上一节《Zookeeper C API 指南三(回调函数)》重点讲了 Zookeeper C API 中各种回调函数的原型，本节将切入正题，，正式讲解 Zookeeper C API。相信大家读完本文后应该对 Zookeeper C API 的使用有一个比较清晰的认识。
Zookeeper C API 概览Zookeeper C API 很规范，接口很容易记忆，大部分接口均以 zoo_ 开头，只有少量接口以 zookeeper_ 开头，所有的 API 汇总如下：
void zoo_create_op_init(zoo_op_t * op, const char *path, const char *value, int valuelen, const struct ACL_vector *acl, int flags, char *path_buffer, int path_buffer_len); void zoo_delete_op_init(zoo_op_t * op, const char *path, int version); void zoo_set_op_init(zoo_op_t * op, const char *path, const char *buffer, int buflen, int version, struct Stat *stat); void zoo_check_op_init(zoo_op_t * op, const char *path, int version); ZOOAPI zhandle_t *zookeeper_init(const char *host, watcher_fn fn, int recv_timeout, const clientid_t * clientid, void *context, int flags); ZOOAPI int zookeeper_close(zhandle_t * zh); ZOOAPI const clientid_t *zoo_client_id(zhandle_t * zh); ZOOAPI int zoo_recv_timeout(zhandle_t * zh); ZOOAPI const void *zoo_get_context(zhandle_t * zh); ZOOAPI void zoo_set_context(zhandle_t * zh, void *context); ZOOAPI watcher_fn zoo_set_watcher(zhandle_t * zh, watcher_fn newFn); ZOOAPI struct sockaddr *zookeeper_get_connected_host(zhandle_t * zh, struct sockaddr *addr, socklen_t * addr_len); ZOOAPI int zookeeper_interest(zhandle_t * zh, int *fd, int *interest, struct timeval *tv); ZOOAPI int zookeeper_process(zhandle_t * zh, int events); ZOOAPI int zoo_state(zhandle_t * zh); ZOOAPI int zoo_acreate(zhandle_t * zh, const char *path, const char *value, int valuelen, const struct ACL_vector *acl, int flags, string_completion_t completion, const void *data); ZOOAPI int zoo_adelete(zhandle_t * zh, const char *path, int version, void_completion_t completion, const void *data); ZOOAPI int zoo_aexists(zhandle_t * zh, const char *path, int watch, stat_completion_t completion, const void *data); ZOOAPI int zoo_awexists(zhandle_t * zh, const char *path, watcher_fn watcher, void *watcherCtx, stat_completion_t completion, const void *data); ZOOAPI int zoo_aget(zhandle_t * zh, const char *path, int watch, data_completion_t completion, const void *data); ZOOAPI int zoo_awget(zhandle_t * zh, const char *path, watcher_fn watcher, void *watcherCtx, data_completion_t completion, const void *data); ZOOAPI int zoo_aset(zhandle_t * zh, const char *path, const char *buffer, int buflen, int version, stat_completion_t completion, const void *data); ZOOAPI int zoo_aget_children(zhandle_t * zh, const char *path, int watch, strings_completion_t completion, const void *data); ZOOAPI int zoo_awget_children(zhandle_t * zh, const char *path, watcher_fn watcher, void *watcherCtx, strings_completion_t completion, const void *data); ZOOAPI int zoo_aget_children2(zhandle_t * zh, const char *path, int watch, strings_stat_completion_t completion, const void *data); ZOOAPI int zoo_awget_children2(zhandle_t * zh, const char *path, watcher_fn watcher, void *watcherCtx, strings_stat_completion_t completion, const void *data); ZOOAPI int zoo_async(zhandle_t * zh, const char *path, string_completion_t completion, const void *data); ZOOAPI int zoo_aget_acl(zhandle_t * zh, const char *path, acl_completion_t completion, const void *data); ZOOAPI int zoo_aset_acl(zhandle_t * zh, const char *path, int version, struct ACL_vector *acl, void_completion_t, const void *data); ZOOAPI int zoo_amulti(zhandle_t * zh, int count, const zoo_op_t * ops, zoo_op_result_t * results, void_completion_t, const void *data); ZOOAPI const char *zerror(int c); ZOOAPI int zoo_add_auth(zhandle_t * zh, const char *scheme, const char *cert, int certLen, void_completion_t completion, const void *data); ZOOAPI int is_unrecoverable(zhandle_t * zh); ZOOAPI void zoo_set_debug_level(ZooLogLevel logLevel); ZOOAPI void zoo_set_log_stream(FILE * logStream); ZOOAPI void zoo_deterministic_conn_order(int yesOrNo); ZOOAPI int zoo_create(zhandle_t * zh, const char *path, const char *value, int valuelen, const struct ACL_vector *acl, int flags, char *path_buffer, int path_buffer_len); ZOOAPI int zoo_delete(zhandle_t * zh, const char *path, int version); ZOOAPI int zoo_exists(zhandle_t * zh, const char *path, int watch, struct Stat *stat); ZOOAPI int zoo_wexists(zhandle_t * zh, const char *path, watcher_fn watcher, void *watcherCtx, struct Stat *stat); ZOOAPI int zoo_get(zhandle_t * zh, const char *path, int watch, char *buffer, int *buffer_len, struct Stat *stat); ZOOAPI int zoo_wget(zhandle_t * zh, const char *path, watcher_fn watcher, void *watcherCtx, char *buffer, int *buffer_len, struct Stat *stat); ZOOAPI int zoo_set(zhandle_t * zh, const char *path, const char *buffer, int buflen, int version); ZOOAPI int zoo_set2(zhandle_t * zh, const char *path, const char *buffer, int buflen, int version, struct Stat *stat); ZOOAPI int zoo_get_children(zhandle_t * zh, const char *path, int watch, struct String_vector *strings); ZOOAPI int zoo_wget_children(zhandle_t * zh, const char *path, watcher_fn watcher, void *watcherCtx, struct String_vector *strings); ZOOAPI int zoo_get_children2(zhandle_t * zh, const char *path, int watch, struct String_vector *strings, struct Stat *stat); ZOOAPI int zoo_wget_children2(zhandle_t * zh, const char *path, watcher_fn watcher, void *watcherCtx, struct String_vector *strings, struct Stat *stat); ZOOAPI int zoo_get_acl(zhandle_t * zh, const char *path, struct ACL_vector *acl, struct Stat *stat); ZOOAPI int zoo_set_acl(zhandle_t * zh, const char *path, int version, const struct ACL_vector *acl); ZOOAPI int zoo_multi(zhandle_t * zh, int count, const zoo_op_t * ops, zoo_op_result_t * results);