XCVII. Network Functions

Introduction

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Network Configuration Options

Name	Default	Changeable	Changelog
define_syslog_variables	"0"	PHP_INI_ALL

For further details and definitions of the PHP_INI_* constants, see the Appendix G.

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().

Resource Types

This extension has no resource types defined.

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	Iteratively 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
header -- Send a raw HTTP header
headers_list -- Returns a list of response headers sent (or ready to send)
headers_sent -- Checks if or where headers have been sent
inet_ntop -- Converts a packed internet address to a human readable representation
inet_pton -- Converts a human readable IP address to its packed in_addr representation
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
setcookie -- Send a cookie
setrawcookie -- Send a cookie without urlencoding the cookie value
socket_get_status -- Alias of stream_get_meta_data()
socket_set_blocking -- Alias of stream_set_blocking()
socket_set_timeout -- Alias of stream_set_timeout()
syslog -- Generate a system log message