make all
./korn
The Judges believe that this is the best one line entry ever received. Compile on a UNIX system, or at least one using a C implementation that fakes it. Very few people are able to determine what this program does by visual inspection. I suggest that you stop reading this section right now and see if you are one of the few people who can.
Several points are important to understand this program:
What is the symbol unix
and what is its value in the program? Clearly
unix
is not a function, and since unix
is not declared to be a data type
(such as int
, char
, struct foo
, enum
, …) what must unix
be?
What is the value of the symbol "have"
? (hint: the value is NOT 4
characters, or 'h'
, or a string) Consider the fact that:
char *x;
defines a pointer to a char
(i.e. an address), and that the =
assigns
things of compatible types. Since:
= "have"; x
is legal C, what type of value is "have"
?
[3] *(x+3) *(3+x) x
since addition is commutative. What can be said about this value?
3[x]
David Korn’s /bin/ksh provides us with a greatly improved version of the /bin/sh. The source for v7’s /bin/sh greatly inspired this contest.
No remarks were provided by the author.