Checks for the presence of a DNS record; this is an alias of checkdnsrr().
What Is dns_check_record() in PHP?
Checks for the presence of a DNS record; this is an alias of checkdnsrr().
Its syntax is:
dns_check_record(string $hostname, string $type = "MX"): boolParameters:
$hostname— Accepted as string; required argument.$type— Accepted as string; optional default "MX".
Return type: bool. DNS checks are network-dependent and presence of a record does not prove the host is safe or reachable.
Availability: Requires DNS access.
Example 1: Basic Usage
<?php
echo dns_check_record("example.com", "A") ? "Record present" : "No record found";
Result: Results and availability depend on the current PHP process, system permissions, cache, filesystem or installed locale. DNS checks are network-dependent and presence of a record does not prove the host is safe or reachable.
Example 2: A Different Input
<?php
echo dns_check_record("example.com", "MX") ? "Mail records exist" : "No mail records";
Result: Results and availability depend on the current PHP process, system permissions, cache, filesystem or installed locale. DNS checks are network-dependent and presence of a record does not prove the host is safe or reachable.
Practical Example: Applying It in a Program
<?php
foreach (["A", "AAAA", "MX"] as $recordType) { echo $recordType . ": " . (dns_check_record("example.com", $recordType) ? "yes" : "no") . PHP_EOL; }
Result: Results and availability depend on the current PHP process, system permissions, cache, filesystem or installed locale. DNS checks are network-dependent and presence of a record does not prove the host is safe or reachable.
Important Behavior and Edge Cases
- Key behavior: DNS checks are network-dependent and presence of a record does not prove the host is safe or reachable.
- Environment: Requires DNS access.
Comparison With Related Functions
| Function | Purpose |
|---|---|
dns_check_record() | Checks for the presence of a DNS record; this is an alias of checkdnsrr(). |
checkdnsrr() | dns_check_record() is an alias of checkdnsrr() and supports the same checks. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
| Ignoring this behavior: DNS checks are network-dependent and presence of a record does not prove the host is safe or reachable | DNS checks are network-dependent and presence of a record does not prove the host is safe or reachable. |
Key Takeaways
- Checks for the presence of a DNS record; this is an alias of checkdnsrr().
- DNS checks are network-dependent and presence of a record does not prove the host is safe or reachable.
- Requires DNS access.
Summary: DNS checks are network-dependent and presence of a record does not prove the host is safe or reachable.