fseek
Seeks on a file pointer
Syntax
fseek ( resource $handle , int $offset [, int $whence = SEEK_SET ] ) : int
Parameters
handle
A file system pointer resource that is typically created using 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
| 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. |
Return
Upon success, returns 0; otherwise, returns -1.
Examples
handle offset = 0
<?
$filename = $_SERVER['DOCUMENT_ROOT'] . '/assets/txt/file.txt';
$mode = 'r';
$handle = fopen($filename, $mode);
// read some data
$data = fgets($handle, 4096);
echo $data . PHP_EOL;
// move to the beginning of the file - same as rewind($handle)
$offset = 0;
fseek($handle, $offset);
// read some data
$data = fgets($handle, 4096);
echo $data;
fclose($handle);
?>
Hello Hello
handle offset = 2
<?
$filename = $_SERVER['DOCUMENT_ROOT'] . '/assets/txt/file.txt';
$mode = 'r';
$handle = fopen($filename, $mode);
// read some data
$data = fgets($handle, 4096);
echo $data . PHP_EOL;
// move to the beginning of the file with an offset of 2
$offset = 2;
fseek($handle, $offset);
// read some data
$data = fgets($handle, 4096);
echo $data;
fclose($handle);
?>
Hello llo
whence | SEEK_SET
<?
$filename = $_SERVER['DOCUMENT_ROOT'] . '/assets/txt/file.txt';
$mode = 'r';
$handle = fopen($filename, $mode);
// read some data
$data = fgets($handle, 4096);
echo $data . PHP_EOL;
// move to the beginning of the file with an offset of 2
$offset = 2;
$whence = SEEK_SET;
fseek($handle, $offset, $whence);
// read some data
$data = fgets($handle, 4096);
echo $data;
fclose($handle);
?>
Hello llo
whence | SEEK_CUR
<?
$filename = $_SERVER['DOCUMENT_ROOT'] . '/assets/txt/file.txt';
$mode = 'r';
$handle = fopen($filename, $mode);
// read some data
$data = fgets($handle, 3);
echo $data . PHP_EOL;
// move to the current location with an offset of 2
$offset = 2;
$whence = SEEK_CUR;
fseek($handle, $offset, $whence);
// read some data
$data = fgets($handle, 4096);
echo $data;
fclose($handle);
?>
He o
whence | SEEK_END
<?
$filename = $_SERVER['DOCUMENT_ROOT'] . '/assets/txt/file.txt';
$mode = 'r';
$handle = fopen($filename, $mode);
// read some data
$data = fgets($handle, 4096);
echo $data . PHP_EOL;
// move to the end of the file with an offset of 2
$offset = -2;
$whence = SEEK_END;
fseek($handle, $offset, $whence);
// read some data
$data = fgets($handle, 4096);
echo $data;
fclose($handle);
?>
Hello lo
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