Clean of Assembly Source series

This is the past DOS era of the compilation of source code, although has passed, but for the study of the assembly is still helpful, assembly language is just a basic programmer language, most people can grasp, not necessarily in-depth research.

Name Clean
Page 55,132
Title ' Clean---Filter text file '
;
; Clean---A utility to filter text files.
; This program removes the all control codes except
; For line feeds, carriage returns, and form
; Feeds, strips off the high bit of all characters,
;　and Expands tabs. Can is used to make a WordStar
; File acceptable for other screens or line editors,
; and vice versa.
;
; Version 1.1 Dec blocking/deblocking
; Version 1.0 Nov 83
;
; Copyright (c) 1983 by Ray Duncan
CR Equ 0DH; ASCII Carriage return
LF equ 0ah; ASCII line Feed
FF equ 0ch; ASCII Form Feed
EOF Equ 01ah; End of file marker
tab EQU 09h; ASCII Tab character
command equ 80h; buffer for command tail
Blksize equ 1024; blocking/deblocking size
CSEG segment para public ' CODE '
Assume Cs:cseg,ds:data,es:data,ss:stack
Clean proc Far, entry point from Pc-dos
Push DS; save ds:0000 for final
XOR Ax,ax; return to Pc-dos
Push AX
mov ax,data; make our data segment
MOV es,ax; addressable via ES Register
Call infile, get path and file spec.
; For input file
MOV ax,es set ds=es for remainder
MOV ds,ax;
Jnc Clean1 Jump, got acceptable name
mov dx,offset msg4; missing or illegal filespec,
JMP clean9;p rint error message and exit.
Clean1:call outfile, set up output file name
Call Open_input. Now try to open input file
JNC clean2; jump,opened input OK
mov dx,offset MSG1; Open of input file failed,
JMP clean9;p rint error msg and exit.
Clean2:
Call Open_output, try to open output file.
Jnc clean25; jump,opened OK
mov dx,offset msg2; Open of output file failed,
JMP clean9;p rint error message and exit.
CLEAN25:; set up buffers
Call Init_buffs
Call sign_on;p rint ident and file names
; files successfully opened,
CLEAN3:; now filter the file.
Call Get_char, read 1 character from input.
And al,07fh strip off the high bit
CMP al,20h is it's it a control code?
Jae Clean4 no,write it to new file
; Yes it control code,
CMP Al,eof's It end of file marker?
Je clean6 yes,jump to close files.
CMP Al,tab is it a tab command?
JZ Clean5 yes,jump to special processing.
CMP AL,CR; If control code other than
Je clean35 tab or end-of-file mark, throw
CMP al,ff; it away unless it is a
Je clean35 form feed, carriage return,
CMP Al,lf or line feeds.
Jne CLEAN3
Clean35:; If It is one of the those three,
MOV column,0; incidentally initialize
JMP clean45 column count for tab processor.
CLEAN4:; count alphanumeric chars. Sent.
INC column
Clean45:; write this character to
Call Put_char output file,
Jnc CLEAN3 If CY not set, write is
; ok so go get next char.
Clean47:
Call Close_input if CY set, disk are full
Call Close_output. So close files and exit
MOV dx,offset MSG5 with error message.
JMP Clean9
CLEAN5:;p rocess Tab character
mov ax,column; let dx:ax=column count
Cwd
mov cx,8;d ivide it by eight ...
Idiv CX
Sub cx,dx; remainder is in DX.
Add column,cx Update column pointer.
Clean55:; 8 minus the remainder
Push CX; gives us the number of
mov al,20h; spaces to send out to
Call Put_char, move to the next tab position
Pop cx; restore space count
JC Clean47 Jump If disk is full
Loop Clean55
JMP short clean3. Get Next character
CLEAN6:; End of file detected,
Call Put_char; write End-of-file marker,
JC Clean47; Jump if disk is full
Call Flush_buffs, write remaining data to disk
JC Clean47 If CY Set,disk is full
; otherwise file was written ok
Call Close_input, close input and output
Call Close_output, files.
mov dx,offset msg3; addr of Success message,
Clean9:;p rint and return
mov ah,9; control to Pc-dos
int 21h
Ret
Clean ENDP
infile proc near;p rocess name of input file
;D s:si <-addr command line
MOV si,offset command
; es:di <-Addr filespec Buffer
MOV Di,offset input_name
Cld
LODSB any command line present?
or Al,al return error status if not.
JZ infile4
Infile1: Scan over leading blanks
LODSB to file name
CMP AL,CR If we hit carriage return
JZ infile4, filename is missing.
CMP al,20h is this a blank?
JZ Infile1 If so keep scanning.
Infile2:; found the name,
STOSB move last char. to output
, file name buffer.
LODSB check next character, found
CMP AL,CR carriage return yet?
Je infile3 yes,exit with success code
CMP al,20h is this a blank?
Jne Infile2 if not keep moving chars.
Infile3:; Exit with carry =0
CLC; For Success Flag
Ret
Infile4:; Exit with carry =1
STC; for error flag
Ret
InFile ENDP
outfile proc near; set up path and file
CLD; name for output file.
mov cx,64 length to move
mov si,offset input_name; source addr
mov di,offset output_name;d est addr
Rep MOVSB; Transfer the string
MOV Di,offset output_name
Outfile1:; scan string looking for
mov Al,[di]; "." Marking start of extension
or Al,al or zero byte marking name end.
JZ Outfile2 if either is found,jump.
CMP al, '. '
Je outfile2 bump string pointer, loop
Inc di; If neither '. ' or zero found.
JMP Outfile1
Outfile2: Found zero or '. ', force the
; Extension of the output file
; to '. CLN '
MOV Si,offset outfile_ext
MOV cx,5
Rep MOVSB
RET; back to caller
OutFile ENDP
Open_input proc near; open input file
;D s:dx=addr filename
MOV Dx,offset input_name
MOV al,0; Al=0 for Read Only
mov ah,3dh; function 3dh=open
int 21h; handle returned in AX,
MOV input_handle,ax; save it for later.
RET; CY is set if error
Open_input ENDP
Open_output proc near; open output file
;D s:dx=addr filename
MOV Dx,offset output_name
MOV al,1; Al=1 for write only
mov ah,3ch; function 3ch=make or
int 21h; Truncate existing file
; handle returned in AX
MOV Output_handle,ax;save it for later.
RET; return cy=true if error
Open_output ENDP
Close_input proc near; close input file
MOV bx,input_handle; Bx=handle
MOV Ah,3eh
int 21h
Ret
Close_input ENDP
Close_output proc near; close output file
MOV bx,output_handle; Bx=handle
MOV Ah,3eh
int 21h
Ret
Close_output ENDP
Get_char proc near; get one character from input buffer
MOV bx,input_ptr
CMP bx,blksize
Jne get_char1
Call Read_block
MOV bx,0
GET_CHAR1:
MOV AL,[INPUT_BUFFER+BX]
Inc BX
MOV input_ptr,bx
Ret
Get_char ENDP
PUT_CHAR proc near;p ut one character into output buffer
MOV bx,output_ptr
mov [output_buffer+bx],al
Inc BX
MOV output_ptr,bx
CMP bx,blksize, buffer full yet?
Jne put_char1; no,jump
Call Write_block; yes,write
RET; return CY as status code
PUT_CHAR1:
CLC; return CY clear for OK status
Ret
Put_char ENDP
Read_block proc Near
MOV bx,input_handle; read a-block of input
MOV cx,blksize
MOV Dx,offset input_buffer
MOV ah,3fh
int 21h
Jnc read_block1 Jump if no error status
MOV ax,0; Simulate a zero length read if error
Read_block1:
CMP Ax,blksize is full buffer read in?
Je read_block2; yes,jump
mov bx,ax no, store end-of-file mark
mov byte ptr [input_buffer+bx],eof
Read_block2:
XOR Ax,ax; Initialize input buffer pointer
MOV Input_ptr,ax
Ret
Read_block ENDP
Write_block proc near; write blocked output (blksize bytes)
MOV Dx,offset output_buffer
MOV cx,blksize
MOV Bx,output_handle
MOV ah,40h
int 21h
XOR BX,BX initialize pointer to blocking buffer
MOV output_ptr,bx
CMP Ax,blksize was correct length written?
Jne Write_block1 No,disk must is full
CLC; Yes,return cy=0 indicating all OK
Ret
Write_block1:;d ISK is full, return CY =1
STC; as error code
Ret
Write_block ENDP
init_buffs proc Near
Call Read_block Read 1st block of input
XOR Ax,ax; initialize pointer to output
mov output_ptr,ax; output blocking buffer
Ret
Init_buffs ENDP
flush_buffs proc near; write any data in output buffer to disk
MOV cx,output_ptr
or CX,CX
JZ flush_buffs1 Jump,buffer is empty
MOV Bx,output_handle
MOV Dx,offset output_buffer
MOV ah,40h
int 21h
CMP Ax,output_ptr was write successful?
JNZ FLUSH_BUFFS2; no,jump
FLUSH_BUFFS1:
CLC; Yes,return cy=0 for
a ret; a success flag.
FLUSH_BUFFS2:;d ISK is full so write failed,
STC; return Cy=1 as Error flag
Ret
Flush_buffs ENDP
sign_on proc near;p rint sign-on message
mov dx,offset msg6, title ...
MOV ah,9
int 21h
MOV dx,offset msg7 input file:
MOV ah,9
int 21h
MOV Dx,offset input_name
Call Pasciiz
mov dx,offset msg8; output file:
MOV ah,9
int 21h
MOV Dx,offset output_name
Call Pasciiz
MOV Dx,offset MSG9
MOV ah,9
int 21h
Ret
sign_on ENDP
Pasciiz proc near; call Dx=offset of Asciiz string
MOV bx,dx which'll is printed on standard output
PASCIIZ1:
MOV DL,[BX]
or DL,DL
JZ pasciiz9
CMP dl, ' A '
JB PASCIIZ2
CMP dl, ' Z '
JA pasciiz2
or dl,20h
PASCIIZ2:
MOV ah,2
int 21h
Inc BX
JMP PASCIIZ1
Pasciiz9:
Ret
Pasciiz ENDP
Cseg ends
Data segment para public ' data '
Input_name db DUP (0); buffer for input filespec
Output_name db DUP (0); buffer for output filespec
Input_handle DW 0; token returned by PCDOs
Output_handle DW 0; token returned by PCDOs
Input_ptr DW 0;p ointer to input blocking buffer
Output_ptr DW 0;p ointer to output blocking buffer
Outfile_ext db '. CLN ', 0; extension for filtered file
Column DW 0; column count for tab processing
MSG1 DB CR,LF
DB ' cannot find input file. '
DB Cr,lf, ' $ '
MSG2 DB CR,LF
DB ' Failed to open output file. '
DB Cr,lf, ' $ '
MSG3 DB CR,LF
DB ' File processing completed '
DB Cr,lf, ' $ '
MSG4 DB CR,LF
DB ' Missing file name. '
DB Cr,lf, ' $ '
MSG5 DB CR,LF
DB ' Disk is full. '
DB Cr,lf, ' $ '
MSG6 DB CR,LF
DB ' Clean Word processing File '
DB CR,LF
DB ' Copyright (c) 1983 Laboratory Microsystems Inc. '
DB Cr,lf, ' $ '
Msg7 db cr,lf, ' Input file: $ '
MSG8 db cr,lf, ' Output file: $ '
MSG9 db cr,lf, ' $ '
Input_buffer db blksize dup (?) ; Buffer for deblocking of data
; from input file
Output_buffer db blksize dup (?) ; Buffer for blocking of data
; Sent to output file
Data ends
Stack segment para stack ' stack '
DB DUP (?)
Stack ends
End Clean