ftruncate 


php128 apg

TRUNCATES a file to a given length.





If $size is larger than the file then the file is extended with null bytes.

If $size is smaller than the file then the file is truncated to that $size.

This function upon success, returns TRUE, otherwise, returns FALSE.



<?php

bool ftruncate ( res $stream , int $size )


where,

$stream = A file system pointer

$size = The size to truncate to

?>

 $stream 


A file system pointer typically created by fopen.



  $size   


The size to truncate to.



  1 EXERCISE   

<?php

$dir01 = __DIR__ . '/temp/';

$file01a = 'blahblahblah.txt';

$file01b = $dir01 . $file01a;

$fp01 = fopen($file01b, 'r');

$len01 = filesize($file01b);

$rnd01 = mt_rand(1, $len01);

ftruncate($fp01, $rnd01);

rewind($fp01);

echo fread($fp01, $len01);

fclose($fp01);

?>

  2 EXERCISE   

<?php

/* 

  Run this exercise several times
  For each new run a new result will be obtained
  
  This function may be difficult to display 
  for accented characters in the last position

*/

$dir02 = __DIR__ . '/temp/';

$file02a = 'blahblahblah.txt';

$file02b = $dir02 . $file02a;

$fp02 = fopen($file02b, 'r');

rewind($fp02);

$len02 = mt_rand(1, 200);

ftruncate($fp02, $len02);

rewind($fp02);

$fread02 = fread($fp02, $len02);

echo $fread02 . "<br><br>";

var_dump($fp02);

echo "<br><br>" . $len02 . ' characters read.';

fclose($fp02);

?>