Best One Liner

David Korn
AT&T Bell Labs
MH 3C-526B, AT&T Bell Labs
Murray Hill, NJ
07974
USA

Judges' comments:

The Judges believe that this is the best one line entry ever received. Compile on a UN*X system, or at least 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 in this program:

1) 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?

2) 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 character (i.e. an address), and that the ‘=’ assigns things is compatible types. Since:

    x = "have";

is legal C, what type of value is “have”?

3) Note that the following expressions yield the same value:

    x[3]    *(x+3)    *(3+x)

since addition is communitive. What can be said about the 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.

Copyright © 1987, Landon Curt Noll & Larry Bassel. All Rights Reserved. Permission for personal, educational or non-profit use is granted provided this this copyright and notice are included in its entirety and remains unaltered. All other uses must receive prior permission in writing from both Landon Curt Noll and Larry Bassel.