Filesystem Funcții
PHP Manual

fseek

(PHP 4, PHP 5)

fseekSeeks on a file pointer

Descrierea

int fseek ( resource $handle , int $offset [, int $whence = SEEK_SET ] )

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

Parametri

handle

O resursă de tip indicator în sistemul de fișiere care este în mod tipic creată utilizând fopen().

offset

The offset.

To move to a position before the end-of-file, you need to pass a negative value in offset and set whence to SEEK_END.

whence

whence values are:

  • SEEK_SET - Set position equal to offset bytes.
  • SEEK_CUR - Set position to current location plus offset.
  • SEEK_END - Set position to end-of-file plus offset.

Valorile întoarse

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

Exemple

Example #1 fseek() example

<?php

$fp 
fopen('somefile.txt''r');

// read some data
$data fgets($fp4096);

// move back to the beginning of the file
// same as rewind($fp);
fseek($fp0);

?>

Note

Notă:

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

Notă:

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.

Vedeți de asemenea


Filesystem Funcții
PHP Manual