Signature for the write callback.
The signature and semantics match POSIX fwrite() implementations
and can generally be used interchangeably.
\param ptr The address of the write buffer.
\param size The size of the records to be written.
\param nmemb The number of records to be written.
\param handle The handle to the data source.
\retval size_t
The number of records written.
Signature for the write callback. The signature and semantics match POSIX fwrite() implementations and can generally be used interchangeably.
\param ptr The address of the write buffer. \param size The size of the records to be written. \param nmemb The number of records to be written. \param handle The handle to the data source. \retval size_t The number of records written.