Fixed some bugs with inputs

source/kernel/features/basic.asm

@@ -1950,8 +1950,9 @@ do_input:
 
 .number_var:
 	mov ax, .tmpstring			; Get input from the user
-	mov bx, 6
+	mov bx, 20
 	call keyboard_display_input
+	jc .end
 
 	mov ax, .tmpstring
 	call string_length
@@ -1973,8 +1974,6 @@ do_input:
 	call os_print_newline
 
 	jmp mainloop
-
-
 .string_var:
 	mov ax, 128
 	mul bx
@@ -1987,8 +1986,9 @@ do_input:
 
 	jmp mainloop
 
-
-	.tmpstring	times 6 db 0
+	.tmpstring	times 20 db 0
+.end
+	ret
 
 
 ; -----------------------------------------------------------

source/kernel/features/check.asm

@@ -0,0 +1,29 @@
+check_is_number:
+	cmp al, 48
+	jl .not_number
+	cmp al, 57
+	jg .not_number
+	stc
+	ret
+.not_number:
+	clc
+	ret
+
+check_is_letter:
+	cmp al, 65
+	jl .not_letter
+	cmp al, 122
+	jg .not_letter
+	cmp al, 90
+	jg .maybe_not_letter
+	stc
+	ret
+.maybe_not_letter:
+	cmp al, 97
+	jl .not_letter
+	stc
+	ret
+.not_letter:
+	clc
+	ret
+

source/kernel/features/cli.asm

@@ -11,6 +11,7 @@ os_start_cli:
 	mov ax, user_input
 
 	call keyboard_display_input
+	jc power_reboot
 	jmp os_read_cli
 
 

source/kernel/features/disk.asm

@@ -171,6 +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
 disk_load_file:
    pusha
    call string_length ; cl = string length
@@ -227,11 +228,15 @@ disk_load_file:
 .file_not_found:
    mov si, file_not_found
    call os_print_string
-   jmp .done
+   jmp .done_fail
 .filename_too_long:
    mov si, too_long_filename
    call os_print_string
-   jmp .done
+   jmp .done_fail
+.done_fail:
+	popa
+	stc
+	ret
 .done:
    popa
    ret

source/kernel/features/keyboard.asm

@@ -15,6 +15,7 @@ os_read_input:
 
 ; AX = key pressed
 ; Returns straight away
+; carry flag is set when escape is pressed and data is returned straight away
 keyboard_check_key:
 	xor ax,ax
 	mov ah, 11h			; BIOS call to check for key
@@ -27,11 +28,11 @@ keyboard_check_key:
 ; IN:
 ; AX = output address
 ; BX = max length
-
 keyboard_display_input:
 	pusha
 	mov di, ax
-	mov ax, bx
+	xor ax,ax
+	mov [prompt_length], bx
 
 	.check_key_pressed:
 		call os_read_input
@@ -54,7 +55,9 @@ keyboard_display_input:
 		jmp .check_key_pressed
 
 	.esc_key:
-		call power_reboot
+		stc
+		popa
+		ret
 
 	.enter_key:
 		mov al, 0
@@ -63,7 +66,7 @@ keyboard_display_input:
 		ret ; Return to the parent function (whatever that may be)
 
 	.backspace:
-		cmp bx, 20						; Cannot backspace if the cursor is at the start
+		cmp bx, [prompt_length]						; Cannot backspace if the cursor is at the start
 		jb .move_cursor_back			; then .move_cursor_back
 		jmp .check_key_pressed			; Else check the next key
 
@@ -86,6 +89,7 @@ keyboard_display_input:
 		mov ah, 0Eh
 		int 10h
 		jmp .check_key_pressed
+	.input_length db 0
 
 keyboard_get_cursor_pos:
 	ret

source/kernel/features/strings.asm

@@ -107,7 +107,7 @@ string_join:
 
 ; ------------------------------------------------------------------------
 ; TODO
-; Converts a null terminated string to an integer
+; Converts a string to an integer
 ; IN: SI = string location (max 5 chars, up to '65536')
 ; OUT: AX = number
 string_cast_to_int:
@@ -116,8 +116,12 @@ string_cast_to_int:
 	.loop:
 		xor ax,ax
 		lodsb
-		cmp al, 0
-		je .finish
+
+		cmp al, 30h
+		jl .finish
+		cmp al, 39h
+		jg .finish
+
 		sub al, 30h
 		mov bx, ax
 		mov ax, 10

source/kernel/features/utils.asm

@@ -7,10 +7,12 @@ util_cat:
 	add si, 4   ; Move si to after 'CAT'
 
 	call disk_load_file
+	jc .done ; if file failed to load, just quit
+
 	mov si, file_buffer
 	mov cx, [file_length]
 	call text_print_raw
-
+.done
 	popa
 	ret
 
@@ -34,6 +36,7 @@ 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
 
 	mov si, file_buffer
 
@@ -41,6 +44,7 @@ util_basic:
 	mov si, 0
 	call basic_run_basic
 
+.done
 	popa
 	ret