The Unsorted BBS Collection/thegreatunsorted.tar/thegreatunsorted/programming/misc_programming/combine.asm

Assembly Source File | 1996-10-19 | 11KB | 458 lines

; COMBINE.ASM    Interrupt List combiner
;        by Ralf Brown
;        last edit: 19oct96

        NAME    COMBINE
        TITLE    Combine Interrupt List sections

; declare all the segments in the order in which they are to appear in the
; executable
CODE    SEGMENT 'CODE'
CODE    ENDS
STACKSEG SEGMENT PUBLIC WORD 'STACK'
STACKSEG ENDS
BUFFERSEG SEGMENT PUBLIC WORD 'DATA'
BUFFERSEG ENDS
;
DGROUP    GROUP    CODE,STACKSEG,BUFFERSEG

;;------------------------------------------------------------------------

FFBLK struc
  ff_reserved    db 15h dup (?)
  ff_attrib    db ?
  ff_ftime    dw ?
  ff_fdate    dw ?
  ff_fsize    dd ?
  ff_fname    db 13 dup (?)
FFBLK ends

;;------------------------------------------------------------------------

CODE    SEGMENT 'CODE'
    ORG    100h            ; this is a .COM file
    ASSUME    CS:DGROUP,DS:DGROUP,ES:DGROUP,SS:DGROUP

combine:
    jmp    near ptr main

banner        db    13,"COMBINE v2.00",9,"Ralf Brown 1996",13,10,"$",26
usage_msg    db    "Usage:",9,"COMBINE [options] dest-dir",13,10
        db    9,"where {dest-dir} is the directory in which to place",13,10
        db    9,"  the combined list ('.' for the current directory)",13,10
        db    10
        db    9,"options:",13,10
        db    9,9,"-d",9,"delete sections after copying",13,10
        db    10
        db    "All sections of the interrupt list must be in the current directory."
        db    "$"

bad_dos_msg    db    "Need DOS 2.0+$"
bad_drive_msg    db    "Invalid destination drive$"
no_mem_msg    db    "Insufficient memory$"
no_files_msg    db    "No section files found!$"
readerr_msg    db    "Read Error$"
writeerr_msg    db    "Write Error$"
diskfull_msg    db    "Disk full? while writing$"
no_disk_msg    db    "Out of space on destination drive",13,10,"$"
retry_msg    db    "Try again with -d to delete while copying$"

cant_create_msg db    "Check directory name -- unable to create "
combined_file    db    "INTERRUP.LST",0,"$"
section_file    db    "INTERRUP.A",0,"$"
section_letter equ section_file+9
missing_msg    db    "unavailable (skipped)"
crlf        db    13,10,"$"
section_heading db    "Interrupt List, part "
section_hdr_len equ $-section_heading
complete_msg    db    "Done.$"

;
; flags affecting operation
;
del_after_copy    db    0

;
; data needed while processing
;
filehandle    equ    di        ; output file's handle
numsections    db    26
dest_drive    db    0
nondefault_dest    db    0
ftime        dw    0
fdate        dw    0
filesize_lo    dw    0
filesize_hi    equ    bp

; (since we don't use disk_buffer until after FindFirst is no longer needed,
; save memory by overlaying the two)
FindFirst    equ    DGROUP:disk_buffer

;;------------------------------------------------------------------------

write_string:
    mov    ah,9
    int    21h
    ret

;;------------------------------------------------------------------------

skip_whitespace:
    lodsb
    cmp    al,' '
    je    skip_whitespace
    cmp    al,9
    je    skip_whitespace
    dec    si            ; unget the last character
    ; set ZF to indicate whether we got to end of cmdline
    cmp    al,0Dh
    ret

;;------------------------------------------------------------------------

get_destination_file:
    mov    bx,si            ; remember start of destination name
get_dest_file_loop:
    lodsb
    cmp    al,' '
    je    got_dest_end
    cmp    al,9
    je    got_dest_end
    cmp    al,0Dh
    jne    get_dest_file_loop
got_dest_end:
    dec    si            ; unget last character
    mov    di,si
    mov    al,[si-1]        ; check end of path -- is it terminated
    cmp    al,'\'            ;   by a slash or backslash?
    je    dest_has_slash
    cmp    al,'/'
    je    dest_has_slash
    cmp    al,':'
    je    dest_has_slash
    mov    al,'\'
    stosb
dest_has_slash:
    mov    si,offset combined_file
dest_copy_loop:
    lodsb
    stosb
    cmp    al,0
    jne    dest_copy_loop
    ; OK, now open the destination file
    ; (BX is still pointing at start of pathname)
    cmp    byte ptr [bx+1],':'
    jne    got_dest_drive
    mov    al,[bx]
    and    al,0DFh            ; force to uppercase
    sub    al,'A'
    jb    got_dest_drive
    cmp    al,dest_drive
    je    got_dest_drive
    mov    dest_drive,al
    mov    nondefault_dest,al
got_dest_drive:
    mov    ah,3Ch            ; create the output file
    xor    cx,cx            ; no special file attributes
    mov    dx,bx
    int    21h
    mov    dx,offset cant_create_msg
    jc    exit_with_err_2
    mov    filehandle,ax
    ret

;;------------------------------------------------------------------------

check_total_size:
    mov    byte ptr section_letter,'A'-1
    mov    ah,1Ah            ; set DTA
    mov    dx,offset FindFirst
    int    21h
    xor    si,si            ; keep track of # of sections found
check_size_loop:
    inc    byte ptr section_letter
    cmp    byte ptr section_letter,'Z'
    ja    short get_free_space
    mov    ah,4Eh            ; find first
    mov    cx,001Fh        ; ...regardless of attribute
    mov    dx,offset section_file
    int    21h
    jc    check_size_loop
    inc    si            ; another section found
    mov    ax,FindFirst.ff_ftime
    mov    ftime,ax
    mov    ax,FindFirst.ff_fdate
    mov    fdate,ax
    mov    ax,word ptr FindFirst.ff_fsize
    mov    dx,word ptr FindFirst.ff_fsize+2
    cmp    del_after_copy,0
    je    count_full_size
    cmp    nondefault_dest,0
    jnz    count_full_size
    cmp    dx,filesize_hi
    jb    check_size_loop
    ja    check_size_bigger
    cmp    ax,filesize_lo
    jbe    check_size_loop
check_size_bigger:
    mov    filesize_lo,ax
    mov    filesize_hi,dx
    jmp    check_size_loop

count_full_size:
    add    filesize_lo,ax
    adc    filesize_hi,dx
    jmp    check_size_loop

get_free_space:
    test    si,si            ; check number of sections found
    mov    dx,offset no_files_msg
    jz    short exit_with_err_2
    mov    dl,dest_drive
    inc    dx
    mov    ah,36h            ; get free disk space
    int    21h
    cmp    ax,0FFFFh
    jne    got_free_space
    mov    dx,offset bad_drive_msg
exit_with_err_2:
    jmp    near ptr exit_with_errmsg
got_free_space:
    mul    cx            ; DX:AX <- AX*CX
    mov    cx,dx            ; store high half of intermediate
    mul    bx            ; DX:AX <- low(AX*CX)*BX
    xchg    ax,bx            ; store low half of second interm.
    xchg    cx,dx            ; store high half of second interm.
    mul    dx            ; DX:AX <- high(AX*CX)*BX
    xchg    ax,bx            ; DX:BX:0000h + CX:AX = result
    add    bx,cx
    adc    dx,0            ; DX:BX:AX = AX*BX*CX = free space
    jnz    plenty_free_space    ; >4G free?
    sub    ax,filesize_lo
    sbb    bx,filesize_hi
    jnb    plenty_free_space
not_enough_space:
    mov    dx,offset no_disk_msg
    call    write_string
    cmp    nondefault_dest,0
    jnz    size_check_failed
    cmp    del_after_copy,0
    jne    size_check_failed
    mov    dx,offset retry_msg
    call    write_string
size_check_failed:
    mov    al,2
    jmp    exit
plenty_free_space:
    ret

;;------------------------------------------------------------------------

check_section_header:
    push    si
    push    di
    mov    si,offset DGROUP:disk_buffer
    mov    di,offset section_heading
    mov    cx,section_hdr_len
    or    cx,cx
    rep    cmpsb
    jnz    not_section_heading
scan_curr_section:
    lodsb
    cmp    al,' '            ; scan for the " of "
    jne    scan_curr_section
    add    si,3            ; skip "of "
    xor    cl,cl
num_sections_loop:
    lodsb
    sub    al,'0'
    jb    num_sections_done
    cmp    al,9
    ja    num_sections_done
    mov    ch,al
    mov    al,10
    mul    cl
    mov    cl,al
    add    cl,ch
    jmp    num_sections_loop
num_sections_done:
    mov    numsections,cl
got_num_sections:
not_section_heading:
    pop    di
    pop    si
    ret

;;------------------------------------------------------------------------

; in:    SI = file handle for current section
copy_section:
    mov    ax,4201h
    mov    bx,filehandle
    xor    cx,cx
    xor    dx,dx
    int    21h            ; get current file position (== size)
    mov    filesize_lo,ax
    mov    filesize_hi,dx
copy_section_loop:
    mov    ah,3Fh
    mov    bx,si
    mov    cx,disk_buffer_end - disk_buffer
    mov    dx,offset DGROUP:disk_buffer
    int    21h
    jc    copy_read_error
    mov    cx,ax            ; write same number of bytes read
    mov    ah,40h
    mov    bx,filehandle
;;    mov    dx,offset DGROUP:disk_buffer
    int    21h
    mov    dx,offset writeerr_msg
    jc    copy_error
    mov    dx,offset diskfull_msg
    cmp    ax,cx
    jb    copy_error
    ; check for section header at start of buffer, and extract number
    ; of sections from it
    push    cx
    call    check_section_header
    pop    ax
    cmp    ax,disk_buffer_end - disk_buffer ; continue until only partial
    je    copy_section_loop         ;   buffer read (EOF hit)
    ret

copy_read_error:
    mov    dx,offset readerr_msg
copy_error:
    ; truncate output to size before section was started
    push    dx            ; store error message
    mov    ax,4200h
    mov    bx,filehandle
    mov    cx,filesize_hi
    mov    dx,filesize_lo
    int    21h
    mov    ah,40h
    xor    cx,cx            ; write zero bytes to truncate
    int    21h
    pop    dx            ; get back error message
    ;; fall through to exit_with_errmsg ;;

;;------------------------------------------------------------------------

exit_with_errmsg:
    call    write_string
    ; exit with errorlevel 1
    mov    al,01h
    jmp    near ptr exit

main:
    ASSUME    CS:DGROUP, DS:DGROUP, ES:DGROUP, SS:DGROUP
    mov    dx,offset banner
    call    write_string
    ; relocate the stack
    mov    sp,offset DGROUP:stackbot
    ; ensure that we have enough memory
    mov    ax,cs
    add    ax,1000h        ; require 64K memory
    cmp    ax,ds:[0002h]        ; is end of mem at least 64K above CS?
    mov    dx,offset no_mem_msg
    ja    exit_with_errmsg
    mov    si,81h            ; point at start of cmdline
    mov    bl,[si-1]        ; get length of cmdline
    mov    bh,0
    mov    byte ptr [bx+si],0Dh    ; ensure cmdline properly terminated
    cld
    call    skip_whitespace
    mov    dx,offset usage_msg
    jz    exit_with_errmsg
get_cmdline_switches:
    call    skip_whitespace
    jz    not_a_switch
    cmp    al,'-'            ; is it a switch?
    jne    not_a_switch
    lodsb                ; get the switch character
    lodsb                ; get the switch itself
    and    al,0DFh            ; force to uppercase
    cmp    al,'D'
;;    mov    dx,offset usage_msg
    jne    exit_with_errmsg
    mov    del_after_copy,1
    jmp    get_cmdline_switches
not_a_switch:
    mov    ah,19h            ; get default drive
    int    21h
    mov    dest_drive,al
    mov    ah,30h
    int    21h
    cmp    al,2
    mov    dx,offset bad_dos_msg
    jb    exit_with_errmsg
    call    get_destination_file
    xor    filesize_hi,filesize_hi
    call    check_total_size
    ;
    ; OK, all the preliminaries are done now, so go concatenate the
    ; sections of the interrupt list
    ;
    mov    al,'A'-1
concat_loop:
    inc    ax
    mov    section_letter,al
    sub    al,'A'-1
    cmp    al,numsections
    ja    concat_done
    mov    dx,offset section_file
    call    write_string
    mov    ax,3D00h
    int    21h
    mov    dx,offset missing_msg
    jc    concat_loop_end
    mov    si,ax
    call    copy_section
    mov    ah,3Eh
    mov    bx,si            ; BX <- section file's handle
    int    21h            ; close the file
    cmp    del_after_copy,0
    je    concat_no_del
    mov    ah,41h
    mov    dx,offset section_file
    int    21h
concat_no_del:
    mov    dx,offset crlf
concat_loop_end:
    call    write_string
    mov    al,section_letter
    jmp    concat_loop

concat_done:
    mov    dx,offset complete_msg
    call    write_string
    mov    al,00h            ; successful completion
exit:
    push    ax
    mov    dx,offset crlf
    call    write_string
    mov    bx,filehandle        ; set timestamp of combined file to
    mov    cx,ftime        ;   be that of the last of the sections
    mov    dx,fdate
    mov    ax,5701h        ; (set file time & date)
    int    21h
    mov    ah,3Eh            ; close the destination file
    int    21h
    pop    ax
    mov    ah,4Ch
    int    21h

CODE ENDS

STACKSEG SEGMENT PUBLIC WORD 'STACK'
stacktop dw    160 dup (?)
stackbot label byte
STACKSEG ENDS

BUFFERSEG SEGMENT PUBLIC WORD 'DATA'
disk_buffer db 62*1024 dup (?)
disk_buffer_end label byte
BUFFERSEG ENDS

    END combine