Make a Bash alias that takes a parameter?

Bash alias does not directly accept parameters. You will have to create a function.

alias does not accept parameters but a function can be called just like an alias. For example:

myfunction() {
    #do things with parameters like $1 such as
    mv "$1" "$1.bak"
    cp "$2" "$1"
}


myfunction old.conf new.conf #calls `myfunction`

By the way, Bash functions defined in your .bashrc and other files are available as commands within your shell. So for instance you can call the earlier function like this

$ myfunction original.conf my.conf

Refining the answer above, you can get 1-line syntax like you can for aliases, which is more convenient for ad-hoc definitions in a shell or .bashrc files:

bash$ myfunction() { mv "$1" "$1.bak" && cp -i "$2" "$1"; }

bash$ myfunction original.conf my.conf

Don't forget the semi-colon before the closing right-bracket. Similarly, for the actual question:

csh% alias junk="mv \\!* ~/.Trash"

bash$ junk() { mv "$@" ~/.Trash/; }

Or:

bash$ junk() { for item in "$@" ; do echo "Trashing: $item" ; mv "$item" ~/.Trash/; done; }