Category : Assembly Language Source Code
Archive   : STDLIB_A.ZIP
Filename : STRDEL2.ASM

stdlib segment para public 'slcode'
assume cs:stdlib
;
extrn sl_malloc:far
;
; strdel2- deletes characters from a string.
;
; inputs:
;
; ES:DI- Points at the string to delete characters from.
;
; CX- Index into source string (ES:DI) to begin deletion.
;
; AX- Number of characters to delete.
;
; outputs:
;
; ES:DI- Points at new string on stack which is the image of the
; source string minus the specified characters.
;
; Carry=1 if memory allocation error, 0 if sufficient memory for the
; new string.
;
;
public sl_strdel2
;
;
sl_strdel2 proc far
push es
push di
push si
push ds
push ax
push bx
push cx
mov bx, ax ;Save length
;
; Compute the length of the source string:
;
push es
push di
push cx
mov cx, 0ffffh
mov al, 0
repne scasb
neg cx
sub cx, bx ;Compute length of new str.
jnc DoAlloc ;Too much to delete?
pop cx ;Use insertion point as
push cx ; the length.
;
DoAlloc: call sl_malloc
jnc GoodAlloc
add sp, 6
pop cx
pop bx
pop ax
pop ds
pop si
pop di
pop es
ret
;
GoodAlloc: pop cx
pop si
pop ds
push es ;Save ptr to new string.
push di
Cpy1: lodsb
stosb
cmp al, 0
loopne Cpy1
jz DelDone
Skp1: mov cx, bx ;Get # chars to delete
Skp2: lodsb
cmp al, 0
loopne Skp2
jz DelDone
Cpy2: lodsb
stosb
cmp al, 0
jnz Cpy2
;
DelDone: mov byte ptr es:[di], 0
pop di
pop es
pop cx
pop bx
pop ax
pop ds
pop si
add sp, 4 ;Don't restore es:di
ret
sl_strdel2 endp
;
;
stdlib ends
end