Sqids (pronounced "squids") is an open-source library that lets you generate short unique identifiers from numbers. These IDs are URL-safe, can encode several numbers, and do not contain common profanity words. Read more .
This is what they look like:
C code is located at https://github.com/sqids/sqids-c
To encode & decode:
sqids_t *sqids = sqids_new(SQIDS_DEFAULT_ALPHABET, 0, sqids_bl_list_all(NULL));
unsigned long long nums[] = {1, 2, 3};
char *hash = sqids_encode(sqids, 3, nums); // => "86Rf07"
sqids_decode(sqids, hash, nums, 3); // => 3Randomize IDs by providing a custom alphabet:
sqids_t *sqids = sqids_new("FxnXM1kBN6cuhsAvjW3Co7l2RePyY8DwaU04Tzt9fHQrqSVKdpimLGIJOgb5ZE", 0, sqids_bl_list_all(NULL));
unsigned long long nums[] = {1, 2, 3};
char *hash = sqids_encode(sqids, 3, nums); // => "B4aajs"
sqids_decode(sqids, hash, nums, 3); // => 3Enforce a minimum length for IDs:
sqids_t *sqids = sqids_new(SQIDS_DEFAULT_ALPHABET, 10, sqids_bl_list_all(NULL));
unsigned long long nums[] = {1, 2, 3};
char *hash = sqids_encode(sqids, 3, nums); // => "86Rf07xd4z"
sqids_decode(sqids, hash, nums, 3); // => 3Read more at https://github.com/sqids/sqids-c
If you're looking for the original Hashids C, you can find it here .
The main use of Sqids is purely visual. If you'd like to use IDs instead of numbers in your webapp, Sqids could be a good choice: