osal_file_ops_t::write specifications

Signature

size_t (*write)(
    const void *ptr,
    size_t size,
    size_t nmemb,
    OSAL_FILE *stream,
    osal_file_status_t *st);

Purpose

Write up to nmemb elements of size size from ptr to an open OSAL_FILE through the active OSAL file backend.

Preconditions

• If ptr != NULL, then ptr designates readable storage large enough for the attempted write.
• If stream != NULL, then stream designates a valid OSAL_FILE.
• If stream != NULL, then stream has been opened with a mode compatible with writing.
• If st != NULL, then st designates writable storage for one osal_file_status_t.

Invalid arguments

• ptr must not be NULL.
• stream must not be NULL.
• st must not be NULL.

Success

• Returns the number of elements successfully written.
• Writes data from ptr.
• Sets *st to OSAL_FILE_STATUS_OK.

Failure

• Returns 0 and sets *st to OSAL_FILE_STATUS_INVALID for invalid arguments.
• Returns a value smaller than nmemb and sets *st to a non-OK osal_file_status_t representing the backend write error when a backend write failure occurs.
• Backend write failures are reported through the portable osal_file_status_t status domain.

Ownership

• This operation does not transfer ownership of stream.
• The caller retains ownership of stream on both success and failure.

Notes

• If size == 0 or nmemb == 0, the operation returns 0 and sets *st to OSAL_FILE_STATUS_OK.
• This operation is element-oriented: the returned value is expressed in elements, not bytes.