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encap_hash_new(3)               C Library Calls              encap_hash_new(3)


NAME

       encap_hash_new, encap_hash_free, encap_hash_next, encap_hash_prev,
       encap_hash_getkey, encap_hash_search, encap_hash_add, encap_hash_del -
       hash table routines


SYNOPSIS

       #include <encap.h>

       encap_hash_t *encap_hash_new(int num, int (*hashfunc)());
       void encap_hash_free(encap_hash_t *h, void (*freefunc)());
       int encap_hash_next(encap_hash_t *h, encap_hashptr_t *hp);
       int encap_hash_prev(encap_hash_t *h, encap_hashptr_t *hp);
       int encap_hash_search(encap_hash_t *h, encap_hashptr_t *hp, void *data,
       int (*matchfunc)());
       int encap_hash_getkey(encap_hash_t *h, encap_hashptr_t *hp, void *data,
       int (*matchfunc)());
       int encap_hash_add(encap_hash_t *h, void *data);
       int encap_hash_del(encap_hash_t *h, encap_hashptr_t *hp);


DESCRIPTION

       The encap_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 encap_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 encap_hash_next() and encap_hash_prev() functions are used to
       iterate through the hash.  The encap_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 encap_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 encap_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 encap_hash_add() function adds data into hash h.

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


RETURN VALUE

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

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

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

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

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


SEE ALSO

       encap_list_new(3)

University of Illinois             Jan 2000                  encap_hash_new(3)

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