shell: allow cmds to be shorter than 4 chars

kernel/pgm.asm

@@ -19,30 +19,18 @@
 .equ	PGM_RAMEND	PGM_HANDLE+FS_HANDLE_SIZE
 
 ; Routine suitable to plug into SHELL_CMDHOOK. HL points to the full cmdline.
-; We can mutate it because the shell doesn't do anything with it afterwards.
+; which has been processed to replace the first ' ' with a null char.
 pgmShellHook:
 	call	fsIsOn
 	jr	nz, .noFile
-	; first first space and replace it with zero so that we have something
-	; suitable for fsFindFN.
-	push	hl	; remember beginning
-	ld	a, ' '
-	call	findchar
-	jr	nz, .noarg	; if we have no arg, we want DE to point to the
-				; null char. Also, we have no replacement to
-				; make
-	; replace space with nullchar
-	xor	a
-	ld	(hl), a
-	inc	hl		; make HL point to the beginning of args
-.noarg:
-	ex	de, hl	; DE now points to the beginning of args or to \0 if
-			; no args
-	pop	hl	; HL points to cmdname, properly null-terminated
+	; (HL) is suitable for a direct fsFindFN call
 	call	fsFindFN
 	jr	nz, .noFile
-	; We have a file! Load it and run it.
-	ex	de, hl	; but first, make HL point to unparsed args.
+	; We have a file! Advance HL to args
+	xor	a
+	call	findchar
+	inc	hl		; beginning of args
+	; Alright, ready to run!
 	jp	pgmRun
 .noFile:
 	ld	a, SHELL_ERR_IO_ERROR

kernel/shell.asm

@@ -100,9 +100,23 @@ shellParse:
 	push	hl
 	push	ix
 
+	; Before looking for a suitable command, let's make the cmd line more
+	; usable by replacing the first ' ' with a null char. This way, cmp is
+	; easy to make.
+	push	hl		; --> lvl 1
+	ld	a, ' '
+	call	findchar
+	jr	z, .hasArgs
+	; no arg, (HL) is zero to facilitate processing later, add a second
+	; null next to that one to indicate unambiguously that we have no args.
+	inc	hl
+.hasArgs:
+	xor	a
+	ld	(hl), a
+	pop	hl		; <-- lvl 1, beginning of cmd
+
 	ld	de, shellCmdTbl
-	ld	a, SHELL_CMD_COUNT
-	ld	b, a
+	ld	b, SHELL_CMD_COUNT
 
 .loop:
 	push	de		; we need to keep that table entry around...
@@ -131,13 +145,9 @@ shellParse:
 	call	intoDE		; Jump from the table entry to the cmd addr.
 
 	; advance the HL pointer to the beginning of the args.
-	ld	a, ' '
+	xor	a
 	call	findchar
-	or	a		; end of string? don't increase HL
-	jr	z, .noargs
-	inc	hl		; char after space
-
-.noargs:
+	inc	hl		; beginning of args
 	; Now, let's have DE point to the argspecs
 	ld	a, 4
 	call	addDE

recipes/sms/romasm/glue.asm

@@ -123,7 +123,7 @@ f1PutC:
 	jp	fsPutC
 
 edCmd:
-	.db	"eded", 0b1001, 0, 0
+	.db	"ed", 0, 0, 0b1001, 0, 0
 	push	hl \ pop ix
 	ld	l, (ix)
 	ld	h, (ix+1)