libtar_hash_new(3)              C Library Calls             libtar_hash_new(3)

       libtar_hash_new, libtar_hash_free, libtar_hash_next, libtar_hash_prev,
       libtar_hash_getkey, libtar_hash_search, libtar_hash_add,
       libtar_hash_del - hash table routines

       #include <libtar.h>

       libtar_hash_t *libtar_hash_new(int num, int (*hashfunc)());
       void libtar_hash_free(libtar_hash_t *h, void (*freefunc)());
       int libtar_hash_next(libtar_hash_t *h, libtar_hashptr_t *hp);
       int libtar_hash_prev(libtar_hash_t *h, libtar_hashptr_t *hp);
       int libtar_hash_search(libtar_hash_t *h, libtar_hashptr_t *hp, void
       *data, int (*matchfunc)());
       int libtar_hash_getkey(libtar_hash_t *h, libtar_hashptr_t *hp, void
       *data, int (*matchfunc)());
       int libtar_hash_add(libtar_hash_t *h, void *data);
       int libtar_hash_del(libtar_hash_t *h, libtar_hashptr_t *hp);

       The libtar_hash_new() function creates a new hash with num buckets and
       using hash function pointed to by hashfunc.  If hashfunc is NULL, a
       default hash function designed for 7-bit ASCII strings is used.

       The libtar_hash_free() function deallocates all memory associated with
       the hash structure h.  If freefunc is not NULL, it is called to free
       memory associated with each node in the hash.

       The libtar_hash_next() and libtar_hash_prev() functions are used to
       iterate through the hash.  The libtar_hashptr_t structure has two
       fields: bucket, which indicates the current bucket in the hash, and
       node, which is a pointer to the current node in the current bucket.  To
       start at the beginning or end of the hash, the caller should initialize
       hp.bucket to -1 and hp.node to NULL.

       The libtar_hash_search() function searches iteratively through the hash
       h until it finds a node whose contents match data using the matching
       function matchfunc.  Searching begins at the location pointed to by hp.

       The libtar_hash_getkey() function uses the hash function associated
       with h to determine which bucket data should be in, and searches only
       that bucket for a matching node using matchfunc.  Searching begins at
       the location pointed to by hp.

       The libtar_hash_add() function adds data into hash h.

       The libtar_hash_del() function removes the node referenced by hp.

       The libtar_hash_new() function returns a pointer to the new hash
       structure, or NULL on error.

       The libtar_hash_next() and libtar_hash_prev() functions return 1 when
       valid data is returned, and 0 at the end of the hash.

       The libtar_hash_getkey() and libtar_hash_search() functions return 1
       when a match is found, or 0 otherwise.

       The libtar_hash_add() function returns 0 on success, or -1 on error
       (and sets errno).

       The libtar_hash_del() function returns 0 on success, or -1 on error
       (and sets errno).


University of Illinois             Jan 2000                 libtar_hash_new(3)