ED: Gotten l (list) working, need to work more on d (delete) as there's a bug with deleting lines that are not line 1.

data/test.asm

@@ -0,0 +1,2 @@
+X = 100
+PRINT X

source/kernel/features/cli.asm

@@ -1,5 +1,6 @@
 os_start_cli:
 	pusha
+
 	
 	call os_print_newline
 
@@ -67,14 +68,14 @@ os_read_cli:
 	call os_compare_strings
 	cmp cl, 1
 	je .ls
-
+	
-    ; ED
+    ;ED 
 	mov si, user_input
 	mov di, ed_string
 	call os_compare_strings
 	cmp cl, 1
 	je .ed
-	
+
 	jmp .unkown
 
 .unkown:
@@ -85,6 +86,11 @@ os_read_cli:
 	jmp .finish
 
 .finish:
+	; Clear the user input
+	mov al, 0
+	mov cx, 20
+	mov di,user_input 
+	repe stosb
 	popa
 	call os_start_cli
 

source/kernel/features/disk.asm

@@ -171,7 +171,7 @@ disk_clear_output_buffer:
 ; OUT
 ; data_buffer: file contents
 ; TODO use predefined data for calculations
-; carry flag: set if failed to load file
+; CX = 0 if failed to load
 disk_load_file:
    pusha
    call string_length ; cl = string length
@@ -235,10 +235,11 @@ disk_load_file:
    jmp .done_fail
 .done_fail:
 	popa
-	stc
+	mov bx, 1
 	ret
 .done:
    popa
+	xor bx,bx
    ret
 
 ; Write data to file

source/kernel/features/keyboard.asm

@@ -28,6 +28,8 @@ keyboard_check_key:
 ; IN:
 ; AX = output address
 ; BX = max length
+; OUT:
+; BX = 1 if escape is pressed
 keyboard_display_input:
 	pusha
 	mov di, ax
@@ -55,14 +57,15 @@ keyboard_display_input:
 		jmp .check_key_pressed
 
 	.esc_key:
-		stc
 		popa
+		mov bx, 1
 		ret
 
 	.enter_key:
 		mov al, 0
 		stosb
 		popa
+		xor bx,bx
 		ret ; Return to the parent function (whatever that may be)
 
 	.backspace:

source/kernel/features/strings.asm

@@ -106,39 +106,42 @@ string_join:
 		ret
 
 ; ------------------------------------------------------------------------
-; TODO
 ; Converts a string to an integer
 ; IN: SI = string location (max 5 chars, up to '65536')
-; OUT: AX = number
+; OUT: AX = number, DX = length of int string
 string_cast_to_int:
-	pusha
+	push cx
+	push bx
+	push dx
 	xor cx,cx
 	.loop:
 		xor ax,ax
 		lodsb
 
-		cmp al, 30h
+		; Exit if the character is not a number
+		cmp al,'0'
 		jl .finish
-		cmp al, 39h
+		cmp al,'9'
 		jg .finish
-
+		
-		sub al, 30h
+		sub al, '0'
 		mov bx, ax
+
 		mov ax, 10
 		mul cx ; Multiple the current value by 10
 		add ax, bx ; Then add the new digit
 		mov cx, ax
 		jmp .loop
 	.finish:
-		mov [int_tmp], cx
+		mov ax,cx
-		popa
+		pop dx
-		mov ax, [int_tmp]
+		pop bx
+		pop cx
 		ret
 
 ; ------------------------------------------------------------------------
 ; IN:  AX = integer (unsigned)
 ; OUT: AX -> null-terminated string
-
 string_cast_from_int:
 	pusha
 	cld ; Write backwards

source/kernel/features/text.asm

@@ -55,10 +55,16 @@ text_print_raw:
 		je .space
 		cmp al, 0Ah	; When there's an NL or CR, do both, linux encodes files only with NL
 		je .new_line
+		cmp al, 09h ; TAB
+		je .tab
 		cmp al, 0Dh
 		je .repeat
 		int 10h
 		jmp .repeat
+	.tab:
+		mov al, ' '
+		int 10h
+		jmp .repeat
 	.space:
 		mov al, 20h
 		int 10h
@@ -68,9 +74,6 @@ text_print_raw:
 		int 10h
 		mov al, 0Dh
 		int 10h
-		push ax
-		call os_read_input ; wait until key is pressed until it prints the next line
-		pop ax
 		jmp .repeat
 	.finish:
 		popa
@@ -132,6 +135,15 @@ os_set_text_mode:
 	mov dh, 0
 	mov dl, 0
 	int 10h
+
+text_newline:
+	pusha
+	mov ax,0E0Ah
+	int 10h
+	mov al,0Dh
+	int 10h
+	popa
+	ret
 
 	popa
 	ret

source/kernel/features/utils.asm

@@ -7,7 +7,8 @@ util_cat:
 	add si, 4   ; Move si to after 'CAT'
 
 	call disk_load_file
-	jc .done ; if file failed to load, just quit
+	cmp bx, 1
+	je .done
 
 	mov si, file_buffer
 	mov cx, [file_length]
@@ -36,7 +37,8 @@ util_basic:
 	; TODO make this more consistent to account for double spaces
 	;add si, 3 ; Move si to after 'BAS'
 	call disk_load_file
-	jc .done
+	cmp bx, 1
+	je .done
 
 	mov si, file_buffer
 

source/kernel/programs/ed.asm

@@ -1,21 +1,34 @@
 ; Planned commands:
-; i insert
+; [ ] i insert
-; a append
+; [ ] a append
-; d delete
+; [-] d delete
-; l prints lines
+; [x] l prints lines
-; w save to disk
+; [ ] w save to disk
-; q quit
+; [x] q quit
 ed:
 	pusha
-	call .determine_line_count
+	call determine_line_count
 	.main_loop:
+		; CLEAR VARIABLES
+		mov [ed_start_int], 0
+		mov [ed_end_int], 0
+		mov [ed_operation_from], 0
+		mov [ed_operation_by], 0
+
+		; Setup prompt
 		mov ax, ed_prompt
 		mov bx, 40
 		call keyboard_display_input ; AX = string location, BX = max prompt length
+		cmp bx, 1 ; I user pressed escape
+		je .quit
 		mov si, ed_prompt
 		mov bx, 0 ; Keeps track of whether comma has passed
 		jmp .get_token
 
+	.error:
+		call ed_error
+		jmp .main_loop
+
 	; Types of tokens:
 	; Number: eg 123
 	; Doller (refers to the last line) $
@@ -29,6 +42,10 @@ ed:
 		cmp al, ','
 		je .comma
 
+		; DOLLAR SIGN
+		cmp al, '$'
+		je .dollar
+
 		; NUMBER
 		call check_is_number
 		jc .get_number_token
@@ -36,24 +53,17 @@ ed:
 		; COMMAND
 		call check_is_letter
 		jc .get_letter_token
-
+		jmp .error
-	.error: ; Output ?
-		mov ah, 0Eh
-
-		mov al, '?'
-		int 10h
-		mov al, 0Ah
-		int 10h
-		mov al, 0Dh
-		int 10h
-		
-		jmp .main_loop
 
 	; Assign a number to either the start or end int (start,end)
+	.dollar:
+		mov ax, [ed_line_count]
+		inc si ; Cancel out the last dec si 
+		jmp .after_int_cast
 	.get_number_token:
-		push si
 		dec si
-		call string_cast_to_int ; AX = integer
+		call string_cast_to_int ; AX = integer, DX = length of int string
+	.after_int_cast:
 		cmp bx, 0
 		je .assign_start_int
 		jg .assign_end_int
@@ -62,97 +72,208 @@ ed:
 		jmp .after_int_assign
 	.assign_end_int:
 		mov [ed_end_int], ax
+
+		; Check it's not after the end of the file
+		cmp ax, [ed_line_count]
+		jg .error
+		; Check it's not less than the start int
+		cmp ax, [ed_start_int]
+		jl .error 
 	.after_int_assign:
-		pop si
+		dec si
 		jmp .get_token
 
+
 	; Determines a command
 	.get_letter_token:
+		; If ed int
+		cmp [ed_end_int], 0
+		je .set_end_int
+	.after_end_int_check:
+		cmp al, 'l'
+		je .list
 		cmp al, 'd'
 		je .delete
 		cmp al, 'q'
 		je .quit
-		jmp .get_token
+		call ed_error
+		jmp .main_loop
+	; If no end int is assigned, set it to the start int
+	.set_end_int:
+		cmp bx,0
+		push ax
+		jne .end_int_to_end ; If , has been passed
+	.end_int_to_start_int:
+		mov ax, [ed_start_int]
+		mov [ed_end_int], ax
+		pop ax
+		jmp .after_end_int_check
+	.end_int_to_end:
+		mov ax, [ed_line_count]
+		mov [ed_end_int], ax
+		pop ax
+		jmp .after_end_int_check
+
 
 	; Changes the value from start int to end int
 	.comma:
 		mov bx, 1
 		jmp .get_token
 
-	.determine_line_count:
-		mov si, file_buffer
-		mov dx, file_length ; STORES THE LENGTH OF THE FILE IN BYTES
-		xor cx,cx
-		.line_count_loop:
-			lodsb
-			cmp al, 0Ah
-			je .increment_line_count
-			dec dx
-			cmp dx, 0
-			jg .line_count_loop
-		mov [ed_line_count], cx
-		jmp .main_loop
-		.increment_line_count:
-			inc cx
-			jmp .line_count_loop
 
 	; COMMANDS
+	;                                   DELETE                              ;
 	.delete:
+		; Adjust the ed line count
+		mov ax,[ed_end_int]
+		sub ax,[ed_start_int] ; difference in the lines
+		inc ax
+		sub [ed_line_count], ax
+
 		; set up registers to shift data left
-		mov bx, ed_end_int
+		; Get the byte of where the left shift will start
+		mov bx, [ed_end_int]
 		inc bx
 		call get_byte_of_line ; CX = byte of start of new line (relative to file buffer)
-		mov [ed_shift_from], cx
+		mov [ed_operation_from], cx
 
-		mov bx, ed_start_int
+		; Get the number of bytes to shift left by
+		mov bx, [ed_start_int]
 		call get_byte_of_line
-		mov ax, ed_start_int
+		mov ax, [ed_operation_from]
 		sub ax, cx
-		mov [ed_shift_by], ax
+		mov [ed_operation_by], ax
+
+		; Perform the shift
+		call shift_data_left
+
+		; Adjust the file metadata byte count
+		mov ax, [file_length]
+		sub ax, [ed_operation_by]
+		mov [file_length], ax
+
+		; Exit
+		call text_newline
+		jmp .main_loop
+
+
+	;                                   LIST                              ;
+	.list:
+		; set up registers to print the data
+		; Get the byte of where the printing will start
+		mov bx, [ed_start_int]
+		call get_byte_of_line ; CX = byte of start of new line (relative to file buffer)
+		mov si, cx
+
+		; Get the number of bytes to print
+		mov bx,[ed_end_int]
+		inc bx
+		call get_byte_of_line
+		sub cx,si
+
+		call text_newline
+		add si, file_buffer
+		call text_print_raw
+		jmp .main_loop
 
 	.quit:
 		popa
-		ret
+		jmp os_start_cli
 
+; This could probably go in disk_?
 shift_data_left:
-	mov si, ed_shift_from
+	; Calculate source pointer
-	mov cx, ed_shift_by
+	mov si, [ed_operation_by]
-	mov di, ed_shift_from
+	add si, file_buffer
-	sub di, cx
-	mov dx, file_length ; STORES THE LENGTH OF THE FILE IN BYTES
-	.shift_left_loop:
-		lodsb
-		stosb
-		cmp al, 0
-		jne .shift_left_loop
-	jmp ed.main_loop
 
-; BX = target line
+	; Calculate destination pointer
+	mov di, si
+	sub di, [ed_operation_by]
+
+	; Loop count
+	mov cx, file_length ; STORES THE LENGTH OF THE FILE IN BYTES
+	sub cx, ed_operation_by
+
+	; Perform the actual left shift
+	rep movsb
+
+	; Override the rest with zeroes
+	mov cx, [ed_operation_by]
+	mov al, 0
+	rep stosb
+
+	ret
+
+ed_error:
+	pusha
+
+	call text_newline
+	mov ah, 0Eh
+	mov al, '?'
+	int 10h
+	call text_newline
+
+	popa
+	ret
+
+; IN: BX = target line
+; OUT: CX = relative byte
+; TODO fix
 get_byte_of_line:
 	push dx
+	push si
+	push ax
+
 	mov si, file_buffer
+
 	xor dx,dx
 	xor cx,cx
+
 	jmp .increment_line_count
 	.line_loop:
+		xor ax,ax
 		lodsb
 		inc cx
+
 		cmp al, 0Ah
 		je .increment_line_count
+
+		jmp .line_loop
 	.increment_line_count:
 		inc dx
 		cmp dx, bx
-		jne .line_loop
+		jl .line_loop
-		inc cx
+		jmp .exit
+	.exit:
+		pop ax
+		pop si
 		pop dx
 		ret
 
+determine_line_count:
+	mov si, file_buffer
+	mov dx, file_length ; STORES THE LENGTH OF THE FILE IN BYTES
+	xor cx,cx
+	.line_count_loop:
+		lodsb
+		cmp al, 0Ah
+		je .increment_line_count
+		dec dx
+		cmp dx, 0
+		jg .line_count_loop
+	mov [ed_line_count], cx
+	ret
+	.increment_line_count:
+		inc cx
+		jmp .line_count_loop
+
 ed_data_start: db "ED IS COOL"
 ed_prompt:	times 40 db 0
-ed_start_int: dw 0
+ed_start_int: dw 1
 ed_end_int: dw 0
 
 ed_line_count: dw 0
 
-ed_shift_from: dw 0
+ed_operation_from: dw 0
-ed_shift_by: dw 0
+ed_operation_by: dw 0
+ed_tmp: dd 0