DevHlp CloseFile

DevHlp_CloseFile is used by base device drivers to close a file previously opened using DevHlp_OpenFile. This devhlp closes a file opened by DevHlp_OpenFile.

Syntax

C

DevHlp_CloseFile ( PFILEIOINFO pFileClose)

Assembler

LES DI, FileClose
MOV DL, DevHlp_CloseFile

CALL [Device_Help]

Parameters

C

pFILEIOINFO input

Pointer to the FILEIOINFO structure defined as follows

   typedef struct FOPEN {
           PSZ    FileName;   /* (input) pointer to file name */
           ULONG  FileSize;   /* (output) size of file returned by FileOPen */
   } FILEOPEN;

   typedef struct FCLOSE {
           USHORT  reserved   /* reserved */
   } FILECLOSE;

   typedef struct FREAD {
           PBYTE Buffer;      /* (input) pointer to input buffer */
           ULONG ReadSize;    /* (input) number of bytes to read fromfile */
   } FILEREAD;

   typedef struct FREADAT {
           PBYTE Buffer;        /* (input) pointer to input buffer */
           ULONG ReadSize;      /* (input) number of bytes to read from file */
           ULONG StartPosition  /* (input) starting file position relative to
                                    the beginning of the file */
   } FILEREADAT;

   typedef union FILEIOOP {
           struct FOPEN FileOpen;
           struct FCLOSE FileClose;
           struct FREAD FileRead;
           struct FREADAT FileReadAt;
   } FILEIOOP;

   typedef struc _DDFileIo {
           USHORT Length; /* (input) length of imbedded structure */
           FILEIOOP Data; /* (input) imbedded file system operation structure */
   } FILEIOINFO, FAR * PFILEIOINFO

Assembler

ES DI points to a FILEIOINFO structure defined as follows

FILEIOINFO struc ; 
length          dw       2     ; length of imbedded fle system operation structure
                               ; must contain value 2 for CloseFile
FCLOSE struc
reserved        dw       ?     ; reserved
FCLOSE     ends
;
FILEIOINFO ends

Data Structure

; assembler structure
SYICloseFile	struc
length		dw	2	; length of structure (must be 2)
SYICloseFile	ends

Return Code

C

Success Indicator 0 if file was closed.

24 ERROR_BAD_LENGTH

Length in the FILEIOINFO structure is invalid.

Assembler

Results in Assembler

C Clear if the file is closed. AX = zero..

C Set if error. AX = Error Code. Possible errors

24 ERROR_BAD_LENGTH

The length in the FILEIOINFO structure is invalid.

Remarks

DevHlp_FileClose may be called at initialization time only. It provides a primitive interface to the mini-IFS or micro_IFS at initialization.

Using this interface, one file only may be opened at a time. No handle is assigned by open. The file closed is assumed to be the most recent opened using DevHlp_OpenFile.

Valid at INIT time only. See also restrictions of DevHlp_OpenFile.

Example Code

C Sample

#include  "dhcalls.h"

USHORT APIENTRY DevHlp_CloseFile

    ( PFILEIOINFO pFileClose) 

pFILEIOINFO input

    Pointer to the FILEIOINFO structure defined as follows

    typedef struct FOPEN {
            PSZ    FileName;   /* (input) pointer to file name */
            ULONG  FileSize;   /* (output) size of file returned by FileOPen */
    } FILEOPEN;

    typedef struct FCLOSE {
            USHORT  reserved   /* reserved */
    } FILECLOSE;

    typedef struct FREAD {
            PBYTE Buffer;      /* (input) pointer to input buffer */
            ULONG ReadSize;    /* (input) number of bytes to read fromfile */
    } FILEREAD;

    typedef struct FREADAT {
            PBYTE Buffer;        /* (input) pointer to input buffer */
            ULONG ReadSize;      /* (input) number of bytes to read from file */
            ULONG StartPosition  /* (input) starting file position relative to
                                     the beginning of the file */
    } FILEREADAT;

    typedef union FILEIOOP {
            struct FOPEN FileOpen;
            struct FCLOSE FileClose;
            struct FREAD FileRead;
            struct FREADAT FileReadAt;
    } FILEIOOP;

    typedef struc _DDFileIo {
            USHORT Length; /* (input) length of imbedded structure */
            FILEIOOP Data; /* (input) imbedded file system operation structure */
    } FILEIOINFO, FAR * PFILEIOINFO

Assembler

LES DI, FileClose
MOV DL, DevHlp_CloseFile

CALL [Device_Help]