In CentOS (different command from Ubuntu, I believe):

EDIT/WARNING:
* DO NOT MAKE A SYMBOLIC  LINK FROM YOUR HOME DIRECTORY (unless you are the only user).
* $HOME does NOT make the home directory dynamic, but will just permanently link to your current home directory (instead of whoever user)
* Make sure they are linked to /usr/local or your symbolic link wont work!

Let's say you have a file called "symbolic-link". It's stored in my home /usr/local directory. When you run it, it runs a script that echoes "Hi, i'm a working symbolic link."



I want it so that if i type symbolic-link anywhere, it will run the script.

1) Open terminal
2) Type ln -s $HOME/symbolic-link /usr/local/bin
2) Type in ln -s /usr/local/symbolic-link /usr/local/bin
NOTES:
ln -s (symbolic link)
/usr/local/symbolic-link (path to the script)
/usr/local/bin (file names in this folder turn into variables to launch from terminal)
3) Type symbolic-link and the script should run!

Things to know:
* /usr/local/bin is sort of like System32 .. auto installers, when keeping the default directories, will usually install a launch script into /usr/local/bin. Anything in this folder will run via commands.
* Symbolic link is just a shortcut placed in /usr/local/bin where the name of the file turns into an environmental variable to run the script.