains an entry for both 'todo.txt' and 'stuff.txt':

ls

stuff.txt  todo.txt

     Now, if I add some new text to my to-do list, I can see the changes through both the file itself and the symbolic link to the file:

echo "- Watch motivational YouTube videos for 3 hours" >> todo.txt

     checking 'todo.txt', I get the following:

cat todo.txt

Todo items for the day:
- Check Hacker News 758943272 times
- Drink coffee
- Write software
- Get money
- Watch motivational YouTube videos for 3 hours

     and in 'stuff.txt', I get the exact same thing:

cat stuff.txt

Todo items for the day:
- Check Hacker News 758943272 times
- Drink coffee
- Write software
- Get money
- Watch motivational YouTube videos for 3 hours

     If I run

ls -l

     I can see clearly that the symbolic link 'stuff.txt' points to 'todo.txt':

total 4
lrwxrwxrwx 1 robert robert   8 May  6 22:27 stuff.txt -> todo.txt
-rw-rw-r-- 1 robert robert 152 May  6 22:27 todo.txt

     I can even create a symbolic link to the 'todo.txt' file located from another directory:

mkdir ../stuff
cd ../stuff
ln -s ../docs/todo.txt todo_shortcut.txt

     Using the 'ls -l' command, I can view where the 'todo_shortcut.txt' symlink points to:

ls -l

lrwxrwxrwx 1 robert robert   16 May  6 22:34 todo_shortcut.txt -> ../docs/todo.txt

     and as expected, the 'todo_shortcut.txt' can be used to access the same file contents:

cat todo_shortcut.txt

Todo items for the day:
- Check Hacker News 758943272 times
- Drink coffee
- Write software
- Get money
- Watch motivational YouTube videos for 3 hours

     And that's why the 'ln' command is my favourite Linux command.