Funkcje Systemu plików
PHP Manual

fseek

(PHP 4, PHP 5)

fseekSeeks on a file pointer

Opis

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.

Parametry

handle

Wskaźnik do systemu plików typu resource jest zazwyczaj tworzony poprzez funkcję 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.

Zwracane wartości

Upon success, returns 0; otherwise, returns -1. Note that seeking past EOF is not considered an error.

Przykłady

Przykład #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);

?>

Notatki

Informacja: 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.

Informacja: May not be used on file pointers returned by fopen() if they use the "http://" or "ftp://" formats. fseek() gives also undefined results for append-only streams (opened with "a" flag).

Zobacz też:


Funkcje Systemu plików
PHP Manual