ReadFileTester.asm

TITLE ReadMap, Authors: Mike Spallino

INCLUDE irvine32.inc
INCLUDE macros.inc

BUFFER_SIZE = 1000

.data
buffer BYTE BUFFER_SIZE DUP(?)
filename    BYTE 80 DUP(0)
fileHandle  HANDLE ?

.code
main proc
	;Read in the map file.
	call ReadMapFile
	exit
main endp

ReadMapFile proc
	mWrite "Enter an input filename: "
	mov	edx,OFFSET filename
	mov	ecx,SIZEOF filename
	call	ReadString

	; Open the file for input.
	mov	edx,OFFSET filename
	call	OpenInputFile
	mov	fileHandle,eax

	; Check for errors.
	cmp	eax,INVALID_HANDLE_VALUE		; error opening file?
	jne	file_ok					; no: skip
	mWrite <"Cannot open file",0dh,0ah>
	jmp	quit						; and quit
	
	file_ok:

		; Read the file into a buffer.
		mov	edx,OFFSET buffer
		mov	ecx,BUFFER_SIZE
		call	ReadFromFile
		jnc	check_buffer_size			; error reading?
		mWrite "Error reading file. "		; yes: show error message
		call	WriteWindowsMsg
		jmp	close_file
	
		check_buffer_size:
			cmp	eax,BUFFER_SIZE			; buffer large enough?
			jb	buf_size_ok				; yes
			mWrite <"Error: Buffer too small for the file",0dh,0ah>
			jmp	quit						; and quit
	
		buf_size_ok:	
			mov	buffer[eax],0		; insert null terminator
			mWrite "File size: "
			call	WriteDec			; display file size
			call	Crlf

			; Display the buffer.
			mWrite <"Buffer:",0dh,0ah,0dh,0ah>
			mov	edx,OFFSET buffer	; display the buffer
			call	WriteString
			call	Crlf

	close_file:
		mov	eax,fileHandle
		call	CloseFile

	quit:
		ret
ReadMapFile endp

end main