embedded systems Question 3 Let there be a 16-bit variable called STS that indic

Question

embedded systems

Question 3 Let there be a 16-bit variable called STS that indicates the status of a printer. Bit 1 indicates the instruction to print in b/w or in colors (0 to print in b/w, 1 to print in colors), Bit 2 indicates the instruction to print (printing starts when it is set). Bits 3 - 7 determine the amount of paper required to print. Bits 8 12 indicate the amount of papers available in the tray. Bit 13 indicates if the available paper is enough or not. Bit 14-15 indicates the level of the color cartridges. Write a C/C++ program that continuously checks the status of the printer and does the following If a request to print is issued, the amount of paper should be examined against the available papers. If the number of available papers is less than the request, Bit 13 is set; otherwise, it is cleared, without affecting other bits. The request should also check if color printing is required. If so, the value of the color level indicator should be copied to variable called color_lv, otherwise color Ivl is cleared. Test your code for the following cases and provide a screenshot of STS and color Ivl in the following two different cases a) STS = 0x87DA b) STS 50518

Explanation / Answer

BOOL GetJobs(HANDLE hPrinter, /* Handle to the printer. */

JOB_INFO_2 **ppJobInfo, /* Pointer to be filled. */
int *pcJobs, /* Count of jobs filled. */
DWORD *pStatus) /* Print Queue status. */

{

DWORD cByteNeeded,
nReturned,
cByteUsed;
JOB_INFO_2 *pJobStorage = NULL;
PRINTER_INFO_2 *pPrinterInfo = NULL;

/* Get the buffer size needed. */
if (!GetPrinter(hPrinter, 2, NULL, 0, &cByteNeeded))
{
if (GetLastError() != ERROR_INSUFFICIENT_BUFFER)
return FALSE;
}

pPrinterInfo = (PRINTER_INFO_2 *)malloc(cByteNeeded);
if (!(pPrinterInfo))
/* Failure to allocate memory. */
return FALSE;

/* Get the printer information. */
if (!GetPrinter(hPrinter,
2,
(LPSTR)pPrinterInfo,
cByteNeeded,
&cByteUsed))
{
/* Failure to access the printer. */
free(pPrinterInfo);
pPrinterInfo = NULL;
return FALSE;
}

/* Get job storage space. */
if (!EnumJobs(hPrinter,
0,
pPrinterInfo->cJobs,
2,
NULL,
0,
(LPDWORD)&cByteNeeded,
(LPDWORD)&nReturned))
{
if (GetLastError() != ERROR_INSUFFICIENT_BUFFER)
{
free(pPrinterInfo);
pPrinterInfo = NULL;
return FALSE;
}
}

pJobStorage = (JOB_INFO_2 *)malloc(cByteNeeded);
if (!pJobStorage)
{
/* Failure to allocate Job storage space. */
free(pPrinterInfo);
pPrinterInfo = NULL;
return FALSE;
}

ZeroMemory(pJobStorage, cByteNeeded);

/* Get the list of jobs. */
if (!EnumJobs(hPrinter,
0,
pPrinterInfo->cJobs,
2,
(LPBYTE)pJobStorage,
cByteNeeded,
(LPDWORD)&cByteUsed,
(LPDWORD)&nReturned))
{
free(pPrinterInfo);
free(pJobStorage);
pJobStorage = NULL;
pPrinterInfo = NULL;
return FALSE;
}

/*
* Return the information.
*/
*pcJobs = nReturned;
*pStatus = pPrinterInfo->Status;
*ppJobInfo = pJobStorage;
free(pPrinterInfo);

return TRUE;

}

BOOL IsPrinterError(HANDLE hPrinter)
{

JOB_INFO_2 *pJobs;
int cJobs,
i;
DWORD dwPrinterStatus;

/*
* Get the state information for the Printer Queue and
* the jobs in the Printer Queue.
*/
if (!GetJobs(hPrinter, &pJobs, &cJobs, &dwPrinterStatus))
return FALSE;

/*
* If the Printer reports an error, believe it.
*/
if (dwPrinterStatus &
(PRINTER_STATUS_ERROR |
PRINTER_STATUS_PAPER_JAM |
PRINTER_STATUS_PAPER_OUT |
PRINTER_STATUS_PAPER_PROBLEM |
PRINTER_STATUS_OUTPUT_BIN_FULL |
PRINTER_STATUS_NOT_AVAILABLE |
PRINTER_STATUS_NO_TONER |
PRINTER_STATUS_OUT_OF_MEMORY |
PRINTER_STATUS_OFFLINE |
PRINTER_STATUS_DOOR_OPEN))
{
free( pJobs );
return TRUE;
}

/*
* Find the Job in the Queue that is printing.
*/
for (i=0; i < cJobs; i++)
{
if (pJobs[i].Status & JOB_STATUS_PRINTING)
{
/*
* If the job is in an error state,
* report an error for the printer.
* Code could be inserted here to
* attempt an interpretation of the
* pStatus member as well.

*/
if (pJobs[i].Status &
(JOB_STATUS_ERROR |
JOB_STATUS_OFFLINE |
JOB_STATUS_PAPEROUT |
JOB_STATUS_BLOCKED_DEVQ))
{
free( pJobs );
return TRUE;
}
}
}

/*
* No error condition.
*/
free( pJobs );
return FALSE;

}

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