UT_HASH

参考
https://blog.csdn.net/Dusong_/article/details/128757067
http://cnblogs.com/aclove/articles/3803110.html
https://blog.csdn.net/changan277/article/details/140460532

UT_hash_handle hh

HASH_ADD_STR(head,strfield,add)
HASH_ADD_INT(head,intfield,add)
HASH_ADD_PTR(head,ptrfield,add)

HASH_FIND_STR(head,findstr,out)
HASH_FIND_INT(head,findint,out)
HASH_FIND_PTR(head,findptr,out)

遍历
HASH_ITER(hh, users, s, tmp)