on file() and flock()
My supervisor came up with a brilliant plan to workaround the inability of the file() to work on a flock()'ed file.
We created a dummy file called lockfile.txt. We would flock() lockfile.txt. Once we had a lock on it, we used file() on the file we wanted to read, then altered the file and called fclose on both files.
file
(PHP 4, PHP 5)
file — Legge l'intero file in un vettore
Descrizione
Identica a readfile(), eccetto per il fatto che file() restituisce il file in un vettore. Ogni elemento del vettore corrisponde ad una riga del file, con il carattere di newline ancora inserito. Se la funzione non riesce restituisce FALSE.
Puoi impostare il secondo parametro, use_include_path , (opzionale) ad "1", se vuoi cercare il file nel include_path.
<?php
// inserisce una pagina web in un array e la stampa. In questo esempio useremo il protocollo
// HTTP per ottenere il sorgente di un URL
$lines = file('http://www.example.com/');
// Ciclo attraverso l'array, si visualizzerà il sorgente come html ed i numeri di linea
foreach($lines as $line_num => $line) {
echo "Line #<b>{$line_num}</b> : " . htmlspecialchars($line) . "<br />\n";
}
// Un'altro esempio, inserisce la pagina web in una stringa. Vedere anche file_get_contents().
$html = implode('', file ('http://www.example.com/'));
?>
È possibile utilizzare una URL come un nome di file con questa funzione se fopen wrappers è stata abilitata. Per maggiori informazioni su come specificare i nomi di file vedere fopen() e List of Supported Protocols/Wrappers per avere la lista dei protocolli URL supportati.
Nota: Ciascuna riga dell'array restituito conterrà il carattere di fine riga, occorre, pertanto, utilizzare rtrim() se si desidera rimuovere il carattere di fine riga.
Nota: Se si hanno problemi con il PHP che non riconosce i fine linea leggendo file creati o ospitati su un computer Macintosh, si può abilitare l'opzione auto_detect_line_endings della configurazione di runtime.
Nota: A partire da PHP 4.3.0 si può utilizzare file_get_contents() per memorizzare il contenuto di un file in una stringa in formato binario.
Nota: Il supporto per il contesto è stato aggiunto in PHP 5.0.0. Per la descrizione del contesto, fare riferimento a Stream Funzioni.
Quando si usa SSL, Microsoft IIS viola il protocollo chiudendo la connessione senza inviare un indicazione close_notify. PHP indicherà questo con un "SSL: Fatal Protocol Error" al raggiungimento della fine dei dati. Per aggirare questo problema, occorre abbassare il livello error_reporting per non includere questi avvisi. PHP 4.3.7 e successivi sono in grado di identificare gli IIS bacati quando si apre lo stream utilizzando il wrapper https:// e disabilitano automaticamente l'avviso. Se si usa fsockopen() per creare un socket ssl:// , occorre identificare e sopprimetre l'avviso manualmente.
Vedere anche readfile(), fopen(), fsockopen(), popen(), file_get_contents() e include().
file
22-Apr-2008 12:49
16-Apr-2008 10:03
A user suggested using rtrim always, due to the line ending conflict with files that have an EOL that differs from the server EOL.
Using rtrim with it's default character replacement is a bad solution though, as it removes all whitespace in addition to the '\r' and '\n' characters.
A good solution using rtrim follows:
<?php
$line = rtrim($line, "\r\n") . PHP_EOL;
?>
This removes only EOL characters, and replaces with the server's EOL character, thus making preg_* work fine when matching the EOL ($)
05-Apr-2008 12:45
althought it's mentioned twice in the description, it took me a whole night to figure out why i got new-lines in my array.
hence you have to put a flag on it FILE_IGNORE_NEW_LINES.
I mention, just you wouldn't miss this little anoying thing.
*you can use trim, but it's slighty different.
16-Feb-2008 10:15
If you're getting "failed to open stream: Permission denied" when trying to use either file() or fopen() to access files on another server. Check your host doesn't have any firewall restrictions in-place which prevent outbound connections. This is the case with my host Aplus.net
12-Jul-2007 11:25
This note applies to PHP 5.1.6 under Windows (although may apply to other versions).
It appears that the 'FILE_IGNORE_NEW_LINES' flag doesn't remove newlines properly when reading Windows-style text files, i.e. files whose lines end in '\r\n'.
Solution: Always use 'rtrim()' in preference to 'FILE_IGNORE_NEW_LINES'.
28-Nov-2006 09:33
Using file() for reading large text files > 10 Mb gives problems, therefore you should use this instead. It is much slower but it works fine. $lines will return an array with all the lines.
$handle = @fopen('yourfile...', "r");
if ($handle) {
while (!feof($handle)) {
$lines[] = fgets($handle, 4096);
}
fclose($handle);
}
11-Jul-2006 11:19
justin at visunet dot ie's note of 20-Mar-2003 states
"Note: Now that file() is binary safe it is 'much' slower than it used to be. If you are planning to read large files it may be worth your while using fgets() instead of file()."
I tested fgets(), file_get_contents(), and file() on PHP 4.3.2 and PHP 5 and timed each to be under a second with over 200,000 lines. I do not know if he was testing extremely long lines or what, but I could not duplicate the difference that he mentioned.
01-Feb-2006 11:52
you can use
$file = array_map('rtrim',file('myfile.txt'));
to remove annoying ending lines of the resulting array.
19-Jan-2006 12:16
WARNING ON WINDOWS:
file() function will add "\r\n" in to the end of the row, even if you use only "\n" char to make rows in the file!
On UNIX systems there is no such problem.
12-Sep-2003 11:48
Jeff's array2file function is a good start; here are a couple of improvements (no possibility of handle leak when fwrite fails, additional capability of both string2file and array2file; presumably faster performance through use of implode).
function String2File($sIn, $sFileOut) {
$rc = false;
do {
if (!($f = fopen($sFileOut, "wa+"))) {
$rc = 1; break;
}
if (!fwrite($f, $sIn)) {
$rc = 2; break;
}
$rc = true;
} while (0);
if ($f) {
fclose($f);
}
return ($rc);
}
function Array2File($aIn, $sFileOut) {
return (String2File(implode("\n", $aIn), $sFileOut));
}
If you're generating your string text using a GET or POST from a TEXTAREA (e.g., a mini-web-text-editor), remember that strip_slashes and str_replace of "/r/n" to "/n" may be necessary as well using these functions.
HTH --dir @ badblue com
21-Jul-2003 01:32
after many months of confusion and frustration, i have finally figured out something that i should have noticed the first time around.
you can't file("test.txt") when that same file has been flocked. i guess i didn't have a full understanding of what i was doing when i used flock(). all i had to do was move the flock() around, and all was well.
20-Mar-2003 06:36
Note: Now that file() is binary safe it is 'much' slower than it used to be. If you are planning to read large files it may be worth your while using fgets() instead of file() For example:
$fd = fopen ("log_file.txt", "r");
while (!feof ($fd))
{
$buffer = fgets($fd, 4096);
$lines[] = $buffer;
}
fclose ($fd);
The resulting array is $lines.
I did a test on a 200,000 line file. It took seconds with fgets() compared to minutes with file().
You can use file with https if you go to:
http://ftp.proventum.net/pub/php/win32/misc/openssl/.
This is instead of using the php_openssl.dll, so be sure to comment this extension in your php.ini.
16-Mar-2002 08:16
file() has a strange behaviour when reading file with both \n and \r as line delimitator (DOS files), since it will return an array with every single line but with just a \n in the end. It seems like \r just disappears.
This is happening with PHP 4.0.4 for OS/2. Don't know about the Windows version.
09-Feb-2002 09:56
It appears that the file() function causes file access problems for perl cgi scripts accessing the same files. I am using Perl v5.6.0 in linux with PHP/4.0.4pl1. After running a php app using the file() function, any perl cgi trying to access the same file randomly dies returning an internal server error: premature end of script headers.
The simple fix is to use fopen(), fgets() and fclose() instead of file().
