I hope this is the right place for this. I have been messing with perl a bunch today a managed to take advantage of how Perl and C use different comment characters. Here are two methods to write a program that runs as either C or Perl: 
#include <stdio.h> // prints 99 Bottles of beer on the wall. Works as 
+either a C or a Perl program.
#define PERL C /*
"*/
int main(){//"; {
    int $bottles;
    $bottles=99;
    while($bottles){
        printf("%d bottle%s of beer on the wall, %d bottle%s of beer.\
+n", $bottles, $bottles==1?"":"s", $bottles, $bottles==1?"":"s");
        printf("Take one down and pass it around, ");
        if($bottles==1){
            printf("no more bottles of beer on the wall.\n\n");
        } 
        else{
            printf("%d bottle%s of beer on the wall.\n\n", $bottles-1,
+ $bottles==2?"":"s");
        }
        $bottles--;
    }
    printf("No more bottles of beer on the wall, no more bottles of be
+er.\n");
    printf("Go to the store and buy some more, 99 bottles of beer of t
+he wall.");
}

[download]
and using a bit different method: 
#include <stdio.h>
#define sub void
#define $x char *$t
#define chomp gets
sub main(){
    $x;
    printf("Please enter your name: ");
    #if 0
    $t = <>;
    #endif
    chomp($t);
    printf("Hello, %s!", $t);
}
#if 0
main();
#endif

[download]

In reply to Dual language by smeezekitty

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.