How PHP determines if it is a valid IP address

When most people see this log, the first impression must be to say how to judge through regular expressions. This article mainly introduces the PHP judgment IP as a valid IP address method, the need for friends can refer to, hope to help everyone.

Not also, after php5.2.0, there is a special function to do this judgment.

Determine if it is a legitimate IP

if (Filter_var ($ip, filter_validate_ip)) {//it ' s valid}else {//It's not valid}

Determine if the IPV4 IP address is valid

if (Filter_var ($ip, Filter_validate_ip, Filter_flag_ipv4)) {//it ' s valid}else {//It's not valid}

Determine if it is a valid public IPv4 address, 192.168.1.1 This type of private IP address will be excluded

if (Filter_var ($ip, filter_validate_ip, Filter_flag_ipv4 | Filter_flag_no_priv_range)) {//it ' s valid}else {//It's not valid}

Determine if the IPV6 address is valid

if (Filter_var ($ip, Filter_validate_ip, Filter_flag_no_res_range)) {//it ' s valid}else {//It's not valid}

Determines whether the public IPv4 IP or is a legitimate public IPv6 IP address

if (Filter_var ($ip, filter_validate_ip, Filter_flag_no_priv_range | Filter_flag_no_res_range)) {//it ' s valid}else {//It's not valid}