gzseek

Seek on a gz-file pointer

&reftitle.description; `int` `gzseek` `resource` `stream` `int` `offset` `int` `whence` `SEEK_SET`

Sets the file position indicator for the given file pointer to the given offset byte into the file stream. Equivalent to calling (in C) `gzseek(zp, offset, SEEK_SET)`.

If the file is opened for reading, this function is emulated but can be extremely slow. If the file is opened for writing, only forward seeks are supported; `gzseek` then compresses a sequence of zeroes up to the new starting position.

&reftitle.parameters;

`stream`

- The gz-file pointer. It must be valid, and must point to a file successfully opened by `gzopen`.

`offset`

- The seeked offset.

`whence`

- `whence` values are:

  - `SEEK_SET` - Set position equal to `offset` bytes.
  - `SEEK_CUR` - Set position to current location plus `offset`.

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

&reftitle.returnvalues;

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

&reftitle.examples;

### `gzseek` example

    <?php
    $gz = gzopen('somefile.gz', 'r');
    gzseek($gz,2);
    echo gzgetc($gz);
    gzclose($gz);
    ?>

&reftitle.seealso;

- `gztell`
- `gzrewind`