哈希 - Sha512只使用字母和数字

Question

Im using hash to create a random string.

hash('sha512', uniqid());

Will the hash contain only letters and numbers or will other characters be used? If so, how can I limit it so only letters and numbers are used?

Answer 1

The third argument to hash() is $raw_output. The manual has this to say about this argument:

raw_output
When set to TRUE, outputs raw binary data. FALSE outputs lowercase hexits.

While it may be a bit cryptic, "lowercase hexits" means lowercase hexadecimal notation. Hexadecimal notation uses the characters 0-9 and A-F.

So yes, the output will contain only letters and numbers.