LXVII. Network Functions
Runtime Configuration
The behaviour of these functions is affected by settings in php.ini.
For further details and definition of the PHP_INI_* constants see ini_set().
Here's a short explanation of the configuration directives.
- define_syslog_variables boolean
- Whether or not to define the various syslog variables (e.g. $LOG_PID, $LOG_CRON, etc.). Turning it off is a good idea performance-wise. At runtime, you can define these variables by calling define_syslog_variables(). 
Predefined Constants
The constants below are always available as part of the PHP core.
Table 2. 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 | 
Table 3. 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 | 
Table 4. 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 | 
Table 5. dns_get_record() Options
| Constant | Description | 
|---|---|
| DNS_A | IPv4 Address Resource | 
| 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 | Itteratively query the name server for each available record type. | 
- Table of Contents
- checkdnsrr -- Check DNS records corresponding to a given Internet host name or IP address
- closelog -- Close connection to system logger
- debugger_off -- Disable internal PHP debugger (PHP 3)
- debugger_on -- Enable internal PHP debugger (PHP 3)
- define_syslog_variables -- Initializes all syslog related constants
- dns_check_record -- Synonym for checkdnsrr()
- dns_get_mx -- Synonym for getmxrr()
- dns_get_record -- Fetch DNS Resource Records associated with a hostname
- fsockopen -- Open Internet or Unix domain socket connection
- gethostbyaddr -- Get the Internet host name corresponding to a given IP address
- gethostbyname -- Get the IP address corresponding to a given Internet host name
- gethostbynamel -- Get a list of IP addresses corresponding to a given Internet host name
- getmxrr -- Get MX records corresponding to a given Internet host name
- getprotobyname -- Get protocol number associated with protocol name
- getprotobynumber -- Get protocol name associated with protocol number
- getservbyname -- Get port number associated with an Internet service and protocol
- getservbyport -- Get Internet service which corresponds to port and protocol
- ip2long -- Converts a string containing an (IPv4) Internet Protocol dotted address into a proper address.
- long2ip -- Converts an (IPv4) Internet network address into a string in Internet standard dotted format
- openlog -- Open connection to system logger
- pfsockopen -- Open persistent Internet or Unix domain socket connection
- socket_get_status -- Alias of stream_get_meta_data().
- socket_set_blocking -- Alias for stream_set_blocking()
- socket_set_timeout -- Alias for stream_set_timeout()
- syslog -- Generate a system log message
