file retrieval....reg expression?

cave monkey · #1 23-Mar-2004, 10:23

I am trying to pull a weather report from a remote html page, and would like to know how to gather just the report ( not the whole page) for display on my own page. I have succesfully pulled the whole page into mine using the following code:

PHP Code:


@ $fp = fopen("http://url/index.html", "r");
if (!fp)
{
echo 'Data Temporarily Unanvailable!';
exit;
}
while (!feof($fp))
{
$weather = fgets($fp, 999);
echo $weather;
}

I have tried matching patterns with eregi() but without success, as the text of the weather report is different each day. However, the location of the text in the page is consistent, and it is clearly delineated with unique start and end points. How do I get my file pointer there, and not pull in the whole page? The url I'm retrieving from is here: http://pajk.arh.noaa.gov/index.php?fcst=AKZ/AKZ025/html/all.html
And all I want is the text of the report, between the "FPAK77PAJK" and the "$$". The are so many file functions that I'm overwhelmed. Can anyone recommend a logical way to approach this? Thanks in advance. DM

cave monkey · #2 24-Mar-2004, 12:53

A user on another forum provided me with a solution, using <pre> and </pre> tags that exist in the page, and surround the weather report.

PHP Code:


$str = file_get_contents("http://url");
preg_match("|<pre>(.+)</pre>|si", $str, $m);
 echo nl2br($m[0]);

....worked like a charm, if anyone cares.

erniegerdie · #3 25-Mar-2004, 04:52

Or if your not too up to date on your reg expr's and you just wanted the data inbetween the tags, without the <pre> tags you could use a more generic function, i.e:

PHP Code:


function grabtagdata( $searchstring, $starttag, $endtag ) {
    $endpos = 0;
    $tempstring = strtolower($searchstring); // set string to lowercase for a case insensitive search
    $offset = strlen($starttag);
  while ($startpos = strpos($tempstring, $starttag, $endpos)) {
                $startpos += $offset; // add $offset to remove $starttag from grabbed data
                $endpos = strpos($tempstring, $endtag, $startpos);
                $matchedstring .= substr($searchstring, $startpos, ($endpos-$startpos));    //grab the data inbetween the tags
  }
  return $matchedstring; 
}

$str = file_get_contents("http://pajk.arh.noaa.gov/index.php?fcst=AKZ/AKZ025/html/all.html");
echo nl2br(grabtagdata($str, "<pre>", "</pre>")); //make sure to send tags that are lowercase

You could also have a variation of this function which spat the matched strings into an array and then return the array if need be.

If my code is at all dodgy pls feel free to correct me.

cave monkey · #4 25-Mar-2004, 11:37

Thanks, that worked just as well. I'm just learning this stuff, but have quickly realized there are 101 ways to skin a cat in PHP. Thanks for the code, and I look forward to trying some variations of it in other situations. Thanks again. DM

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file retrieval....reg expression?

Solution found!

Thanks.