Function clientSetNameOrReply

app/redis-6.2.6/src/networking.c:2396–2423

This function implements CLIENT SETNAME, including replying to the * user with an error if the charset is wrong (in that case C_ERR is * returned). If the function succeeeded C_OK is returned, and it's up * to the caller to send a reply if needed. * * Setting an empty string as name has the effect of unsetting the * currently set name: the client will remain unnamed. * * This function is a

 *
 * This function is also used to implement the HELLO SETNAME option. */
int clientSetNameOrReply(client *c, robj *name) {
    int len = sdslen(name->ptr);
    char *p = name->ptr;

    /* Setting the client name to an empty string actually removes
     * the current name. */
    if (len == 0) {
        if (c->name) decrRefCount(c->name);
        c->name = NULL;
        return C_OK;
    }

    /* Otherwise check if the charset is ok. We need to do this otherwise
     * CLIENT LIST format will break. You should always be able to
     * split by space to get the different fields. */
    for (int j = 0; j < len; j++) {
        if (p[j] < '!' || p[j] > '~') { /* ASCII is assumed. */
            addReplyError(c,
                "Client names cannot contain spaces, "
                "newlines or special characters.");
            return C_ERR;
        }
    }
    if (c->name) decrRefCount(c->name);
    c->name = name;
    incrRefCount(name);
    return C_OK;
}

/* Reset the client state to resemble a newly connected client.
 */