PHP - RRD rrd_version() Function

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The PHP RRD rrd_version() function is used to know the information about underlying rrdtool library. This function does not accept any parameter and returns string with rrdtool version number.

Syntax

Below is the syntax of the PHP RRD rrd_version() function −

string rrd_version ()

Parameters

The rrd_version() function does not accept any parameter.

Return Value

This function returns string with the rrdtool version number for example 1.2.3.

PHP Version

The rrd_version() function is available from version 1.0.0 of the PECL rrd extension onwards.

Example 1

First we will show you the basic example of the PHP RRD rrd_version() function to get the information about installed version of rrd.

<?php
   // echo the installed rrd version
   echo "The rrd version is - ".rrd_version();
?>

Output

The above code will result something like this −

The rrd version is - 2.0.3

Example 2

Now in the below code we will store the version number returned by the rrd_version() function in a variable for later use.

<?php
   // Store the rrd version in a variable
   $rrdVersion = rrd_version();
   echo "The RRD library version is: " . $rrdVersion;
?> 

Output

This will create the below output −

The RRD library version is: 2.0.3

Example 3

This example shows how to check if a version satisfies a requirement inside of a conditional expression with the help of rrd_version() version.

<?php
   // Check the version using if-else
   if (version_compare(rrd_version(), '2.0.3', '>=')) {
      echo "Your RRD version is sufficient.";
   } else {
      echo "RRD version is outdated.";
   }
?> 

Output

After running the above program, it generates the following output −

Your RRD version is sufficient.

Example 4

This example shows how to send the version of the RRD library returned by the rrd_version() to a file for documentation. So this scenario is useful when you want to store the version number in a log file which can be useful when you want to maintain the records or debugging.

<?php
   // Store the rrd version in a variable
   $rrdVersion = rrd_version();
   $logFile = 'rrd_version_log.txt';
   
   file_put_contents($logFile, "RRD Library Version: " . $rrdVersion . "\n", FILE_APPEND);
   
   echo "RRD version logged to file.";
?> 

Output

When the above program is executed, it will produce the below output −

RRD version logged to file.

Content of the rrd_version_log.txt file −

RRD Library Version: 2.0.0