fflush

(PHP 4 >= 4.0.1, PHP 5)

fflush — Força a liberação do buffer para um arquivo

Descrição

bool fflush ( resource $handle )

Esta função força a escrita de toda saída cacheada no buffer do arquivo apontado pelo recurso handle.

Parâmetros

handle: O ponteiro do arquivo tem de ser válido por uma chamada a fopen() ou fsockopen() (e ainda não fechado por fclose()).

Valor Retornado

Retorna TRUE em caso de sucesso ou FALSE em falhas.

add a note User Contributed Notes fflush

oryan at zareste dot com 30-Oct-2005 09:48


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.

jzho327 at cse dot unsw dot edu dot au 26-Jan-2003 05:27


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.

add a note