path

    The name of a file that is to be truncated. This argument must
    point to a pathname that names a regular file for which the
    calling process has write permission.

 length

    The new length of the file in bytes. The off_t type of length is
    either a 64-bit integer or a 32-bit integer. The 64-bit interface
    allows for file sizes greater than 2 gigabytes, and can be
    selected at compile time by defining the _LARGEFILE feature-test
    macro:

    CC/DEFINE=_LARGEFILE