PHP | getservbyname() Function

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