get value of an alias in bash

Question

I recently switched from tcsh to bash, and I'm used to being able to do things like sudo `alias netstat` but since alias gives name=value in bash, I can't do this anymore. Is there an equivalent in bash, so I don't have to do sudo `alias netstat | sed -r "s/.*='(.*)'/\1/"`?

Wrap it in a function and add it to `.bashrc`. Problem solved. — Daniel Beck, Jan 01 '12 at 09:10

score 11 · Answer 1 · answered Jan 01 '12 at 13:00

Bash stores its list of aliases in the associative array BASH_ALIASES. The equivalent of sudo `alias netstat` is then sudo ${BASH_ALIASES[netstat]}. However, I would suggest the following instead, which works with builtin shell commands and deals correctly with quoting:

sudo bash -c "${BASH_ALIASES[netstat]}"

There's still a lot that won't work with this, like e.g. nested aliases.

score 2 · Accepted Answer · answered Jan 01 '12 at 13:24

2

You're trying to have bash expand aliases after sudo. You do not need to do it the exact same way; in fact, there is a far more convenient way in bash – add an alias for sudo that ends with a space...

alias sudo="sudo "

...and sudo netstat will be expanded automatically.

answered Jan 01 '12 at 13:24

u1686_grawity

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excellent, and `sudo \netstat` won't expand netstat's alias! – Jayen Jan 01 '12 at 13:41

get value of an alias in bash

2 Answers2