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Last updated: Fri, 26 Jan 2007

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# feof

(PHP 3, PHP 4, PHP 5)

feof -- Проверяет, достигнут ли конец файла

## Описание

bool feof ( resource handle )

Функция возвращает `TRUE` в случае, когда дескриптор указывает на достижение конца файла или же если произошла ошибка (включая таймаут сокета), иначе возвращает `FALSE`.

Внимание
Если подключение, открытое при помощи fsockopen() не было закрыто сервером, feof() будет ждать достижения таймаута прежде чем вернуть `TRUE`. Время таймаута по умолчанию равно 60 секундам. Вы можете использовать stream_set_timeout() для того, чтобы изменить это значение.

Указатель на файл должен быть корректным и указывать на файл, успешно открытый функциями fopen() или fsockopen().

add a note User Contributed Notes
feof
cmr at forestfactory dot de
19-Nov-2006 08:57
`Here's solution 3:
<?
$fp = fopen("myfile.txt", "r");
while ( ($current_line = fgets($fp)) !== false ) {
// do stuff to the current line here
}
fclose($fp);
?>
AFAICS fgets() never returns an empty string, so we can also write:
<?
$fp = fopen("myfile.txt", "r");
while ( $current_line = fgets($fp) ) {
// do stuff to the current line here
}
fclose($fp);
?>`
Tom
24-Oct-2006 03:27
`feof() is, in fact, reliable. However, you have to use it carefully in conjunction with fgets(). A common (but incorrect) approach is to try something like this:
<?
$fp = fopen("myfile.txt", "r");
while (!feof($fp)) {
$current_line = fgets($fp);
// do stuff to the current line here
}
fclose($fp);
?>
The problem when processing plain text files is that feof() will not return true after getting the last line of input. You need to try to get input _and fail_ before feof() returns true. You can think of the loop above working like this:
* (merrily looping, getting lines and processing them)
* fgets used to get 2nd to last line
* line is processed
* loop back up -- feof returns false, so do the steps inside the loop
* fgets used to get last line
* line is processed
* loop back up -- since the last call to fgets worked (you got the last line), feof still returns false, so you do the steps inside the loop again
* fgets used to try to get another line (but there's nothing there!)
* your code doesn't realize this, and tries to process this non-existent line (typically by doing the same actions again)
* now when your code loops back up, feof returns true, and your loop ends
There's two ways to solve this:
1. You can put an additional test for feof() inside the loop
2. You can move around your calls to fgets() so that the testing of feof() happens in a better location
Here's solution 1:
<?
$fp = fopen("myfile.txt", "r");
while(!feof($fp)) {
$current_line = fgets($fp);
if (!feof($fp)) {
// process current line
}
}
fclose($fp);
?>
And here's solution 2 (IMHO, more elegant):
<?
$fp = fopen("myfile.txt", "r");
$current_line = fgets($fp);
while (!feof($fp)) {
// process current line
$current_line = fgets($fp);
}
fclose($fp);
?>
FYI, the eof() function in C++ works the exact same way, so this isn't just some weird PHP thing...`
ironoxid at libero dot it
06-Jun-2006 06:52
`I really thought that the feof() was TRUE when the logical file pointer is a EOF.
but no !
we need to read and get an empty record before the eof() reports TRUE.
So
$fp = fopen('test.bin','rb');
while(!feof($fp)) {
$c = fgetc($fp);
// ... do something with $c
echo ftell($fp), ",";
}
echo 'EOF!';
prints for two time the last byte position.
If our file length is 5 byte this code prints
0,1,2,3,4,5,5,EOF!
Because of this, you have to do another check to verify if fgetc really reads another byte (to prevent error on "do something with $c" ^_^).
To prevent errors you have to use this code
$fp = fopen('test.bin','rb');
while(!feof($fp)) {
$c = fgetc($fp);
if($c === false) break;
// ... do something with $c
}
but this is the same of
$fp = fopen('test.bin','rb');
while(($c = fgetc($fp))!==false) {
// ... do something with $c
}
Consequently feof() is simply useless.
Before write this note I want to submit this as a php bug but one php developer said that this does not imply a bug in PHP itself (http://bugs.php.net/bug.php?id=35136&edit=2).
If this is not a bug I think that this need at least to be noticed.
Sorry for my bad english.
Bye ;)`
m a p o p a at g m a i l. c o m
03-Jun-2006 05:58
`you can avoid the infinite loop and filling the error logs
by an simple if statement
Here is the example
$handle = fopen("http://xml.weather.yahoo.com/forecastrss?p=AYXX0008&u=f", "r");
$xml = "";
if ($handle)
{
while (!feof($handle))
{
$xml .= fread($handle, 128);
}
fclose($handle);
}`
01-Jan-2006 06:27
`if you use fseek function to pos the pointer exceed the size the file,feof still return true.so note that when you use feof as the condition of while loop.`
31-Jul-2005 10:21
`if you hit an feof() infinite loop, watch out for resultant humongous logs, they can cripple a site with hard disk usage limits or run up excess usage fees.`
04-Mar-2005 09:02
`if you're worried the file pointer is invalid, TEST IT before you go into your loop... that way it'll never be an infinite loop.`
Johannes
12-Mar-2004 02:47
`I found feof() to be a slow function when using a non-blocking connection.
The function stream_get_meta_data() returns much quicker and has a return field 'eof'.`
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Last updated: Fri, 26 Jan 2007
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