fseek

fseek

Seeks on a file pointer

int **fseek** resource $stream int $offset int $whence

Sets the file position indicator for the file referenced by . The new position, measured in bytes from the beginning of the file, is obtained by adding to the position specified by . stream``offset``whence

In general, it is allowed to seek past the end-of-file; if data is then written, reads in any unwritten region between the end-of-file and the sought position will yield bytes with value 0. However, certain streams may not support this behavior, especially when they have an underlying fixed size storage.

stream``offsetThe offset.

   To move to a position before the end-of-file,
   a negative value in the  must be passed and
   the  parameter must be set
   to .
  `offset``whence``SEEK_END`

whence values are:

  `whence``SEEK_SET``offset``SEEK_CUR``offset``SEEK_END``offset`

Upon success, returns ; otherwise, returns . 0``-1

Waarschuwing: > This function was created to imitate the C language function of the same name. Please pay attention to the return values as they differ from what one would expect in PHP.

Voorbeeld: example

<?php

$fp = fopen('somefile.txt', 'r');

// read some data
$data = fgets($fp, 4096);

// move back to the beginning of the file
// same as rewind($fp);
fseek($fp, 0);

?>

Opmerking: > If you have opened the file in append ( or ) mode, any data you write to the file will always be appended, regardless of the file position, and the result of calling will be undefined. a``a+``fseek

Opmerking: > Not all streams support seeking. For those that do not support seeking, forward seeking from the current position is accomplished by reading and discarding data; other forms of seeking will fail.

ftell``rewind