Category : Files from Magazines
Archive   : PJ91.ZIP
Filename : MISC.ASM

title miscellaneous
include asm.inc

public abort_if_cf
public move_file_pointer
public read_from_file
public strcmpi

.data
extw psp

.const
ertx_aborting db 'Aborting',0
ertx_disk_full db 'Disk full',0

.data?
argc dw ?
argv dd ?


.code
extn ms_dos_dialog,get_strerror,set_strerror,perror
extn ms_dos_strerror,malloc


;; abort_if_cf
;
abort_if_cf proc
jnc aic2
call get_strerror
jz aic1
movx si,NULL_POINTER
call perror
aic1: lea ax,ertx_aborting
call set_strerror
call perror
call exit_with_error
aic2: ret
abort_if_cf endp


;; close file
;
; entry BX handle
; exit Cf 0
; uses AX
;
close_file proc
mov ah,3Eh
jmp ms_dos_strerror
close_file endp


;; err disk full
;
; exit Cf 1
; uses AX
;
err_disk_full proc
lea ax,ertx_disk_full
jmp set_strerror
err_disk_full endp


;; exit program
;
exit_program proc
mov ax,4C00h
jmp ms_dos
exit_program endp


;; exit with error
;
exit_with_error proc
mov ax,4C01h
jmp ms_dos
exit_with_error endp


;; get vector
;
; entry AL vector #
; exit DS:SI selected vector
; Zf if null vector
; uses AX
;
get_vector proc
mov ah,0
add ax,ax
add ax,ax
xchg ax,si
xor ax,ax
mov ds,ax
lds si,[si]
mov ax,ds
or ax,si
ret
get_vector endp


;; input file size
;
; entry BX file handle
; exit DX AX size
;
input_file_size proc
pushm cx,di,si
mov ax,4201h ; get current position
movx cx,0
movx dx,0
call ms_dos_strerror
jc ifs1
mov si,dx ; into SI DI
mov di,ax

mov ax,4202h ; move to end of file
movx dx,0
call ms_dos_strerror
jc ifs1

pushm ax,dx
mov ax,4200h ; restore file position
mov cx,si
mov dx,di
call ms_dos_strerror
popm dx,ax

ifs1: popm si,di,cx
ret
input_file_size endp


;; move file pointer
;
; entry BX file handle
; DX AX file position
; exit Cf if error
; uses AX
;
move_file_pointer proc
push cx
mov cx,dx
mov dx,ax
mov ax,4200h
call ms_dos_dialog
pop cx
ret
move_file_pointer endp


;; ms dos
;
ms_dos proc
int 21h
ret
ms_dos endp


;; open input file
;
; entry DS:SI string
; exit AX,BX handle
; Cf if error, error text set
; calls offset_dos_error, ms_dos
;
open_input_file proc
mov ax,3D00h ; (use 3D20 for shared access read)
xchg dx,si
call ms_dos_strerror
xchg dx,si
mov bx,ax
ret
open_input_file endp


;; read command line
;
; exit DS:SI program command line
;
read_command_line proc
mov ds,psp[bp]
mov si,81h
ret
read_command_line endp


;; read environment
;
; exit DS:SI environment
;
read_environment proc
xor si,si
mov ds,psp[bp]
mov ds,[si+2Ch]
ret
read_environment endp


;; read from file
;
; entry BX file handle
; CX byte count
; ES:DI destination
; exit AX number of bytes read
; Cf if error
;
read_from_file proc
push ds
mov ah,3Fh
push es
pop ds
xchg dx,di
call ms_dos_dialog
xchg di,dx
pop ds
ret
read_from_file endp


;; remove
;
; entry DS:SI filename to delete
; exit Cf if error
; uses AX
;
remove proc
mov ah,41h ; delete file
xchg dx,si
call ms_dos_strerror
xchg dx,si
ret
remove endp

even
;; restore most
;
; note never call this routine
;
restore_most proc
popm bp,es,ds,si,di,dx,cx,bx
ret
restore_most endp

even
;; save most
;
; note saves all registers except AX and BP. however, the current
; version also saves BP because the code works out that way.
; the registers are automatically restored. this routine is
; called with a return address as the top of stack.
;
save_most proc ; +16 inner ret adr, +18 outer ret adr
push cx ; +14
push dx ; +12
push di ; +10
push si ; +8
push ds ; +6
push es ; +4
push bp ; +2
lea bp,restore_most ; after execution of inner
push bp ; +0 routine, return to restore_most
mov bp,sp
xchg bx,[bp+16] ; bx above cx
push bx ; -2 setup return to inner routine
mov bx,[bp+16] ; restore original BX and BP
mov bp,[bp+2]
ret
save_most endp


;; set argc argv
;
; exit Cf if no memory
; uses AX,CX,DI,SI,ES,DS
;
set_argc_argv proc
mov cx,256
call malloc
jc saa9 ; if no memory

mov argc[bp],1
mov wptr argv[bp],di
mov wptr argv[bp+2],es

mov ah,30h
call ms_dos
cmp al,3
jb saa10 ; if prior to DOS version 3.x

call read_environment ; skip environment
saa1: call strskp
lodsb
cmp al,NULL_CHAR
jne saa1
lodsw ; (skip 1)

call strcpy ; copy program name which appears
inc di ; after environment

saa2: call read_command_line
saa3: call strskp_white
cmp al,CR_CHAR
je saa7 ; if no more arguments

inc argc[bp]
jmp saa5
saa4: stosb
saa5: lodsb
cmp al,SPACE_CHAR
jbe saa6
cmp al,','
je saa6
cmp al,'~'
jbe saa4

saa6: cmp al,CR_CHAR
mov al,NULL_CHAR
stosb
jne saa3

saa7: inc di ; word align table
and di,-2

lds si,argv[bp] ; get ptr to first argument
mov wptr argv[bp],di ; set pointer list offset
mov cx,argc[bp] ; get list count (cannot==0)

saa8: mov ax,si ; build pointer list
stosw
call strskp
loop saa8
clc
saa9: ret

saa10: mov ax,'C'
stosw
jmp saa2
set_argc_argv endp


;; stosb tmp path
;
; entry ES:DI destination
; exit DI updated
; uses AX
;
stosb_tmp_path proc
mov al,NULL_CHAR
stosb
dec di
ret
stosb_tmp_path endp


;; strcmpi
;
; entry DS:SI string1
; ES:DI string2
; exit Zf if string1==string2
; uses AX
;
strcmpi proc
pushm di,si
sci1: mov ah,es:[di]
lodsb
or ax,ax
jz sci2 ; if same strings
inc di
call tolower
xchg al,ah
call tolower
cmp ah,al
je sci1 ; if strings match so far
sci2: popm si,di
ret
strcmpi endp


;; strcpy
;
; entry DS:SI source ptr
; ES:DI destination ptr
; exit SI updated past NULL
; DI updated, points to NULL
; uses AX
;
strcpy proc
lodsb
stosb
cmp al,NULL_CHAR
jne strcpy
dec di
ret
strcpy endp


;; strcpy limit
;
; entry DS:SI source pointer
; ES:DI destination pointer
; DX destination limit
; exit DI updated to last character in destination
; uses AX
;
strcpy_limit proc
push si
scl1: cmp di,dx
jae scl2 ; if at destination limit

lodsb ; else copy one character
stosb
cmp al,0
jne scl1

dec di
scl2: pop si
ret
strcpy_limit endp


;; strlenz
;
; entry DS:SI string
; exit CX byte count including NULL
; uses AX
;
strlenz proc
push si
movx cx,0
slz1: inc cx
lodsb
cmp al,NULL_CHAR
jne slz1
pop si
ret
strlenz endp


;; strskp
;
; entry DS:SI asciiz string ptr
; exit SI updated past null
; uses AX
;
strskp proc
lodsb
cmp al,NULL_CHAR
jne strskp
ret
strskp endp


;; strskp white
;
; entry DS:SI text ptr
; exit SI updated past spaces and tabs
; AL non-white character
;
strskp_white proc
lodsb
cmp al,SPACE_CHAR
je strskp_white
cmp al,TAB_CHAR
je strskp_white
dec si
ret
strskp_white endp


;; tolower
;
; entry AL char
; exit AL lower cased AL
;
tolower proc
cmp al,'A'
jb tol1
cmp al,'Z'
ja tol1
or al,20h
tol1: ret
tolower endp


public ms_dos,read_command_line,read_environment,set_argc_argv,strcpy
public argv,argc,exit_program,exit_with_error,get_vector,tolower
public close_file,open_input_file,input_file_size,err_disk_full
public remove,save_most,strlenz,strcpy_limit

end