How to create an folder path alias on ubuntu EC2 instance?

Question

ubuntu 18.04 on AWS

I followed an answer on stackoverflow to create a path alias:

nano ~/.bashrc

alias myfolder='/home/xxx/pms'

When I try to cd

cd myfolder

I get:

No such file or Directory

But if I use the path it works.

I am not sure what the issue here is.

TIA

Answer 1

What you're trying

You may be thinking of the term alias as defined and used in Mac OS.

For ubuntu the command alias does something totally different. The command you have used is for creating new commands so you don't have to remember a longer command, or a longer command you type so much it is quicker to type the alias. For example, if I don't want to keep typing this command to launch a program:

java -jar /usr/local/bin/bfg-1.13.0.jar

You could create an alias called bfg in my Unix profile (or ~/.bashrc as you have) like this:

alias bfg='java -jar /usr/local/bin/bfg-1.13.0.jar'

From now on I can use bfg every time I want to run the java program.

What you really need

In Ubuntu what you're looking for is a symbolic link. A symbolic link is created with the ln command on Ubuntu (and all other Unix varieties). See the following example.

In the below example you can see a folder that already exists called pms in my home folder.

Thus its absolute path is /home/ubuntu/pms.

ubuntu@server:~$ ls -l
total 4
drwxrwxr-x 2 ubuntu ubuntu 4096 Mar 25 11:05 pms

Now I change to a mother directory where I want the link, what you are thinking of as an alias, and create the symbolic link with ln -s

ubuntu@server:~$ cd /tmp/
ubuntu@server:/tmp$ ln -s /home/ubuntu/pms myfolder

Now I'm able to change directory to this alias as you understand it.

ubuntu@server:/tmp$ cd myfolder/
ubuntu@server:/tmp/myfolder$ pwd
/tmp/myfolder

To be clear, an alias is a completely different thing in Unix & Linux land. The symbolic link I have made can be seen by listing the /tmp directory where I created it.

ubuntu@server:/tmp/myfolder$ cd /tmp
ubuntu@server:/tmp$ ls -l
total 16
lrwxrwxrwx 1 ubuntu ubuntu   16 Mar 25 11:06 myfolder -> /home/ubuntu/pms

The contents of the /tmp/myfolder are one and the same as /home/ubuntu/pms.