Function ttlGenericCommand

app/redis-6.2.6/src/expire.c:557–577

Implements TTL and PTTL */

/* Implements TTL and PTTL */
void ttlGenericCommand(client *c, int output_ms) {
    long long expire, ttl = -1;

    /* If the key does not exist at all, return -2 */
    if (lookupKeyReadWithFlags(c->db,c->argv[1],LOOKUP_NOTOUCH) == NULL) {
        addReplyLongLong(c,-2);
        return;
    }
    /* The key exists. Return -1 if it has no expire, or the actual
     * TTL value otherwise. */
    expire = getExpire(c->db,c->argv[1]);
    if (expire != -1) {
        ttl = expire-mstime();
        if (ttl < 0) ttl = 0;
    }
    if (ttl == -1) {
        addReplyLongLong(c,-1);
    } else {
        addReplyLongLong(c,output_ms ? ttl : ((ttl+500)/1000));
    }
}

/* TTL key */
void ttlCommand(client *c) {