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  • SplFileObject::fseek()

    (PHP 5 >= 5.1.0, PHP 7)

    Seek to a position

    说明

    publicSplFileObject::fseek(int $offset[,int $whence= SEEK_SET]): int

    Seek to a position in the file measured in bytes from the beginning of the file, obtained by adding$offsetto the position specified by$whence.

    参数

    $offset

    The offset. A negative value can be used to move backwards through the file which is useful when SEEK_END is used as the$whencevalue.

    $whence

    $whencevalues are:

    • SEEK_SET- Set position equal to$offsetbytes.
    • SEEK_CUR- Set position to current location plus$offset.
    • SEEK_END- Set position to end-of-file plus$offset.

    If$whenceis not specified, it is assumed to be SEEK_SET.

    返回值

    Returns 0 if the seek was successful,-1 otherwise. Note that seeking past EOF is not considered an error.

    范例

    SplFileObject::fseek() example

    <?php
    $file = new SplFileObject("somefile.txt");
    // Read first line
    $data = $file->fgets();
    // Move back to the beginning of the file
    // Same as $file->rewind();
    $file->fseek(0);
    ?>
    

    参见