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HASH CONVENIENCES(3)  DragonFly Library Functions Manual  HASH CONVENIENCES(3)


NAME

     hash_compare_int, hash_compare_string, hash_hash_int, hash_hash_string,
     hash_copy_int, hash_copy_string - libhash convenience functions


LIBRARY

     Hash Library (libhash, -lhash)


SYNOPSIS

     #include <sys/types.h>
     #include <hash.h>

     int
     hash_compare_int(void *key1, void *key2);

     int
     hash_compare_string(void *key1, void *key2);

     u_int32_t
     hash_hash_int(void *key, u_int32_t number_of_buckets);

     u_int32_t
     hash_hash_string(void *key, u_int32_t number_of_buckets);

     int
     hash_copy_int(void **destination, void *source);

     int
     hash_copy_string(void **destination, void *source);


DESCRIPTION

     These functions are provided by libhash as a convenience for users. They
     are all designed to be passed to hash_initialise() as one of the
     parameters.

     The functions hash_compare_int() and hash_compare_string() are designed
     to be passed to hash_initialise() as the compare_keys argument.
     hash_compare_int() works with keys that are integers and
     hash_compare_string() works with keys that are nul terminated char arrays
     (strings).  hash_compare_string() performs a case sensistive
     lexicographical comparison.

     The functions hash_hash_int() and hash_hash_string() are designed to be
     passed to hash_initialise() as the hash_function argument.
     hash_hash_int() works with keys that are integers and hash_hash_string()
     works with keys that are nul terminated char arrays (strings).

     The functions hash_copy_int() and hash_copy_string() are designed to be
     passed to hash_initialise() as the duplicate_key argument.
     hash_copy_int() works with keys that are integers and hash_copy_string()
     works with keys that are nul terminated char arrays (strings).


RETURN VALUES

     The hash_compare_int(), and hash_compare_string() functions return a
     value less than 0 if key1 is less than key2, a value equal to 0 if key1
     is equal to key2 and a value greater than 0 if key1 is greater than key2.

     hash_hash_int() and hash_hash_string() return a number between 0 and
     number_of_buckets - 1.

     hash_copy_int() and hash_copy_string() return 0 on failure and set the
     global variable errno to indicate the error.


EXAMPLES

     See the tests directory included in the distribution.


ERRORS

     [ENOMEM]
             A call to malloc failed.


SEE ALSO

     libhash(3)


HISTORY

     The libhash library was written in January 2002 for emmao (a program to
     kill off rogue processes under Solaris).  libhash was written under
     FreeBSD 4.4.


AUTHORS

     Andrew Stevenson <andrew@ugh.net.au>


BUGS

     hash_hash_string() is a very simple algorithm and good be improved
     greatly.

     Please report others to <andrew@ugh.net.au>.

UgH!                           January 14, 2002                           UgH!

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