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
.
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
.
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
.
If whence
is not specified, it is assumed to be
SEEK_SET.
Return Values
Upon success, returns 0; otherwise, returns -1. Note that seeking
past EOF is not considered an error.
Examples
Example #1 fseek() 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);
?>
Notes
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.
Note:
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).