fgetcsv
For large files, consider using stream_get_line rather than fgets - it can make a significant difference.
$ time yes "This is a test line" | head -1000000 | php -r '$fp=fopen("php://stdin","r"); while($line=stream_get_line($fp,65535,"\n")) { 1; } fclose($fp);'
real 0m1.482s
user 0m1.616s
sys 0m0.152s
$ time yes "This is a test line" | head -1000000 | php -r '$fp=fopen("php://stdin","r"); while($line=fgets($fp,65535)) { 1; } fclose($fp);'
real 0m7.281s
user 0m7.392s
sys 0m0.136s
fgets
(PHP 4, PHP 5)
fgets — Récupère la ligne courante sur laquelle se trouve le pointeur du fichier
Description
string fgets
( resource $handle
[, int $length
] )
Récupère la ligne courante sur laquelle se trouve le pointeur du fichier.
Liste de paramètres
- handle
-
Le pointeur de fichier doit être valide et pointer sur un fichier ouvert avec succès par fopen() ou fsockopen() (et pas encore fermé par fclose()).
- length
-
Lit jusqu'à la taille length - 1 octet depuis le pointeur de fichier handle , ou bien la fin du fichier, ou une nouvelle ligne (qui inclut la valeur retournée), ou encore un EOF (celui qui arrive en premier). Si aucune longueur n'est fournie, la fonction lira le flux jusqu'à la fin de la ligne.
Note: Jusqu'en PHP 4.3.0, le fait d'omettre ce paramètre fait que la fonction lira 1024 octets de la ligne. Si la majorité des lignes du fichier dépassent les 8 ko, il est plus efficace pour votre script de spécifier ce paramètre.
Valeurs de retour
Retourne une chaîne de caractères contenant les length premiers caractères, moins 1 octet depuis le pointeur de fichier handle .
Si une erreur survient, la fonction retourne FALSE.
Historique
| Version | Description |
|---|---|
| 4.3.0 | fgets() est compatible avec les données binaires. |
| 4.2.0 | Le paramètre length devient optionnel. |
Exemples
Exemple #1 Lecture d'un fichier ligne par ligne
<?php
$handle = @fopen("/tmp/inputfile.txt", "r");
if ($handle) {
while (!feof($handle)) {
$buffer = fgets($handle, 4096);
echo $buffer;
}
fclose($handle);
}
?>
Notes
Note: Si vous avez des problèmes avec PHP qui ne reconnaît pas certaines lignes lors de la lecture de fichiers qui ont été créés ou lus sur un MacIntosh, vous pouvez activer l'option de configuration auto_detect_line_endings.
Note: Les programmeurs habitués à la programmation 'C' noteront que fgets() ne se comporte pas comme son équivalent C lors de la rencontre de la fin du fichier.
add a note
User Contributed Notesfgets
Leigh Purdie
13-Oct-2008 08:14
13-Oct-2008 08:14
soapergem at gmail dot com
30-Jul-2008 08:49
30-Jul-2008 08:49
I ran into an issue that took me forever to finally figure out today, and I wanted to post my findings here in case anyone else ever runs into the same thing. I had tried to open a connection using fsockopen to my own server, send some data with fwrite, and then read the response with fgets. The data I sent over included the session ID, which was to be loaded by the page receiving it. Keep in mind that both the sender and receiver URLs were on my same server, and both tried to use the same session ID.
I found that I could do the fwrite part just fine, but that fgets would lock up indefinitely, ignoring any timeout I had set with fsockopen (but thankfully still obeying the max_execution_time limit).
The problem was that while the sending page was trying to do the fgets, it still had the session open. But the receiving page needed session data before it was willing to output anything, thereby creating a deadlock.
The solution I found was to call session_write_close() just prior to sending the request in the sender page, thereby granting access for the receiver to open up the session variables it needed.
julian dot chappell at NOSPAM dot btopenworld dot com
26-Jun-2008 05:14
26-Jun-2008 05:14
Reply to Jerem's note. fgets terminating on chr(10) is correct.
For the sake of you youngsters who have never heard of such things, the protocol for the CRLF pair dates back to the days where the input/output with computers was on teletype machines. A sort of glorified typewriter.
chr(13) is a carriage return (CR), a command which physically moved the type head to the home position and chr(10) is a line feed (LF), which moved the paper up a line.
The standard order in which these were used was CRLF - chr(13)/chr(10) - and both were needed for a line break. Use a CR chr(13) on its own and you would overwrite the beginning of the same line. (Incidentally, this was how bold type was done - print the same thing in the same place twice!). Use LF chr(10) on its own and you would continue printing at the current position across the page but dropped down a line. (Because the paper would move up but the print head remain where it is).
Usage of this protocol has become somewhat sloppy and ill-defined these days for both printers and monitors. Some applications expect a line feed chr(10) on its own and simply assume a carriage return, others still use both but often without observing their distinctly separate functions. So much so that it may sometimes appear that they both do more or less the same thing, you only need one of them, and which to use is purely a matter of personal choice. Wrong on all counts!
fgets terminating on a LF chr(10) is correct as it ensures that the preceding CR chr(13) is included in the line if it is present - and doesn't matter if it isn't. If fgets ever terminated on CR chr(13) as jerem suggests more often than not there would be a LF at the beginning of the next line read.
The prefered use of chr(13) alone as a line break is risky. You might get away with it using your own applications and current printer, but if your file is for general release other people would see the entire output of your file printed on the same line if they use applications that interpret the CRLF pair more correctly. Not what you intended!
jerem-NoSpam-ified at live dot com
18-Apr-2008 05:22
18-Apr-2008 05:22
It's worth noting that this function only assumes chr(10) as a line break, but not chr(13). Personally, I prefer using chr(13) as a line break.
Daniel Klein
25-Jan-2008 05:47
25-Jan-2008 05:47
The file pointer that fgets() uses can also be created with the proc_open() function and used with the stdout pipe created from the executed process.
david_sitller at blackbit dot de
25-Oct-2007 02:32
25-Oct-2007 02:32
If you use the example from the command-description, i recommend to trim the $buffer for further use. The line feed ist still at the end of the line. I saw this when using PHP CLI.
Like this, checking a file-list for existing entries:
$handle = fopen ("/tmp/files.txt", "r");
while (!feof($handle)) {
$buffer = fgets($handle, 4096);
if (file_exists(rtrim($filename,"\n"))) {
echo $buffer;
} else {
echo $buffer." has been removed."
}
fclose ($handle);
anacreo has gmail
18-Sep-2007 11:15
18-Sep-2007 11:15
I'm using this function to modify the header of a large postscript document on copy... Works extremely quickly so far...
function write($filename) {
$fh = fopen($this->sourceps,'r');
$fw = fopen($filename,'w');
while (!feof($fh)) {
$buffer = fgets($fh);
fwrite($fw,$buffer);
if (!$setupfound && ereg("^%%BeginSetup",$buffer)) {
$setupfound++;
if (array_key_exists("$filename",$this->output)) {
foreach ($this->output[$filename] as $function => $value) {
fwrite($fw,$value);
}
}
stream_copy_to_stream($fh,$fw);
}
}
fclose($fw);
fclose($fh);
}
Peter Schlaile
21-Aug-2007 08:36
21-Aug-2007 08:36
fscanf($file, "%s\n") isn't really a good substitution for fgets(), since it will stop parsing at the first whitespace and not at the end of line!
(See the fscanf page for details on this)
David at Weintraub.name
10-Jul-2007 11:23
10-Jul-2007 11:23
There's an error in the documentation:
The file pointer must be valid, and must point to a file successfully opened by fopen() or fsockopen() (and not yet closed by fclose()).
You should also add "popen" and "pclose" to the documentation. I'm a new PHP developer and went to verify that I could use "fgets" on commands that I used with "popen".
d at foo.com
13-Aug-2006 10:03
13-Aug-2006 10:03
For sockets, If you dont want fgets, fgetc etc... to block if theres no data there. set socket_set_blocking(handle,false); and socket_set_blocking(handle,true); to set it back again.
svayn at yahoo dot com
14-Jul-2006 11:21
14-Jul-2006 11:21
fgets is SLOW for scanning through large files. If you don't have PHP 5, use fscanf($file, "%s\n") instead.
sam dot bryan at montal dot com
23-May-2006 11:09
23-May-2006 11:09
An easy way to authenticate Windows Domain users from scripts running on a non-Windows or non-Domain box - pass the submitted username and password to an IMAP service on a Windows machine.
<?php
$server = 'imapserver';
$user = 'user';
$pass = 'pass';
if (authIMAP($user, $pass, $server)) {
echo "yay";
} else {
echo "nay";
}
function authIMAP($user, $pass, $server) {
$connection = fsockopen($server, 143, $errno, $errstr, 30);
if(!$connection) return false;
$output = fgets($connection, 128); // banner
fputs($connection, "1 login $user $pass\r\n");
$output = fgets($connection, 128);
fputs($connection, "2 logout\r\n");
fclose($connection);
if (substr($output, 0, 4) == '1 OK') return true;
return false;
}
?>
24-Mar-2006 06:36
Macintosh line endings mentioned in docs refer to Mac OS Classic. You don't need this setting for interoperability with unixish OS X.
tavernadelleidee[italy]
09-Mar-2006 12:44
09-Mar-2006 12:44
I think that the quickest way of read a (long) file with the rows in reverse order is
<?php
$myfile = 'myfile.txt';
$command = "tac $myfile > /tmp/myfilereversed.txt";
passthru($command);
$ic = 0;
$ic_max = 100; // stops after this number of rows
$handle = fopen("/tmp/myfilereversed.txt", "r");
while (!feof($handle) && ++$ic<=$ic_max) {
$buffer = fgets($handle, 4096);
echo $buffer."<br>";
}
fclose($handle);
?>
It echos the rows while it is reading the file so it is good for long files like logs.
Borgonovo
ecvej
04-Jan-2006 10:20
04-Jan-2006 10:20
I would have expected the same behaviour from these bits of code:-
<?php
/*This times out correctly*/
while (!feof($fp)) {
echo fgets($fp);
}
/*This times out before eof*/
while ($line=fgets($fp)) {
echo $line;
}
/*A reasonable fix is to set a long timeout*/
stream_set_timeout($fp, 180);
while ($line=fgets($fp)) {
echo $line;
}
?>
hackajar <matt> yahoo <trot> com
05-Dec-2005 09:17
05-Dec-2005 09:17
When working with VERY large files, php tends to fall over sideways and die.
Here is a neat way to pull chunks out of a file very fast and won't stop in mid line, but rater at end of last known line. It pulled a 30+ million line 900meg file through in ~ 24 seconds.
NOTE:
$buf just hold current chunk of data to work with. If you try "$buf .=" (note 'dot' in from of '=') to append $buff, script will come to grinding crawl around 100megs of data, so work with current data then move on!
//File to be opened
$file = "huge.file";
//Open file (DON'T USE a+ pointer will be wrong!)
$fp = fopen($file, 'r');
//Read 16meg chunks
$read = 16777216;
//\n Marker
$part = 0;
while(!feof($fp)) {
$rbuf = fread($fp, $read);
for($i=$read;$i > 0 || $n == chr(10);$i--) {
$n=substr($rbuf, $i, 1);
if($n == chr(10))break;
//If we are at the end of the file, just grab the rest and stop loop
elseif(feof($fp)) {
$i = $read;
$buf = substr($rbuf, 0, $i+1);
break;
}
}
//This is the buffer we want to do stuff with, maybe thow to a function?
$buf = substr($rbuf, 0, $i+1);
//Point marker back to last \n point
$part = ftell($fp)-($read-($i+1));
fseek($fp, $part);
}
fclose($fp);
kpeters AT-AT monolithss DEE OH TEE com
01-Dec-2005 02:51
01-Dec-2005 02:51
It appears that fgets() will return FALSE on EOF (before feof has a chance to read it), so this code will throw an exception:
while (!feof($fh)) {
$line = fgets($fh);
if ($line === false) {
throw new Exception("File read error");
}
}
dandrews OVER AT 3dohio DOT com
07-Jan-2005 08:11
07-Jan-2005 08:11
Saku's example may also be used like this:
<?php
@ $pointer = fopen("$DOCUMENT_ROOT/foo.txt", "r"); // the @ suppresses errors so you have to test the pointer for existence
if ($pointer) {
while (!feof($pointer)) {
$preTEXT = fgets($pointer, 999);
// $TEXT .= $preTEXT; this is better for a string
$ATEXT[$I] = $preTEXT; // maybe better as an array
$I++;
}
fclose($pointer);
}
?>
angelo [at] mandato <dot> com
19-Nov-2004 03:43
19-Nov-2004 03:43
Sometimes the strings you want to read from a file are not separated by an end of line character. the C style getline() function solves this. Here is my version:
<?php
function getline( $fp, $delim )
{
$result = "";
while( !feof( $fp ) )
{
$tmp = fgetc( $fp );
if( $tmp == $delim )
return $result;
$result .= $tmp;
}
return $result;
}
// Example:
$fp = fopen("/path/to/file.ext", 'r');
while( !feof($fp) )
{
$str = getline($fp, '|');
// Do something with $str
}
fclose($fp);
?>
lelkesa
04-Nov-2004 11:54
04-Nov-2004 11:54
Note that - afaik - fgets reads a line until it reaches a line feed (\\n). Carriage returns (\\r) aren't processed as line endings.
However, nl2br insterts a <br /> tag before carriage returns as well.
This is useful (but not nice - I must admit) when you want to store a more lines in one.
<?php
function write_lines($text) {
$file = fopen('data.txt', 'a');
fwrite($file, str_replace("\n", ' ', $text)."\n");
fclose($file);
}
function read_all() {
$file = fopen('data.txt', 'r');
while (!feof($file)) {
$line = fgets($file);
echo '<u>Section</u><p>nl2br'.($line).'</p>';
}
fclose($file);
}
?>
Try it.
06-Sep-2004 12:05
If you need to simulate an un-buffered fgets so that stdin doesnt hang there waiting for some input (i.e. it reads only if there is data available) use this :
<?php
function fgets_u($pStdn) {
$pArr = array($pStdn);
if (false === ($num_changed_streams = stream_select($pArr, $write = NULL, $except = NULL, 0))) {
print("\$ 001 Socket Error : UNABLE TO WATCH STDIN.\n");
return FALSE;
} elseif ($num_changed_streams > 0) {
return trim(fgets($pStdn, 1024));
}
}
?>
timr
17-Jun-2004 04:13
17-Jun-2004 04:13
If you need to read an entire file into a string, use file_get_contents(). fgets() is most useful when you need to process the lines of a file separately.
Saku
05-Jun-2004 02:47
05-Jun-2004 02:47
As a beginner I would have liked to see "how to read a file into a string for use later and not only how to directly echo the fgets() result. This is what I derived:
<?php
@ $pointer = fopen("$DOCUMENT_ROOT/foo.txt", "r"); // the @ suppresses errors so you have to test the pointer for existence
if ($pointer) {
while (!feof($pointer)) {
$preTEXT = fgets($pointer, 999);
$TEXT = $TEXT . $preTEXT;
}
fclose($pointer);
}
?>
Pete
23-Feb-2004 01:35
23-Feb-2004 01:35
If you have troubles reading binary data with versions <= 4.3.2 then upgrade to 4.3.3
The binary safe implementation seems to have had bugs which were fixed in 4.3.3