©
本文檔使用 php中文網手册 發布
(PHP 4, PHP 5, PHP 7)
fclose — 关闭一个已打开的文件指针
$handle
)
将 handle
指向的文件关闭。
handle
文件指针必须有效,并且是通过 fopen() 或 fsockopen() 成功打开的。
成功时返回 TRUE
, 或者在失败时返回 FALSE
。
Example #1 一个简单 fclose() 例子
<?php
$handle = fopen ( 'somefile.txt' , 'r' );
fclose ( $handle );
?>
[#1] tom dot vom dot berg at online dot de [2014-04-28 20:38:11]
if you want to daysychain a filehandle through some functions and each function is allowed to close th file you might look in a following function first, if the handle is still valid.
Opening a file, there often will be used a code like
if (!$fh = fopen($filename, $mode)) return false;
But if you possably have closed the file and you want to check that, a smililar statement would not work.
DOES NOT WORK: if (!$fh) end_of_chain();
use beter: if (is_resource($fh)) end_of_chain();
[#2] jgotti [2012-09-07 18:25:41]
In case you have some trouble to properly disconnect some client streams opened with stream_socket_server / stream_select you should give a try to stream_socket_shutdown.
<?php stream_socket_shutdown($clientStream,STREAM_SHUT_RDWR); ?>
[#3] crrodriguez at opensuse dot org [2010-05-11 21:05:36]
Note that since PHP 5.3.2 fclose() no longer unlock open file descriptors at shutdown.
[#4] sineld at sineld dot com [2006-11-23 04:50:13]
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.
[#5] mark at markvange * com [2006-05-04 21:17:56]
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.
[#6] williamhamby at williamhamby dot net [2006-04-07 18:19:37]
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?
[#7] James R. Steel [2005-11-28 09:02:34]
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
[#8] kit dot lester at lycos dot co dot uk [2005-09-18 05:34:14]
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!]
[#9] jricher at jacquesricher dot com [2005-02-01 06:06:30]
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.
[#10] kumar mcmillan [2004-09-30 12:10:27]
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
[#11] daniel7 dot martinez at ps dot ge dot com [2001-09-10 16:06:19]
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.