Reading Specific Data From A Text File?

[anthonyc]

Hello All,

 

Please excuse my lack of knowledge in advance, I'm a beginner but pick things up relatively quickly, and tend to do things by trial and error.

 

I would appreciate any help that anyone could offer with the following:

 

I would like to retrieve two pieces of data from a "text file" and use them to calculate a result from a function I have in javascript. An example of the javascript code is:

 

<script type="text/javascript">

function calculate() {

var drybulb = document.calc_form.drybulb.value;

var relhum = document.calc_form.relhum.value;

var answer = '';

if (drybulb !== '' && relhum !== '') {

answer = (0.567*drybulb*1) + (0.393 * (relhum*1/100 * 6.105 * Math.exp(17.27 * drybulb / (237.7 + drybulb*1)))) + 3.94;

}

document.calc_form.answer.value = answer;

return false;

}

</script>

 

Currently this is evaluated with entry from a simple html form, but I would like to have this performed "automatically".

 

 

The "text file" that I would like to access is here, not on my server:

 

http://www.bom.gov.au/fwo/IDV60901/IDV60901.94870.axf

 

I would like to extract the "air_temp" and "rel_hum" values under the [data] section for use in my function. I just need the "most recent" values (i.e. first), not all those contained in the file. This is a single record from that section (sorry for the mess this no doubt makes):

 

[data]

sort_order,wmo,name[80],history_product[80],local_date_time[80],local_date_time_full[80],aifstime_utc[80],air_temp,apparent_t,cloud[80],cloud_base_m,cloud_oktas,cloud_type[80],cloud_type_id,delta_t,dewpt,gust_kmh,gust_kt,lat,lon,press,press_msl,press_qnh,press_tend[80],rain_trace[80],rel_hum,sea_state[80],swell_dir_worded[80],swell_height,swell_period,vis_km[80],weather[80],wind_dir[80],wind_spd_kmh,wind_spd_kt

0,94870,"Moorabbin Airport","IDV60901","27/10:00pm","20120227220000","20120227110000",18.8,19.3,"Partly cloudy",510,3,"-",-9999,0.8,17.5,13,7,-38.0,145.1,1013.5,-9999.0,1013.5,"-","11.4",92,"-","-",-9999.0,-9999,"10","-","S",11,6

 

 

 

Would it be possible to obtain these values using PHP?, and if so any advice on how this could be done (noting my minimal knowledge) would be greatly appreciated.

 

Cheers.

 

[dragon_sa]

Here you go use the variables $airTemp and $relHum as you like in your javascript as you like

 

<?php
$data=file('http://www.bom.gov.au/fwo/IDV60901/IDV60901.94870.axf');
foreach ($data as $line) {
$info = explode(",", $line);
if ($info[0] == '0') { 
	$airTemp = $info[7];
	$relHum = $info[25];
	break;
}
}
echo "Air Temperature is: $airTemp<br/>";
echo "Relative Humidity is: $relHum %";
?>

[anthonyc]

Thank you for your help, can't believe how fast that was and how simple you made it look.

I have this working now, but might be back for more......

 

Cheers.

[Naps]

Thanks, helpful to me too.