.bashrc loading aliases from different file

Question

I have a .bashrc file, which I want to setup so it reads aliases from an .aliases file and sets them up.

Currently I have:

# User specific aliases and functions
while read alias_line
do
        echo `alias ${alias_line}`
done < .aliases

But upon login I get:

-bash: alias: -fu: not found -bash: alias: $USER": not found

-bash: alias: -lart": not found

The .aliases file is like this:

psu="ps -fu $USER" ll="ls -lart"
pico='nano'

Answer 1

When you use alias ${alias_line}, the variable is broken up at spaces, ignoring quoting rules.

There are two ways you could fix it:

• Remove all quoting from the alias file:

  ll=ls -lart
  psu=ps -fu $USER
  

  and put the variable itself in quotes:

  alias "$alias_line"
  

  This works because in bash, ll="ls -lart" and "ll=ls -lart" are exactly equivalent.

• Alternatively (this is a better and more common way), have a file with alias commands, and use the . builtin (aka source) to import it.

  alias pico='nano'
  alias psu='ps x'
  alias ll='ls -lart'
  

  then in your ~/.bashrc:

  . ~/.aliases
  

The second method is better, since it does not limit you to aliases, but also allows defining functions, which are much more powerful.