PHP 7.1.0 Release Candidate 4 Released


(PHP 4 >= 4.0.1, PHP 5)

fflushPrzekierowuje wyjście do pliku


bool fflush ( resource $uchwyt )

Ta funkcja wymusza zapis całego zbuforowanego wyjścia do zasobu wskazywanego przez plik uchwyt.



Wskaźnik na plik musi być poprawny i musi wskazywać na plik pomyślnie otwarty przez funkcję fopen() lub fsockopen() (a jednocześnie nie zamknięty jeszcze przez fclose()).

Zwracane wartości

Zwraca TRUE w przypadku powodzenia, FALSE w przypadku błędu.


Przykład #1 Przykład zapisu do pliku używając fflush()


$plik fopen($nazwa_pliku'r+');

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User Contributed Notes 2 notes

jzho327 at cse dot unsw dot edu dot au
13 years ago
Sorry, the note I previously added regarding fflush() has a bug!

when you read file by calling
$fp = fopen("myfile", "a+");

and you wish to read the content, you have to call
rewind($fp) before you attemp to read it. (Silly me) Or else if you tried something like
$fp = fopen("myfile", "a+");
$content = fread($fp);

// show that content is in fact null
if ($content == NULL)
print "but it must be first put to rewind<br>\n";

will result

but it must be first put to rewind.
[new line]

in fact, if you are not careful (like me), and you opened it with
$fp = fopen("myfile", "r+");
$content = fread($fp);
// do something with content
then you tried to again
$content = fread($fp);
without rewind, you'd get NULL again. This sounds trivial, but if you work with several file resources, with freads and fopens everywhere, you can get easily lost. So becareful.
oryan at zareste dot com
10 years ago
Just a note that fflush takes care of the cache already, at least on my server.  Using clearstatcache before reading a previously written file also worked, but lagged the output time much more noticeably (by two or three seconds), probably due to excess cache erasing beyond files.
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