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Last updated: Fri, 09 May 2008

fgets

(PHP 4, PHP 5)

fgets — Gets line from file pointer

Description

string fgets ( resource $handle [, int $length ] )

Gets a line from file pointer.

Parameters

handle: The file pointer must be valid, and must point to a file successfully opened by fopen() or fsockopen() (and not yet closed by fclose()).
length: Reading ends when length - 1 bytes have been read, on a newline (which is included in the return value), or on EOF (whichever comes first). If no length is specified, it will keep reading from the stream until it reaches the end of the line.

Note: Until PHP 4.3.0, omitting it would assume 1024 as the line length. If the majority of the lines in the file are all larger than 8KB, it is more resource efficient for your script to specify the maximum line length.

Return Values

Returns a string of up to length - 1 bytes read from the file pointed to by handle .

If an error occurs, returns FALSE.

ChangeLog

Version	Description
4.3.0	fgets() is now binary safe
4.2.0	The `length` parameter became optional

Examples

Example #1 Reading a file line by line


<?php
$handle = @fopen("/tmp/inputfile.txt", "r");
if ($handle) {
    while (!feof($handle)) {
        $buffer = fgets($handle, 4096);
        echo $buffer;
    }
    fclose($handle);
}
?>

Notes

Note: If PHP is not properly recognizing the line endings when reading files either on or created by a Macintosh computer, enabling the auto_detect_line_endings run-time configuration option may help resolve the problem.

Note: People used to the 'C' semantics of fgets() should note the difference in how EOF is returned.


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 03:15


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 12:36


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 03:23


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".

JOhn
22-Jun-2007 05:12


I would like to know if there is a way to pull out information from a ,txt file so that it will show only a section of the file in the browser and no the whole file. these are small files of 10 lines but need to be able to pull specific information in the txt file out into the page.



I am new to php and functions and I know how to pull the file into the page but can not seem to get the page to show a character range etc of the information from the file

d at foo.com
13-Aug-2006 02:03


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 03:21


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 03:09


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 10:36


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 04:44


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 02:20


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 01:17


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 06:51


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 12:11


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 07:43


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 03:54


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.

05-Sep-2004 04:05


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));

        }

            

    }



?>

rstefanowski at wi dot ps dot pl
12-Aug-2004 10:03


Take note that fgets() reads 'whole lines'. This means that if a file pointer is in the middle of the line (eg. after fscanf()), fgets() will read the following line, not the remaining part of the currnet line. You could expect it would read until the end of the current line, but it doesn't. It skips to the next full line.

timr
16-Jun-2004 08:13


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
04-Jun-2004 06:47


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);

   }

?>

flame
21-May-2004 09:44


fread is binary safe, if you are stuck with a pre 4.3 version of PHP.

Pete
22-Feb-2004 05:35


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

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