1、使用rrdtool建立rrd文件,对人民币对美元汇率每20秒进行一次抓取(setp = 20s)
rrdtool create USDCNY.rrd \ --start `date +%s` \ --step 20 \ DS:content:GAUGE:100:0:U \ RRA:AVERAGE:0:1:400
2、 通过Yahoo提供的汇率查询解决取得当前汇率,并存入rrd文件
#!/bin/bash PATH='/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin' rrdfile='/tmp/361way/USDCNY.rrd' while true do timestamp=`date +%s` rmbrate=`curl 'http://download.finance.yahoo.com/d/quotes.csv?s=USDCNY=X&f=sl1d1t1&e=.csv' 2>/dev/null | awk -F, '{print $2}'` rrdtool update $rrdfile ${timestamp}:${rmbrate} sleep 19 echo 'get now' done
3、使用php脚本展示人民币汇率rrd图
# cat rmb.php <?php header("Content-type:image/png"); $cmd=' /usr/bin/rrdtool graph - \ -h 120 -w 500 \ --start now-1h \ -v "RMB/USD" --title "RMB-USD Rate" \ DEF:rmbrate=/tmp/361way/USDCNY.rrd:content:AVERAGE \ LINE:rmbrate#00CF00FF:"RMB Rate" \ COMMENT:"\n" '; passthru($cmd); ?>
效果图如下:
参考页面:http://www.vandenbogaerdt.nl/rrdtool/after_the_fact.php