After running dtrace as $ sudo dtrace -n 'syscall::execve*:entry { printf("%s %s...

After running dtrace as

  $ sudo dtrace -n 'syscall::execve*:entry { printf("%s %s", execname, copyinstr(arg0)); }'

I had this output

    0  51617                     execve:entry sh ./quine
    1  51617                     execve:entry sh /bin/sh
    1  51617                     execve:entry sh /bin/cat

Altho this is the first time I use dtrace. I can try to run another command you can ask me to.

My login shell is the Bourne shell. However I tried bash, csh and tcsh too, it works, so it's probably the system level code that substitutes /bin/sh (maybe because it's my login shell?) to the interpreter.