Purpose
DosListIO performs the specified number of seek/read and/or seek/write operations.
Syntax
#define INCL_DOSFILEMGR #include os2.h>
APIRET DosListIO
Parameters
CmdMode (ULONG) input
LISTIO_ORDERED
Returns
ulrc (APIRET) returns
DosListIO returns one of the following values
19
Remarks
DosListIO applies the same restrictions for each seek/read and seek/write control block as would be applied if the requests were issued separately with DosSetFilePtr, DosRead, and DosWrite.
Each request control block contains fields for the Actual number of bytes read/written and the operation return code. These fields are updated upon completion of each request, therefore care must be taken that the memory containing the control block array not be deallocated or manipulated by another thread before the DosListIO request returns.
There are two valid modes for the list of I/O operations to be processed
Related Functions
Example Code
The following is NOT a complete usable program. It is simply intended to provide an idea of how to use Raw I/O File System APIs (e.g. DosOpen, DosListIO, and DosClose).
This example opens physical disk #1 for reading and physical disk #2 for writing. Using DosListIO, 10 megabytes of data is transferred disk #1 to disk #2. Finally, DosClosed is issued to close the disk handles.
It is assumed that the size of each of the two disks is at least 10 megabytes.
#define INCL_DOSFILEMGR /* Include File Manager APIs */#define INCL_DOSMEMMGR /* Includes Memory Management APIs */
#define INCL_DOSERRORS /* DOS Error values */
#include os2.h>
#include stdio.h>
#include stdlib.h>
#include string.h>
#define SIXTY_FOUR_K 0x10000
#define ONE_MEG 0x100000
#define TEN_MEG 10*ONE_MEG
#define UNC_DISK1 "\\\\.\\Physical_Disk1"
#define UNC_DISK2 "\\\\.\\Physical_Disk2"
int main(void) {
LISTIO listIOCtrlBlks[2]; /* List IO control blocks */
ULONG ulNumCtrlBlks; /* Number of control blocks */
HFILE hfDisk1 = 0; /* Handle for disk #1 */
HFILE hfDisk2 = 0; /* Handle for disk #2 */
ULONG ulAction = 0; /* Action taken by DosOpen */
UCHAR uchFileName1[20] = UNC_DISK1, /* UNC Name of disk 1 */
uchFileName2[20] = UNC_DISK2; /* UNC Name of disk 2 */
PBYTE pBuffer = 0;
ULONG cbTotal = 0;
APIRET rc = NO_ERROR; /* Return code */
/* Open a raw file system disk #1 for reading */
rc = DosOpen(uchFileName1, /* File name */
hfDisk1, /* File handle */
ulAction, /* Action taken by DosOpen */
0L, /* no file size */
FILE_NORMAL, /* File attribute */
OPEN_ACTION_OPEN_IF_EXISTS, /* Open existing disk */
OPEN_SHARE_DENYNONE | /* Access mode */
OPEN_ACCESS_READONLY,
0L); /* No extented attributes */
if (rc != NO_ERROR) {
printf("DosOpen error rc = %u\n", rc);
return(1);
} /* endif */
/* Open a raw file system disk #2 for writing */
rc = DosOpen(uchFileName2, /* File name */
hfDisk2, /* File handle */
ulAction, /* Action taken by DosOpen */
0L, /* no file size */
FILE_NORMAL, /* File attribute */
OPEN_ACTION_OPEN_IF_EXISTS, /* Open existing disk */
OPEN_SHARE_DENYNONE | /* Access mode */
OPEN_ACCESS_READWRITE,
0L); /* No extented attributes */
if (rc != NO_ERROR) {
printf("DosOpen error rc = %u\n", rc);
return(1);
} /* endif */
/* Allocate 64K of memory for transfer operations */
rc = DosAllocMem((PPVOID) pBuffer, /* Pointer to buffer */
SIXTY_FOUR_K, /* Buffer size */
PAG_COMMIT | /* Allocation flags */
PAG_READ |
PAG_WRITE);
if (rc != NO_ERROR) {
printf("DosAllocMem error rc = %u\n", rc);
return(1);
} /* endif */
/* Initialize listIO control blocks */
memset(listIOCtrlBlks, 0, sizeof(listIOCtrlBlks));
listIOCtrlBlks[0].hFile = hfDisk1; /* Handle for disk 1 */
listIOCtrlBlks[0].CmdFlag = LISTIO_READ | /* Read operation */
FILE_CURRENT;
listIOCtrlBlks[0].Offset = 0;
listIOCtrlBlks[0].pBuffer = (PVOID)pBuffer;
listIOCtrlBlks[0].NumBytes = SIXTY_FOUR_K;
listIOCtrlBlks[1].hFile = hfDisk2; /* Handle for disk 2 */
listIOCtrlBlks[1].CmdFlag = LISTIO_WRITE | /* Write operation */
FILE_CURRENT;
listIOCtrlBlks[1].Offset = 0;
listIOCtrlBlks[1].pBuffer = (PVOID)pBuffer;
listIOCtrlBlks[1].NumBytes = SIXTY_FOUR_K;
while (cbTotal TEN_MEG) {
ulNumCtrlBlks = 2;
rc = DosListIO(LISTIO_ORDERED,
ulNumCtrlBlks,
listIOCtrlBlks);
if (rc != NO_ERROR) {
printf("DosListIO error rc = %u\n", rc);
break;
} else {
/* Check return code from the read operation */
if (listIOCtrlBlks[0].RetCode != NO_ERROR) {
printf("DosListIO read operation failed, rc = %u\n",
listIOCtrlBlks[0].RetCode);
return 1;
}
/* Check return code from the write operation */
if (listIOCtrlBlks[0].RetCode != NO_ERROR) {
printf("DosListIO write operation failed, rc = %u\n",
listIOCtrlBlks[0].RetCode);
return 1;
}
}
if (listIOCtrlBlks[0].Actual != listIOCtrlBlks[1].Actual) {
printf("Bytes read (%u) does not equal bytes written (%u)\n",
listIOCtrlBlks[0].Actual, listIOCtrlBlks[1].Actual);
return 1;
}
cbTotal += SIXTY_FOUR_K; /* Update total transferred */
} /* end while */
printf("Transfer successfully %d bytes from disk #1 to disk #2.\n",
cbTotal);
/* Free allocated memmory */
rc = DosFreeMem(pBuffer);
if (rc != NO_ERROR) {
printf("DosFreeMem error return code = %u\n", rc);
return 1;
}
rc = DosClose(hfDisk1);
if (rc != NO_ERROR) {
printf("DosClose error return code = %u\n", rc);
return 1;
}
rc = DosClose(hfDisk2);
if (rc != NO_ERROR) {
printf("DosClose error return code = %u\n", rc);
return 1;
}
return NO_ERROR;
}