file_desc

    An integer returned by open, creat, dup, or dup2.

 offset

    The offset, specified in bytes. The off_t data type is either a
    32-bit or a 64-bit integer. The 64-bit interface allows for file
    sizes greater than 2 GB, and can be selected at compile time by
    defining the _LARGEFILE feature-test macro as follows:

    CC/DEFINE=_LARGEFILE

 direction

    An integer indicating whether the offset is to be measured
    forward from the beginning of the file (direction=SEEK_SET),
    forward from the current position (direction=SEEK_CUR), or
    backward from the end of the file (direction=SEEK_END).