Bash alias with piping

Question

I'm not exactly sure what I'm doing wrong with this one. I'm trying to run the command

alias localip='ip -4 -o addr show eth0 | egrep -o '([[:digit:]]{1,3}\.){3}[[:digit:]]{1,3}' | head -n 1'

If I run the command

ip -4 -o addr show eth0 | egrep -o '([[:digit:]]{1,3}\.){3}[[:digit:]]{1,3}' | head -n 1

I get the result I expect, however, when trying to create an alias with the command, I get

-bash: syntax error near unexpected token `('

Any help would be appreciated. TIA.

Answer 1

You're nesting single quotes within single quotes. That doesn't work.

Try using "double quotes" in the inner expression.

Answer 2

I found it a much cleaner solution to just create a function and name your alias after the function, like this:

alias localip=GetLocalIP

function GetLocalIP()
{
   ip -4 -o addr show eth0 | egrep -o '([[:digit:]]{1,3}\.){3}[[:digit:]]{1,3}' | head -n 1
}