PHP Network Functions Cheat Sheet

PHP Network functions can be used to open network connections, send and receive data over the network, and perform other tasks such as checking DNS records, resolving hostnames and IP addresses, and sending HTTP headers.

Common examples of PHP network functions include fsockopen() (which opens a network connection), dns_get_record() (which retrieves DNS resource records for a given domain), and gethostbyname() (which resolves a hostname to an IP address).

Here is a complete list and brief description on each:

Function	Description	Deprecated
`checkdnsrr()`	Check DNS records for a given domain	No
`closelog()`	Close connection to system logger	No
`dns_check_record()`	Check DNS records for a given domain	No
`dns_get_mx()`	Get MX records for a given domain	No
`dns_get_record()`	Get DNS resource records for a domain	No
`fsockopen()`	Open a network connection	No
`gethostbyaddr()`	Get the hostname for a given IP address	No
`gethostbyname()`	Get the IP address for a given hostname	No
`gethostbynamel()`	Get the IP addresses for a given hostname	No
`getmxrr()`	Get MX records for a given domain	No
`getprotobyname()`	Get protocol number for a protocol name	No
`getprotobynumber()`	Get protocol name for a protocol number	No
`getservbyname()`	Get port number for a service name	No
`getservbyport()`	Get service name for a port number	No
`header()`	Send a raw HTTP header	No
`inet_ntop()`	Convert a packed IPv4/IPv6 address to a human-readable string	No
`inet_pton()`	Convert a human-readable IP address to a packed string	No
`long2ip()`	Convert an long integer to an IP address	No
`openlog()`	Open connection to system logger	No
`pfsockopen()`	Open a persistent network connection	No
`setcookie()`	Send a cookie	No
`setrawcookie()`	Send a raw HTTP cookie	No
`socket_get_status()`	Get the status of a socket	No
`syslog()`	Send a message to the system logger	No
`define_syslog_variables()`	Initialize syslog variables	Yes
`dl()`	Load a PHP extension at runtime	Yes
`php_uname()`	Return information about the system PHP is running on	Yes
`PHP_OS`	A predefined constant containing the operating system PHP is running on	Yes
`PHP_OS_FAMILY`	A predefined constant containing the operating system family PHP is running on	Yes
`PHP_SAPI`	A predefined constant containing the type of interface PHP is using to communicate with the web server	Yes

It is worth noting that many PHP network functions are based on the underlying C library functions for network programming, such as socket(), connect(), and send(). As such, they may be more low-level and require a deeper understanding of network programming concepts to use effectively.