Purpose

Perform control function on the device specified by the opened device handle.

Calling Sequence

int far pascal FS_IOCTL(psffsi, psffsd, cat, func, pParm, lenMaxParm,
                        plenInOutParm, pData, lenMaxData, plenInOutData)
 
struct sffsi far * psffsi;
struct sffsd far * psffsd;
unsigned short cat;
unsigned short func;
char far * pParm;
unsigned short lenMaxParm;
unsigned short * plenInOutParm;
char far * pData;
unsigned short lenMaxData;
unsigned short * plenInOutData;

Where

psffsi is a pointer to the file-system-independent portion of an open file instance.

psffsd is a pointer to the file-system-dependent portion of an open file instance.

cat is the category of the function to be performed.

func is the function within the category to be performed.

pParm is the address of the application input parameter area.

Addressing of this data area is not validated by the kernel (see FSH_PROBEBUF). A null value indicates that the parameter is unspecified for this function. lenMaxParm is the byte length of the application input parameter area.

If lenMaxParm is 0, *plenInOutParm is 0, and pParm is not null, it means that the data buffer length is unknown due to the request being submitted via an old IOCTL or DosDevIOCtl interface.

plenInOutParm is the pointer to an unsigned short that contains the length of the parameter area in use on input and is set by the FSD to be the length of the parameter area in use on output.

Addressing of this data area is not validated by the kernel (see FSH_PROBEBUF). A null value indicates that the parameter is unspecified for this function.

pData is the address of the application output data area.

Addressing of this data area has not been validated by the kernel (see FSH_PROBEBUF). A null value indicates that the parameter is unspecified for this function.

lenMaxData is the byte length of the application output data area.

If lenMaxData is 0, *plenInOutData is 0, and pData is not null, it means that the data buffer length is unknown due to the request being submitted via an old IOCTL or DosDevIOCtl interface.

plenInOutData is the pointer to an unsigned short that contains the length of the data area in use on input and is set by the FSD to be the length of the data area in use on output.

Addressing of this data area is not validated by the kernel (see FSH_PROBEBUF). A null value indicates that the parameter is unspecified for this function.

Remarks

Note: This entry point's parameter list definition has changed from the 1.x IFS document. If the parameters plenInOutParm and plenInOutData are null, use the lenMax parameters as the buffer sizes sent to any file system helper.