The above line of code can also be written like this:

            void exit(int status);
            int printf(const char *, ...);
            
            int _start(){
                exit(!print("%s",(char []){'C',' ','i','s',' ','c','o','o','l'));
            }
          

Or even simpler, like this:

            #include 
            #include 

            int maini(){
                printf("%s","C is cool");
                exit(0);
            }
          

(This technically is not the same program, but it outputs the same thing and uses similar logic)

Ugly Code Breakdown:

• "void exit(int status);" is there to prototype the exit function, but you can include stdlib.h instead
• "int printf(const char *, ...);" is there to prototype the printf function, but you can include stdio.h instead
• "int _start()" is what the program enters before main. It is normally used to set up memory allocations and initialize some standard libraries, but for our case, we can override it to preempt the main function call and make our code less readable! It is also why we need the "-nostartfiles" tag in the compile command, so that gcc does not try to use the default "_start()" function.
• Any "<%" or "%>" can be read as "{" or "}". These character patterns are called "digraphs", and they are legacy notation for C that was implemented in case a computer did not have the curly brace keys (or some other keys). There are also trigraphs for the same purpose! "??<" and ">??" also represent curly braces!
• "exit(...)" is what exits us from the "_start()" function. We might want to try to make our code shorter by making this a return statement, but in this case we cannot. "_start()" normally calls "main()", so if we return with "main()", we are going back to the memory address where "main()" was called, in "_start()". Since there is not an outer function calling "_start()", we must use an exit command because there is no memory location to return to.
• The "!" is simply there to make sure "exit()" says that the program succeeded. "printf()" returns the number of characters that it printed, and "exit()" thinks something failed if you input anything other than a 0 or "false". Therefore, putting the "!" operator in front of a non-zero value, gives a "false", making "exit()" report that everything succeeded.
• The (char []) casts the array that follows it as an array of characters, allowing it to be printed as a string, since that is all a string is in C.
• Finally, the digits in the array! If you have ever seen jokes about how "010 == '8'" in Javascript, this is actually where that came from! "010 == 8" would return true in C! We are familiar with base 10 numbers being represented as normal numbers in coding, and some languages implement "0x" as the prefix for base 16 numbers (like hexadecimal 0x20 is 32 in base 10). Similarly, C has a prefix for base 8, or octal, but it just happens to be "0", without the "x"! This means that each of those numbers in that array is an octal number that is being cast to characters, which in turn are their ASCII table values!

Now, this specific program very obviously does not follow best coding practices, breaks convention, and should not be how we normally code. However, it is really fun sometimes to do things with code just because you can! And learning the ins and outs through silly coding usually helps you learn a thing or two about your computer.

I hope you enjoyed my obnoxious code breakdown! Happy coding!