The getservbyname() function is an inbuilt function in PHP which returns the port number for given protocol and Internet service.
Syntax:
int getservbyname( string $service, string $protocol )
Parameters: This function accepts two parameters as mentioned above and described below:
- $protocol: It is required parameter. It specifies protocol name, like tcp, udp etc in string format.
- $service: It is required parameter. It specifies the Internet service name, like http int string format.
Return Value: This function returns the port number on success or False if service or protocol not found.
Note: This function is available for PHP 4.0.0 and newer version.
Below programs illustrate the getservbyname() function in PHP:
Program 1:
<?php   // Use getservbyname() function to get // port number associated with an // Internet service and protocol $portnum = getservbyname("http", "tcp");   // Display the result echo $portnum;   ?> |
Output:
80
Program 2: This program checks multiple services.
<?php    // Create an array of services $services = array("ftp", "ssh",             "telnet", "http", "https");   // Loop run for each services foreach( $services as $index) {           // Use getservbyname() function to get     // the port number associated with an     // Internet service and protocol     echo getservbyname($index, "tcp")             . ": " . $index . "<br>"; }   ?> |
Output:
21: ftp 22: ssh 23: telnet 80: http 443: https
Reference: https://www.php.net/manual/en/function.getservbyname.php
