How to know if is a redis key exits about lua-resty-redis

[bjoe2k4]

Quote from the lua-resty-redis documentation:

A nil bulk reply results in a ngx.null return value.

Therefore you need to check against ngx.null:

if val == ngx.null then
    ngx.say("the value is not exists.")
else 
    ngx.say("val: "..val)
end

[pbby]

Thank you for reply, I'm sorry have not focus on it.
I test it and it worked.

[bjoe2k4]

can you close the issue?

[Habbie]

(I understand I'm commenting on a closed issue which may mean nobody will remember to respond to this, will try harder later).

README.markdown has this snippet:

                local res, err = red:get("dog")
                if not res then
                    ngx.say("failed to get dog: ", err)
                    return
                end

and that's how I ran into this 'issue' as well. Is the README indeed wrong? Want me to submit a patch for it?

[agentzh]

No, the doc is correct and precise. Look more carefully.

[agentzh]

nil is returned for fatal errors like network problems, which is apparently a different thing.