ProSoft Technology MVI69-ADM - Manual (Page 262)

Serial Port Library Functions MVI-ADM ♦ 'C' Programmable
Developer's Guide 'C' Programmable Application Development Module
Page 262 of 342 ProSoft Technology, Inc.
February 20, 2013
MVIsp_GetCountUnread
Syntax
int MVIsp_GetCountUnread(int comport, int *count);
Parameters
comport Desired communications port
count Pointer to int to receive unread character count
Description
MVIsp_GetCountUnread returns the number of characters in the receive queue
that are waiting to be read. Since data received from a port is queued after
reception from a serial port, the application may need to determine if all
characters have been read or how many characters remain to be read.
comport is the desired serial port and must be previously opened with
MVIsp_Open.
count points to an int that will receive the number of characters that have been
received from the serial port but not read by the application. If the returned count
is 0, all received data has been read. If it is non-zero, it contains the number of
characters placed into the receive queue after reception from a serial port but
that have not been read from the queue with MVIsp_Getch, MVIsp_Gets, or
MVIsp_GetData.
Return Value
MVI_SUCCESS count retrieved successfully
MVI_ERR_NOACCESS comport has not been opened
MVI_ERR_BADPARAM invalid pointer
Example
int count;
if (MVIsp_GetCountUnread(COM2,&count) == MVI_SUCCESS)
{
if (count == 0)
printf("All chars read\n");
else
printf("%d characters remaining\n",count);
}
See Also
MVIsp_Getch (page 252)
MVIsp_Gets (page 257)
MVIsp_GetData (page 259)