RRD 函数
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rrd_info

(PECL rrd >= 0.9.0)

rrd_info — Gets information about rrd file

说明

array rrd_info ( string $filename )

Returns information about particular RRD database file.

参数

file

RRD database file name.

返回值

Array with information about requsted RRD file, FALSE when error occurs.

RRD 函数
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PHP手册
PHP手册 - N: Gets information about rrd file

用户评论:

cfsalguero at gmail dot com (22-Feb-2012 11:45)

rrd_info will return an array where the keys are all strings that represents another arrays like in this example:
Array
(
    [filename] => /var/www/cacti/rra/localhost_mem_swap_26.rrd
    [rrd_version] => 0003
    [step] => 300
    [last_update] => 1329924661
    [header_size] => 1892
    [ds[mem_swap].index] => 0
    [ds[mem_swap].type] => GAUGE
    [ds[mem_swap].minimal_heartbeat] => 600
    [ds[mem_swap].min] => 0
    [ds[mem_swap].max] => NAN
    [ds[mem_swap].last_ds] => 2084332
    [ds[mem_swap].value] => 127144252
    [ds[mem_swap].unknown_sec] => 0
    [rra[0].cf] => AVERAGE
    [rra[0].rows] => 600
    [rra[0].cur_row] => 266
    [rra[0].pdp_per_row] => 1
    [rra[0].xff] => 0.5
    [rra[0].cdp_prep[0].value] => NAN
    [rra[0].cdp_prep[0].unknown_datapoints] => 0
)
I made a function that converts that into a real array structure:
<?php

function rrdinfo($filename) {

    /*
       Inner functions to make them inaccesible from the outside of the main function
    */
    function add($key, $value, &$main_table) {
        if (is_array($value)) {
            foreach ($value as $k => $v) {
                add($k, $v, $main_table[$key]);
            }
        } else {
            $main_table[$key] = $value;
        }
    }

    function toobj($key, $value) {
        $matches = array();
        if (preg_match('/^\[(.*)\]$/', $key, $matches)) {
            $key = $matches[1];
        }
        if (preg_match('/(.*?)\[(.*?)\]\.(.*)/', $key, $matches)) {
            $matches2 = array();
            if (preg_match('/(.*?)\[(.*?)\]\.(.*)/', $matches[3], $matches2)) {
                $ret_key = $matches[1];                                
                list($k, $v) = toobj($matches[3], $value);
                $ret_val = array($matches[2] => array($k => $v));
            } else {
                $ret_key = $matches[1];                                
                $ret_val = array($matches[2] => array ($matches[3] => $value));
            }
        } else {
            $ret_key = $key;
            $ret_val = $value;
        }
        return array($ret_key, $ret_val);
    }

    /*
       Main program code
    */
    $main_table = array();
    $info = rrd_info($filename);
    foreach ($info as $ds_key => $ds_value) {
        list ($key, $value) = toobj($ds_key, $ds_value);
         add($key, $value, $main_table);
    }
    return $main_table;
}

And this is the way to use it:

$filename = "/path/to/your/rrd/file/localhost_mem_swap_26.rrd";
$info = rrdinfo($filename);