So far with the file IO we have created the following functionality:

openInputFile PROC ; Opens a file for reading

push edx

INVOKE CreateFileA, edx, GENERIC$\_$READ, NULL, NULL, OPEN$\_$EXISTING, FILE$\_$ATTRIBUTE$\_$NORMAL, NULL

$.$IF eax $!=0$ ; Check if file handle is valid

mov fHandle, eax ; Store file handle

$.$ENDIF

pop edx

ret

openInputFile ENDP

openOutputFile PROC ; Opens a file for writing

push edx

INVOKE CreateFileA, edx, GENERIC$\_$WRITE, NULL, NULL, OPEN$\_$ALWAYS, FILE$\_$ATTRIBUTE$\_$NORMAL, NULL

$.$IF eax $!=0$ ; Check if file handle is valid

mov fHandle, eax ; Store file handle

$.$ENDIF

pop edx

ret

openOutputFile ENDP

closeFile PROC ; Closes the file

push edx

$.$IF fHandle $!=0$ ; Check if file handle is valid

INVOKE CloseHandle, fHandle ; Close the file

mov fHandle, $0$ ; Reset file handle

$.$ENDIF

pop edx

ret

closeFile ENDP

fWriteString PROC ; Writes a null$-$terminated string to the file

push edx

$.$IF fHandle $==0$ ; No handle to the file simply return

jmp EXITOUT

$.$ENDIF

call strLen ; Get the length of the string for writing

INVOKE WriteFile, fHandle, edx, eax, ADDR bytesWritten, NULL

EXITOUT:

pop edx

ret

fWriteString ENDP

fReadFile PROC ; ecx will have number of bytes to read

push ecx

push edx

$.$IF fHandle $==0$ ; No handle to the file simply return

jmp EXITOUT

$.$ENDIF

INVOKE ReadFile, fHandle, edx, ecx, ADDR bytesRead, NULL

mov eax, bytesRead ; Return bytes read in eax

EXITOUT:

pop edx

pop ecx

ret

fReadFile ENDP

fWriteChar PROC

LOCAL outChar : BYTE, bytesWritten : DWORD, fHandle : DWORD

INVOKE CreateFileA, ADDR fName, GENERIC$\_$WRITE, NULL, NULL, OPEN$\_$ALWAYS, FILE$\_$ATTRIBUTE$\_$NORMAL, NULL

mov fHandle, eax

mov outChar, $\text{'}$T$\text{'}$

INVOKE WriteFile, fHandle, ADDR outChar, $1,$ ADDR bytesWritten, NULL

INVOKE CloseHandle, fHandle

ret

fWriteChar ENDP

fReadChar PROC

LOCAL inChar : BYTE, bytesRead : DWORD, fHandle : DWORD

INVOKE CreateFileA, ADDR fName, GENERIC$\_$READ, $0,$ NULL, OPEN$\_$EXISTING, FILE$\_$ATTRIBUTE$\_$NORMAL, NULL

mov fHandle, eax

INVOKE ReadFile, fHandle, ADDR inChar, $1,$ ADDR bytesRead, NULL

INVOKE CloseHandle, fHandle

mov al$,$ inChar

ret

fReadChar ENDP

main PROC

INVOKE fWriteChar

INVOKE fReadChar

openInputFile $-$ Opens file for reading

openOutputFile $-$ Opens file for writing

fWriteString $-$ Writes a null terminated string to the file. This uses a strLength procedure

fReadFile $-$ Reads a number of characters from the file

Please follow the video from the lecture material and create the file IO module shown:

Video $-$ File IO

In the latest lab you created

fReadChar $-$ Reads a single character from the file

fWriteChar $-$ Writes a single character to the file

Add this functionality to the FileIO module above.

Onceworking create the following two procedures

fReadString $-$ This procedure will read characters from the file until a space is encountered.

fReadLine $-$ The procedures will read characters from the file until the carriage return line feed pair is encountered $(0$dh$,0$ah$)$

Both of these procedures should take as an argument the offset of a string to fill in the edx, The eax should return the number of character read. all of this needs to be in assembly language