How to pass command line arguments to a shell alias?

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How do I pass the command line arguments to an alias? Here is a sample:

alias mkcd='mkdir $1; cd $1;'

But in this case the $xx is getting translated at the alias creating time and not at runtime. I have, however, created a workaround using a shell function (after googling a little) like below:

function mkcd(){
  mkdir $1
  cd $1
}

Just wanted to know if there is a way to make aliases that accept CL parameters.
BTW - I use 'bash' as my default shell.

11 Answers

You found the way: create a function instead of an alias. The C shell has a mechanism for doing arguments to aliases, but bash and the Korn shell don't, because the function mechanism is more flexible and offers the same capability.

You cannot in ksh, but you can in csh.

alias mkcd 'mkdir \!^; cd \!^1'

In ksh, function is the way to go. But if you really really wanted to use alias:

alias mkcd='_(){ mkdir $1; cd $1; }; _'

To quote the bash man page:

There is no mechanism for using arguments in the replacement text. If arguments are needed, a shell function should be used (see FUNCTIONS below).

So it looks like you've answered your own question -- use a function instead of an alias

This works in ksh:

$ alias -x mkcd="mkdir \$dirname; cd \$dirname;"
$ alias mkcd
mkcd='mkdir $dirname; cd $dirname;'
$ dirname=aaa 
$ pwd
/tmp   
$ mkcd
$ pwd
/tmp/aaa

The "-x" option make the alias "exported" - alias is visible in subshells.

And be aware of fact that aliases defined in a script are not visible in that script (because aliases are expanded when a script is loaded, not when a line is interpreted). This can be solved with executing another script file in same shell (using dot).

An empty alias will execute its args:

alias DEBUG=
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