How to change argv[0] value in shell / bash script?

Question

The set command can be used to change values of the positional arguments $1 $2 ...

But, is there any way to change $0 ?

Answer 1

In Bash greater than or equal to 5 you can change $0 like this:

$ cat bar.sh
#!/bin/bash
echo $0
BASH_ARGV0=lol
echo $0
$ ./bar.sh 
./bar.sh
lol

ZSH even supports assigning directly to 0:

$ cat foo.zsh
#!/bin/zsh
echo $0
0=lol
echo $0
$ ./foo.zsh 
./foo.zsh
lol