Like most users, I have a bunch of aliases set up to give a default set of flags for frequently used programs. For instance,
alias vim='vim -X'
alias grep='grep -E'
alias ls='ls -G'
The problem is that if I want to use which
to see where my vim
/grep
/ls
/etc is coming from, the alias gets in the way:
$ which vim
vim: aliased to vim -X
This is useful output, but not what I'm looking for in this case; I know vim
is aliased to vim -X
but I want to know where that vim
is coming from.
Short of temporarily un-defining the alias just so I can use which
on it, is there an easy way to have which
'unwrap' the alias and run itself on that?
Edit: It seems that which
is a shell-builtin with different behaviors across different shells. In Bash, SiegeX's suggestion of the --skip-alias
flag works; however, I'm on Zsh. Does something similar exist there?
Best Answer
which
is actually a bad way to do things like this, as it makes guesses about your environment based on$SHELL
and the startup files (it thinks) that shell uses; not only does it sometimes guess wrong, but you can't generally tell it to behave differently. (which
on my Ubuntu 10.10 doesn't understand--skip-alias
as mentioned by @SiegeX, for example.)type
uses the current shell environment instead of poking at your config files, and can be told to ignore parts of that environment, so it shows you what will actually happen instead of what would happen in a reconstruction of your default shell.In this case,
type -P
will bypass any aliases or functions:You can also ask it to peel off all the layers, one at a time, and show you what it would find:
(Expanding on this from the comments:)
The problem with
which
is that it's usually an external program instead of a shell built-in, which means it can't see your aliases or functions and has to try to reconstruct them from the shell's startup/config files. (If it's a shell built-in, as it is inzsh
but apparently notbash
, it is more likely to use the shell's environment and do the right thing.)type
is a POSIX-compliant command which is required to behave as if it were a built-in (that is, it must use the environment of the shell it's invoked from including local aliases and functions), so it usually is a built-in.It isn't generally found in
csh
/tcsh
, although in most modern versions of thosewhich
is a shell builtin and does the right thing; sometimes the built-in iswhat
instead, and sometimes there's no good way to see the current shell's environment fromcsh
/tcsh
at all.