How to get name of alias that invoked bash script

Question

$0 expands to the name of the shell script.

$ cat ./sample-script
#!/bin/bash
echo $0
$ chmod 700 ./sample-script
$ ./sample-script
./sample-script

If the shell script is invoked via a symbolic link, $0 expands to its name:

$ ln -s ./sample-script symlinked-script
$ ./symlinked-script
./symlinked-script

How could I get the name of an alias? Here `$0' expands again to the filename:

$ alias aliased-script=./sample-script
$ aliased-script
./sample-script

Answer 1

Aliases are pretty dumb, according to the man page

...Aliases are expanded when a command is read, not when it is executed...

so since bash is basically just replacing a string with another string and then executing it, there's no way for the command to know what was expanded in the alias.

Answer 2

I imagine you already know this, but for the record the answer is: you need cooperation by the code implementing the alias.

alternate_name () {
  MY_ALIAS_WAS=alternate_name real_name "$@"
}

or, if you really want to use the superseded alias syntax:

alias alternate_name="MY_ALIAS_WAS=alternate_name real_name"

...and then...

$ cat ~/bin/real_name
#!/bin/sh
echo $0, I was $MY_ALIAS_WAS, "$@"

Answer 3

bash does not make this available. This is why symlinks are used to invoke multiplex commands, and not aliases.