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(PHP 4, PHP 5)
fclose — Schließt einen offenen Dateizeiger
Die Datei, auf die handle zeigt, wird geschlossen.
Der Datei-Zeiger muss gültig sein, d.h. die Datei, auf die gezeigt wird muss zuvor mit fopen() oder fsockopen() geöffnet worden sein.
Gibt bei Erfolg TRUE zurück. Im Fehlerfall wird FALSE zurückgegeben.
Beispiel #1 Ein einfaches fclose() Beispiel
<?php
$handle = fopen('somefile.txt', 'r');
fclose($handle);
?>
Note that since PHP 5.3.2 fclose() no longer unlock open file descriptors at shutdown.
Do not forget, if you are going to read the contents of the file which you have already written via fwrite() or else you have to close the file first.
It is very important to make sure you clear any incoming packets out of the incoming buffer using fread() or some equivalent. Although you can call fclose() the socket does not actually shut down until the inbound packets have been cleared. This can lead to some confusion.
Trying to understand how 'end foreach' and 'endwhile' differ, I've encountered a problem I can't solve by myself. The following is a fairly easy stock portfolio script. Everything works, except at the end where I want to calculate the average of the gains as represented by $gain[$i].
<?php
$quantity="3";
$stocks=array("iso","grn","bdgr.pk");
$buydates=array("3 jan 2006","1 feb 2006","3 apr 2006");
$prices=array("0.32","0.20","0.95");
$recommends=array("hold","strong buy","buy");
$i=0;
echo"<tr>";
echo "\n<th align='center'>ticker</th>";
echo "\n<th align='center'>buy date</th>";
echo "\n<th align='center'>price $</th>";
echo "\n<th align='center'>recommend</th>";
echo "\n<th align='center'>value $</th>";
echo "\n<th align='center'>change %</th>\n</tr>\n";
foreach($stocks as $stock) {
$fp=fopen("http://","r");
$data=fgetcsv($fp,1000,",");
$values=$data[1];
echo "<tr>\n<td align='center'>".$stock."</td>";
echo "\n<td align='center'>".$buydates[$i]."</td>";
echo "\n<td align='center'>".$prices[$i]."</td>";
echo "\n<td align='center'>".$recommends[$i]."</td>";
echo "\n<td align='center'>".$values."</td>\n<td align='center'>";
echo $gain[$i]=round(((($values-$prices[$i])/$prices[$i])*100),2);
echo "</td>\n</tr>";
fclose ($fp);
$i++;
}
echo "\n<tr>\n<td align='center'>".$gain[$i]."<td>\n</tr>\n";
?>
Help?
In response to kumar mcmillan 'gotcha' note below, we get a different result on a W2K machine:
<?php
$file_pointer = fopen('textfile.dat', 'r');
fclose($file_pointer);
echo '$file_pointer is resource = ' . (is_resource($file_pointer) ? 'true': 'false');
?>
output:
$file_pointer is resource = false
fclose() also clears any locks on the file, so if another process was being kept waiting for the lock to be cleared, fclose()ing will allow the other process to continue.
[Another "just-in-case" reason to habitually fclose() all files as soon as practical!]
It is a GOOD_THING to check the return value from fclose(), as some operating systems only flush file output on close, and can, therefore, return an error from fclose(). You can catch severe data-eating errors by doing this.
I learned this the hard way.
gotcha:
<?php
$file_pointer = fopen('data.dat', 'r');
fclose($file_pointer);
echo '$file_pointer is resource = ' . (is_resource($file_pointer) ? 'true': 'false');
?>
output:
$file_pointer is resource = true
Generally, it's always a good idea to close a file when you're done with it. It's very easy for something to go wrong and corrupt a file that hasn't been closed properly. If you're concerned about efficiency, the overhead is negligible.
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