io Programmo 23/IOPROG_23.ISO/SOFT/ASM/GRDBDL17.ZIP/FILEIO.ASM

Assembly Source File | 1998-10-26 | 4.2 KB | 232 lines

;
; GRDP
;
; Copyright(c) LADsoft
;
; David Lindauer, [e-mail]
;
;
; FILEIO.ASM
;
; Function: Handle File read/wrote commands
;
    ;MASM MODE
    .MODEL SMALL
    .386


include  eprints.inc
include  einput.inc
include  emtrap.inc
include  ebreaks.inc
include  eloader.inc
include  edos.inc
include eexec.inc

    PUBLIC dofileread, dofilewrite, FileLoadErr

    .data
EXEfileFlag    db    0        ;if EXE file, can't write it
writelen    dd    0        ;length to write
writeseg    dw    0        ;segment and
writeofs    dw    0        ; offset to write
newaddr        db    0        ;if @addr used
writeFileName    db    256 DUP (0)    ;name of file to write

    .CODE
;
; read from file
;
doFileRead PROC
    movzx    ax,[lastexe]    ; use state of last load if no params
    xor    al,1
    push    ax
    call    WadeSpace
    jz    PureReadFile    ; branch if reloading same program
    pop    ax        ; else assume anything goes
    push    0
    cmp    byte ptr [si],'@' ; else see if the load-exe-as-com flag set
    jnz    comonly        ; branch if so
    inc    si        ; else anything goes
    pop    ax        ; com only!!!
    push    1
comonly:
    cmp    byte ptr [si],'-' ; see if they want to unload
    jnz    newfile
    pop    ax        ; clear stack
    call    UnLoadProgram    ; yes do it
    clc
    ret
newfile:
    call    WadeSpace    ; if no prog, go read the old one again
    jz    PureReadFile
    call    ParseProgName
PureReadFile:
    pop    ax        ; com/exe flag
    call    LoadProgram    ; call the com/exe loader
    call    FileLoadErr
    ret
doFileRead ENDP
FileLoadErr    PROC
    jc    lperr        ; handle errors
    PRINT_MESSAGE    <10,13,"Size: ">
    mov    eax,FileLen
    call    Printdword
    clc
    ret
lperr:
    PRINT_MESSAGE    <10,13,"Read error">
    clc

    ret
FileLoadErr    ENDP
;
; file write subroutine
;
WriteProgram    PROC
    mov ax,3c00h            ; Open the file
    mov dx,offset writeFileName
    sub    cx,cx
    int 21h
    mov bx,ax
    jc failure

    mov    ecx,[writelen]
    mov    si,[writeseg]
    mov    dx,[writeofs]
    push    ds
wdlp:
    push    ecx
    mov    ds,si
    mov ax,4000h            ; Read the file
    cmp    ecx,8000h
    jc    cursize
    mov cx,8000h
cursize:
    int 21h
    jc failure2
    pop    ecx
    add    si,800h
    sub    ecx,8000h
    jnc    wdlp
    clc
failure2:
    pop    ds
failure:
    pushf
    mov    ax,3e00H
    int    21h
    popf
    ret
WriteProgram ENDP
;
; file write command
;
doFileWrite PROC
    push    si
    mov    [newaddr],0
    mov    si,offset loadfile    ; move the original file name
    mov    di,offset writeFileName
fnl_lp:
    lodsb
    stosb
    or    al,al
    jnz    fnl_lp
    mov    al,[exeflag]             ; set default params
    mov    [EXEfileFlag],al             ; can't write EXE
    mov    eax,[filelen]
    mov    [writelen],eax
    mov    ax,[userbasepsp]
    add    ax,10H
    mov    [writeseg],ax
    mov    [writeofs],0
    pop    si
    call    WadeSpace            ; if no args go to write routine
    jz    dowrite
    cmp    al,'@'                ; see if address
    jnz    gname
    mov    [EXEfileFlag],0            ; yes update params
    mov    [writelen],0
    mov    [writeFileName],0
    mov    [newaddr],1
    inc    si
    call    ReadAddress
    jc    wn_err
    call    defDS                ; get DS
    mov    eax,ebx
    shr    eax,4
    add    edx,eax
    and    ebx,15
    mov    [writeofs],bx
    mov    [writeseg],dx
    test    edx,0FFF00000H
    jnz    wn_err
gname:
    call    WadeSpace             ; now see if there is a name
    jz    dowrite
    cmp    al,','                ; noname, get a length
    jz    getnum
    mov    [EXEfileFlag],0            ; else get name
    mov    di,offset writeFileName
fclp:
    mov    byte ptr [di],0
    lodsb
    cmp    al,13
    jz    dowrite
    cmp    al,' '
    jz    getnum
    cmp    al,','
    jz    getnum
    stosb
    jmp    fclp
getnum:
    call    WadeSpace             ; now see if len
    jz    dowrite
    mov    [EXEfileFlag],0
    call    ReadNumber
    jc    wn_err
    mov    ebx,eax
    call    WadeSpace
    jnz    wn_err
    mov    [WriteLen],ebx
dowrite:
    test    [EXEfileFlag],0FFH        ; all params got, see if exe
    jnz    noexewrite            ; yes, can't write
    test    [writelen],0FFFFFFFFH        ; see if anything
    jz    wn_err                ; no,err
    movzx    eax,[writeseg]
    shl    eax,4
    add    eax,[writelen]
    add    eax,0FH
    test    eax,0FFF00000H            ; 1 MB limit
    jnz    wn_err
    call    WriteProgram            ; write prog
    jnc    nowriterr
    PRINT_MESSAGE    <10,13,"Write error">
nowriterr:
    test    [newaddr],1            ; update params
    jnz    nochange
    mov    eax,[writelen]
    mov    [FileLen],eax
    mov    al,[EXEfileFlag]
    mov    [exeflag],al
    mov    si,offset writeFileName
    mov    di,offset loadfile
fnl_lp1:
    lodsb
    stosb
    or    al,al
    jnz    fnl_lp1

nochange:
    clc
    ret
noexewrite:
    PRINT_MESSAGE    <10,13,"Can't write back an EXE file">
    clc
    ret
wn_err:
    stc
    ret
doFileWrite ENDP
end