如何在bash脚本（Ubuntu 17.04）中正确设置别名？

Question

I have this script called menal in my ~/bin directory:

#!/bin/sh

alias mendir='cd ~/projects/myproject'

It has executable property and I expect that when I run it it sets an appropiate alias for cd command for the terminal session. But it doesn't. When I type $ menal in terminal it shows no error, but when I try $ mendir after that I get

No command 'mendir' found, did you mean:
 Command 'menhir' from package 'menhir' (universe)
mendir: command not found

When I type

$ alias mendir='cd ~/projects/myproject'
$ mendir

in terminal, it works.

What am I doing wrong? Is it a script scope issue or something?

Answer 1

Yes, it's a scope problem. Calling it the following way won't produce the result you expect:

./bin/menal

If you want the alias to persist, use source :

source ./bin/menal

Answer 2

You can add it to your .bash_profile .

alias mendir='cd ~/projects/myproject'

then do source ~/.bash_profile

It should create the alias and also will work on every login.