&reftitle.constants; &extension.constants.core;

# openlog Options

Constant | Description
`LOG_CONS` | if there is an error while sending data to the system logger, write directly to the system console
`LOG_NDELAY` | open the connection to the logger immediately
`LOG_ODELAY` | (default) delay opening the connection until the first message is logged
`LOG_NOWAIT` |
`LOG_PERROR` | print log message also to standard error
`LOG_PID` | include PID with each message

## `openlog` Facilities

Constant | Description
`LOG_AUTH` | security/authorization messages (use `LOG_AUTHPRIV` instead in systems where that constant is defined)
`LOG_AUTHPRIV` | security/authorization messages (private)
`LOG_CRON` | clock daemon (cron and at)
`LOG_DAEMON` | other system daemons
`LOG_KERN` | kernel messages
`LOG_LOCAL0 ... LOG_LOCAL7` | reserved for local use, these are not available in Windows
`LOG_LPR` | line printer subsystem
`LOG_MAIL` | mail subsystem
`LOG_NEWS` | USENET news subsystem
`LOG_SYSLOG` | messages generated internally by syslogd
`LOG_USER` | generic user-level messages
`LOG_UUCP` | UUCP subsystem

## `syslog` Priorities (in descending order)

Constant | Description
`LOG_EMERG` | system is unusable
`LOG_ALERT` | action must be taken immediately
`LOG_CRIT` | critical conditions
`LOG_ERR` | error conditions
`LOG_WARNING` | warning conditions
`LOG_NOTICE` | normal, but significant, condition
`LOG_INFO` | informational message
`LOG_DEBUG` | debug-level message

## `dns_get_record` Options

Constant | Description
`DNS_A` | IPv4 Address Resource
`DNS_CAA` | Certification Authority Authorization Resource (available as of PHP 7.0.16 and 7.1.2)
`DNS_MX` | Mail Exchanger Resource
`DNS_CNAME` | Alias (Canonical Name) Resource
`DNS_NS` | Authoritative Name Server Resource
`DNS_PTR` | Pointer Resource
`DNS_HINFO` | Host Info Resource (See IANA's `Operating System Names` for the meaning of these values)
`DNS_SOA` | Start of Authority Resource
`DNS_TXT` | Text Resource
`DNS_ANY` | Any Resource Record. On most systems this returns all resource records, however it should not be counted upon for critical uses. Try `DNS_ALL` instead.
`DNS_AAAA` | IPv6 Address Resource
`DNS_ALL` | Iteratively query the name server for each available record type.