Where can I modify ls command to personalize with my preferred options?
 

Where can I find the file that I would modify in emacs, for instance, so that when I issue ls on terminal it invokes "ls -alphX" instead of just ls?

Thankyou in advance.

On Ubuntu (by default), you can put custom aliases in a file called ~/.bash_aliases .

In your case, then, you would put:
The next time you login to a shell, the change should be active.

BTW, I don't actually recommend changing ls. You could call it something else, like lsa. So:

Thankyou
 

Thankyou Mister, then should I do source bash after doing this to activate the changes?

solved
 

Thankyou Mister Williams, apparently it is already working as of writing the alias...

~/.bashrc sources ~/.bash_aliases, so it would work to source either of those files -- eboth end up re-reading the aliases.

question
 

It says I do not have permission even though I am already root

What is the command you are typing to get that message?

command
 

~/.bashrc sources ~/.bash_aliases

Oh okay. Yea, I meant that .bashrc includes .bash_aliases, so you can do one of:

or, alternatively,

Sorry for the confusing language.

thankyou
 

thankyou Sir