PHP fseek function

Like this blog? Consider exploring one of our sponsored banner ads...

fseek

(PHP 3, PHP 4, PHP 5)

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, whose values are defined as
follows:

If whence is not specified, it is assumed to be
SEEK_SET.

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

Example 1. fseek() example

 
$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);

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).

Note:
The whence argument was added after PHP 4.0.0.

Note:
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.

See also ftell() and
rewind().