In the original version of the program:

/*
   python.c  - 27/01/2026
   by  bliako (bliako at cpan org)
   for https://perlmonks.org/?node_id=11167241

   Run it either with a Perl CLI and a Perl script,
   like you would normally do with perl script.pl,
   perl -e ... etc. or with a python CLI and a python script.
   If the script does not parse as valid Perl code,
   it will pass the CLI and the script to a python interpreter.
   CAVEAT: it will fallback to python if your script is Perl
           but has syntax errors.

   compile it with:
     gcc python.c -o python `perl -MExtUtils::Embed -e ccopts -e ldopt
+s`
*/

#include <EXTERN.h>               /* from the Perl distribution     */
#include <perl.h>                 /* from the Perl distribution     */

static PerlInterpreter *my_perl;  /***    The Perl interpreter    ***/

/* You gotta love Perl */
int main(int argc, char **argv, char **env)
{
    PERL_SYS_INIT3(&argc,&argv,&env);
    my_perl = perl_alloc();
    perl_construct(my_perl);
    PL_exit_flags |= PERL_EXIT_DESTRUCT_END;
    int ret = perl_parse(my_perl, NULL, argc, argv, (char **)NULL);
    if( ret ){
            perl_destruct(my_perl);
            perl_free(my_perl);
        // add here language detection logic,
        // various options available open source
        fprintf(stderr, "I guess it is &*^#$* pyton /sic/ ...\n");
        execvpe("/usr/bin/python", argv, env);
    }
    printf("It parses as Perl so I am running it ...\n");
    perl_run(my_perl);
        perl_destruct(my_perl);
        perl_free(my_perl);
    PERL_SYS_TERM();
    exit(EXIT_SUCCESS);
}
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