README.md

This mildly obfuscated and very obtuse script is probably the grossest thing I've ever written.

Requirements

1. The script must be made executable
2. bash must be installed
3. perl must be <= 5.10

How it works

The script is technically a bash script. This bash script calls perl on itself with the -P flag, which runs the C preprocessor over the source file, as well as the -x flag. The -x flag will only start parsing the file provided when it encounters a shebang-like that contains the string "perl". This is why the second shebang can look as gross and misleading as it does but still trigger execution of Perl.

I use Filter::sh to use bash to execute perl as a source filter. Writing my own filter in pure Perl is trivial, but this is grosser. The filter simply translates '()' to '.__o()'. As we'll see, __o() returns a string, and we use Perl's string concat operator to join the return value of __o()

Since my filter doesn't catch 'g()', I use a C preprocessor macro to do that replacement.

__o() is simple, as it calls a different function, o, unless it was passed an argument. If it was passed an argument ('al', in our case) it just returns it.

o on the other hand, returns the return value caller, which is a stringified version of the package that the current function was called from, in this case, o.

__g() is a much simpler function. It grabs the symbol table from the o package, grabs the second symbol (__g() itself), and then does a substring into that symbol name ("g") and returns it.