Cream of the Crop 1/Cream of the Crop 1.iso/UTILITY/CMDED2E6.ARJ/EDIT.ASM

Assembly Source File | 1992-06-30 | 30KB | 1,163 lines

; EDIT.ASM
; (c) 1989, 1990 Ashok P. Nadkarni
;
; This module contains the line editing functions of CMDEDIT.
; Macro disable toggle added by dfa,  December 1990.
; Ability to switch ESC to filename completion added by dfa, May 1991.
; Twiddle key and filename display added by wd.
; Disable backslash appending to directory name added by dfa,  June 1992.
; Tab completion cycling added by wd and dfa,  June 1992.

    PUBLIC    get_kbd_line
    PUBLIC    auto_recall
    PUBLIC    expand_fnkey
    PUBLIC    BKS_key_function    ;Added by wd
    PUBLIC    ESC_key_function    ;Added by dfa
    PUBLIC    TAB_key_function    ;Added by dfa
    PUBLIC    backslash_char        ;Added by dfa & wd
    PUBLIC    getkey_funcnum        ;Added by wd

    INCLUDE common.inc
    INCLUDE buffers.inc        ;Added by wd
    INCLUDE ascii.inc
    INCLUDE    BIOS.INC
    INCLUDE    DOS.INC
    INCLUDE    GENERAL.INC


CSEG    SEGMENT    PARA PUBLIC 'CODE'
CSEG    ENDS

DGROUP    GROUP    CSEG

    ASSUME    CS:DGROUP, DS:DGROUP, SS:DGROUP, ES:DGROUP

CSEG    SEGMENT    PARA PUBLIC 'CODE'

    EXTRN    linebuf:BYTE
    EXTRN    lastchar:WORD
    EXTRN    caller_cursor:WORD
    EXTRN    dot:WORD
    EXTRN    edit_mode:BYTE
    EXTRN    omode_cursor:WORD
    EXTRN    disable_macro:BYTE    ;added by dfa
    EXTRN    initial_currow:BYTE    ;added by wd
    EXTRN    sym_stk:WORD
    EXTRN    LINEBUF_END:ABS

; These 7 lines added by wd
FFBLK_SAVE_SIZE equ    30
ffblk_save    db    FFBLK_SAVE_SIZE dup (?)

CycleFlags    db    0        ;bit 0 == 1 if cmd is cycle_complete
                    ;bit 1 == 1 if last cmd was ''
fnameptr    dw    0        ;fname location in linebuf
olddot        dw    0        ;Remember where dot was

tempchar db    ?            ;Temporary storage
auto_recall    db    0        ;By default no auto recall
auto_recall_on    db    ?        ;1 if auto-recall in effect,
;                     else 0
continue_recall db    ?        ;auto-recall state variable
backslash_char    db    '\'        ;added by dfa & wd
fnkey_tab    db    'S','F',0    ;Used to look for function key
;                     definitions.
fnkey_exec_char db    '@'        ;If the last character a fn key
;                     definition is this, the key is
;                     executed immediately
getkey_funcnum    db    8        ;what function to use for getkey

; Must be IDENTICAL to the string in CMDCONF.C including the
; terminating '\0' byte. This must be followed immediately by ctrl_key_defs.
cmdedit_keymap_id db    'CMDEDIT key map',0
; ctrl_key_redefs is used to allow the cmdconf program to remap the control
; keys. Each entry corresponds to a control key. It must immediately follow
; cmdedit_keymap_id.
ctrl_key_redefs LABEL WORD
x    =    0
    REPT    32                ;32 control keys
    DW    x
x    =    x + 1
    ENDM


    EXTRN    disp_line:PROC
    EXTRN    hist_back:PROC
    EXTRN    hist_fwd:PROC
    EXTRN    hist_bck_match:PROC
    EXTRN    hist_fwd_match:PROC
    EXTRN    remember:PROC
    EXTRN    execute_auto_recall:PROC
    EXTRN    insert_at_dot:PROC
    EXTRN    erase_to_dot:PROC
    EXTRN    isalphnum:PROC
    EXTRN    set_disp_marks:PROC
    EXTRN    bell:PROC
    EXTRN    line_to_scr:PROC
    EXTRN    isspace:PROC
    EXTRN    xlate_lower:PROC
    EXTRN    expand_var:PROC
    EXTRN    ismacsym:PROC
    EXTRN    get_symbol:PROC
    EXTRN    tolower:PROC        ;added by wd
    EXTRN    disp_prompt:PROC    ;added by wd
    EXTRN    get_curpos:PROC     ;added by wd
    EXTRN    output_newline:PROC    ;added by wd

;number of command keys
NUM_CMD_KEYS    EQU    (cmd_key_jumps-cmd_key_table)/2

;+
; FUNCTION : get_kbd_line
;
;    Gets a line from the user and stores it in linebuf. The length
;    of the line is stored in global linelen. The name is a misnomer
;    because the line is from standard input, not necessarily from
;    the keyboard.
;
; Parameters:
;    None.
;
; Returns:
;    Nothing.
; Register(s) destroyed:
;-

get_kbd_line    proc    near
    @save    si,di
    mov    al,auto_recall
    mov    auto_recall_on,al    ;Indicate if auto-recall is enabled
    mov    continue_recall,1    ;Init auto-recall memory

; Main editing loop
@get_kbd_line_10:
    mov    al,continue_recall
    and    auto_recall_on,al    ;Indicate if we should keep
;                     auto-recalling
    mov    continue_recall,0    ;Reset the flag. It will be set
;                     for the default actions keys.
    call    near ptr disp_line    ;Show current line
    shl    CycleFlags,1        ;shift the cycle_complete flag (wd)
    mov    ah,getkey_funcnum    ;might be a raw keystroke (wd)
    call    near ptr getkey        ;get next key from the user
    and    CycleFlags,6        ;assume this cmd isn't a cycle_complete
;    mov    si,ax            ;si holds the character (not used--wd)
    cmp    ax,32            ;Control character ?
    jge    @get_kbd_line_15    ;No, then check if fn key
    mov    di,ax            ;DI used to calculate
    add    di,di            ;  offset into table
    mov    ax,ctrl_key_redefs[di]    ;Mapping of key
;    mov    si,ax            ;(not used -- wd)
    cmp    ax,32            ;Control char ?
    jge    @get_kbd_line_15    ;No, then check if fn key
    mov    di,ax            ;DI used to calculate
    add    di,di            ;  offset into table
    jmp    ctrl_key_table[di]    ;Branch according to control char
@get_kbd_line_15:            ;Check if function key
    cmp    ax,256+59        ;>= F1 ?
    jb    @get_kbd_line_20    ;No, then check next table
    cmp    ax,256+68        ;<= F10
    jg    @get_kbd_line_20    ;Not fn key
    jmp    @fn_key            ;Handle the function key
@get_kbd_line_20:
    cmp    ax,256+84        ;>= Shift-F1 ?
    jb    @get_kbd_line_25    ;No, then check next table
    cmp    ax,256+93        ;<= Shift-F10
    jg    @get_kbd_line_25    ;
    jmp    @sfn_key        ;Handle the shifted function key
@get_kbd_line_25:
    mov    cx,NUM_CMD_KEYS        ;size and...
    mov    bx,offset DGROUP:cmd_key_table    ;beginning of jump table
@get_kbd_line_30:            ;Loop begin
    cmp    ax,cs:[bx]        ;Is this the key ?
    je    @get_kbd_line_40    ;Hurrah, found
    inc    bx            ;point to next key
    inc    bx
    loop    @get_kbd_line_30    ;If more keys, repeat
    jmp    short @default_action    ;key not in table
@get_kbd_line_40:            ;Jump to location associated with
    jmp    word ptr cs:[bx+(2*NUM_CMD_KEYS)]    ;key

@quote:                    ;Insert next char
;                     without interpreting it
    mov    ah,7            ;get a raw keystroke (wd)
    call    near ptr getkey

@default_action:            ;Insert the character (in AX)
    call    near ptr store_char
    jc    @get_kbd_line_10    ;No room for char, keep looping
    mov    al,auto_recall_on    ;Are we auto-recalling ?
    or    al,al
    jz    @get_kbd_line_10    ;No
    call    near ptr execute_auto_recall
    jc    @get_kbd_line_10    ;If carry set, no matching
;                     string in history buffer
    mov    continue_recall,1    ;Else indicate auto-recall is
;                     still to go on
    jmp    @get_kbd_line_10


@char_left:                ;Cursor one char left
    call    near ptr char_left    ;char_left will return to top
    jmp    @get_kbd_line_10
;                     of editing loop

@char_right:                ;Cursor one char right
    call    near ptr char_right    ;char_right will return to top
    jmp    @get_kbd_line_10
;                     of editing loop

@word_left:                ;Cursor one word left
    call    near ptr word_left
    jmp    @get_kbd_line_10

@word_right:                ;Cursor one word right
    call    near ptr word_right
    jmp    @get_kbd_line_10

@bol:                    ;Beginning of line
    call    near ptr go_bol
    jmp    @get_kbd_line_10


@eol:                    ;End of line
    call    near ptr go_eol
    jmp    @get_kbd_line_10


@prev_line:                ;Get previous history line
    mov    ax,offset DGROUP:hist_back
@history_line:
    call    ax
    mov    ax,lastchar
    mov    dot,ax            ;Leave cursor at end of line
@history_search:
    jnc    @history_line_done    ;Line found
    call    near ptr strstk_settop    ;added by wd
    call    near ptr bell        ;No line
@history_line_done:
    jmp    @get_kbd_line_10

@next_line:                ;Get next history line
    mov    ax,offset DGROUP:hist_fwd
    jmp    short @history_line

@search_back:                ;Search back thru history buffer
    mov    ax,offset DGROUP:hist_bck_match
@search:
    mov    di,dot            ;Save current dot
    call    ax
    mov    dot,di            ;Restore it
    jmp    short @history_search

@search_forw:                ;Search forward thru history buffer
    mov    ax,offset DGROUP:hist_fwd_match
    jmp    short @search

@cycle_complete:
    or    CycleFlags,1
@complete:                ;Try to find a matching filename
    call    near ptr match_file
    cmp    auto_recall_on,1    ;Autorecall ongoing?
    je    short @del_eol        ;Yes, then delete to end of line
    jmp    @get_kbd_line_10

@del_left:                ;Delete char before cursor
    mov    ax,offset dgroup:char_left
    jmp    short @delete

@del_right:                ;Delete char at cursor
    mov    ax,offset dgroup:char_right
    jmp    short @delete


@del_prev_word:                ;Delete upto word beginning
    mov    ax,offset dgroup:word_left
    jmp    short @delete

@del_next_word:                ;Delete to start of next word
    mov    ax,offset dgroup:word_right
    jmp    short @delete

@del_bol:                ;Delete to beginning of line
    mov    ax,offset dgroup:go_bol
    jmp    short @delete


@toggle_insert:
    mov    ax,1
    xor    al,edit_mode        ;Toggle edit mode
    mov    edit_mode,al
    xchg    ax,bx
    add    bx,bx            ;Word offset
    mov    cx,omode_cursor[bx]    ;cx<-cursor shape
    mov    ah,01h            ;Set cursor size function
    IF    TOGGLE_CURSOR
    int    10h            ;BIOS
    ENDIF
    jmp    @get_kbd_line_10    ;Repeat editing loop

@abort_and_store:            ;Erases current line but remembers
;                     it in the history buffer
    call    near ptr remember
;    Fall through to erase line
@erase_line:
    call    near ptr go_bol        ;Move dot to beginning of line
;    fall thru to delete to end of line

@del_eol:                ;Delete to end of line
    mov    ax,offset dgroup:go_eol

@delete:                ;General purpose delete
    mov    si,dot            ;Remember the dot
    call    ax            ;Move dot to new position
    xchg    si,ax
    call    near ptr erase_to_dot    ;Delete characters between ax and dot
    jmp    @get_kbd_line_10

@twiddle:                ;added by wd
    mov    si,dot
    cmp    si,lastchar
    jne    @twiddle_10

    call    near ptr char_left
    jc    @ignore
    dec    si

@twiddle_10:
    call    near ptr char_left
    jc    @ignore

    xor    ah,ah
    push    ax
    xchg    si,ax
    call    near ptr erase_to_dot
    call    near ptr char_right
    pop    ax
    jmp    @default_action

@cooked_char:                ;added by wd
    mov    ah,8            ;get a cooked keystroke (wd)
    call    near ptr getkey
    jmp    @default_action

@autorecall:
    xor    auto_recall,1        ;Toggle auto recall mode
    jmp    @get_kbd_line_10

@macro:                 ;added by dfa
    xor    disable_macro,1     ;Toggle macro,symbol expansion disable
    jmp    @get_kbd_line_10


@vars:
; Expand the variables on the line.
    call    near ptr expand_var
    jmp    @get_kbd_line_10    ;Ignore return status from expand_var


@ignore:
    jmp    @get_kbd_line_10    ;Ignore the character


ctrl_key_table    LABEL    WORD
    dw    @ignore        ;NUL or ^@
    dw    @bol        ;^A
    dw    @char_left    ;^B
    dw    @cooked_char    ;^C (changed by wd - was @ignore)
    dw    @del_right    ;^D
    dw    @eol        ;^E
    dw    @char_right    ;^F
    dw    @abort_and_store ;^G
    dw    @del_left    ;^H
TAB_key_function label word    ; (label added by dfa)
    dw    @complete    ;^I
    dw    @vars        ;^J might have to be @ignore in order for input
;                 redirection to work properly but try for
;                 var expansion anyway.
    dw    @del_eol    ;^K
    dw    @del_prev_word    ;^L
    dw    @done_editing    ;^M
    dw    @next_line    ;^N
    dw    @del_eol_exec    ;^O
    dw    @prev_line    ;^P (changed by wd - was @ignore)
    dw    @quote        ;^Q
    dw    @search_back    ;^R
    dw    @ignore        ;^S
    dw    @twiddle    ;^T (changed by wd - was @ignore)
    dw    @prev_line    ;^U
    dw    @search_forw    ;^V
    dw    @del_next_word    ;^W
    dw    @del_bol    ;^X
    dw    @autorecall    ;^Y
    dw    @default_action    ;^Z
ESC_key_function label word    ; (label added by dfa)
    dw    @erase_line    ;^[ or ESC
BKS_key_function label word    ; (label added by wd)
    dw    @cycle_complete    ;^\
    dw    @ignore        ;^]
    dw    @done_wipeout    ;^^
    dw    @macro        ;^_ (changed by dfa - was @ignore)

cmd_key_table:                ;table of command keys
    dw    127    ;DEL
    dw    327    ;HOME
    dw    328    ;UP
    dw    331    ;LEFT
    dw    333    ;RIGHT
    dw    335    ;END
    dw    336    ;DOWN
    dw    338    ;INS
    dw    339    ;KDEL
    dw    371    ;CTLLEFT
    dw    372    ;CTLRIGHT
cmd_key_jumps:
    dw    @del_left    ;DEL
    dw    @bol        ;HOME
    dw    @prev_line    ;UP
    dw    @char_left    ;LEFT
    dw    @char_right    ;RIGHT
    dw    @eol        ;END
    dw    @next_line    ;DOWN
    dw    @toggle_insert    ;INS
    dw    @del_right    ;KDEL
    dw    @word_left    ;CTLLEFT
    dw    @word_right    ;CTLRIGHT


@sfn_key:
; A shifted function key has been struck.
; (Treat same as an unshifted function key).
@fn_key:
; A function key has been struck.
    call    near ptr expand_fnkey
    jc    @fn_key_20            ;Error or no expansion
    or    dx,dx                ;Line to be executed
;                         immediately ?
    je    short @done_editing_2        ;Yes, all done
@fn_key_20:
    jmp    @get_kbd_line_10        ;else keep editing

@del_eol_exec:                ;Deletes characters from the dot
;                     to end of the line and then
;                     executes the line
    mov    si,dot            ;Remember the dot
    call    go_eol
    xchg    si,ax
    call    near ptr erase_to_dot
    jmp    short @done_editing


@done_wipeout:
; The line is executed. However it is not stored in the history buffer and
; is also removed from the screen (this is a little klugy).
    mov    ax,offset DGROUP:linebuf
    mov    dot,ax
    mov    dx,lastchar
    mov    lastchar,ax            ;Temporarily pretend line
;                         is empty
    xchg    ax,dx
    push    ax
    call    near ptr set_disp_marks
    call    disp_line
    pop    ax
    mov    lastchar,ax            ;Restore line length
    jmp    short @get_kbd_line_90

@done_editing:
    call    near ptr remember    ;Store in history buffer
;                     Picks up line from global linebuf
@done_editing_2:
    call    near ptr disp_line    ;Necessry for @del_eol_exec,
;                     might as well do for others
    mov    ax,lastchar
    mov    dot,ax            ;Set dot to end of line
    call    near ptr line_to_scr    ;Set cursor beyond last character

@get_kbd_line_90:
    @DispCh CR            ;Do a carraige return because
;                     some applications like EDLIN
;                     only do a LF to go to next line
;    @DispCh LF            ;Go onto next line
;    all done
@get_kbd_line_99:
    @restore
    ret
get_kbd_line endp



;+
; FUNCTION : getkey
;
;    Read a keystroke, interpreting function keys into a 16-bit value.
;
; Parameters:
;    AH    = 7 for a raw keystroke, 8 for a cooked keystroke
;
; Returns:
;    AX    = 16-bit key value
; Register(s) destroyed:
;    DL
;-
; Requires AH be set to either 7 (raw) or 8 (cooked)
;
getkey proc near
    mov    dl,ah
    int    21h
    mov    ah,0
    or    al,al
    jne    @114        ;not '\0'
    mov    ah,0Bh
    int    21h        ;check if key available
    or    al,al
    jz    @113        ;no character available
    mov    ah,dl
    int    21h
    mov    ah,1
    jmp    short @114
@113:
    xor    ax,ax
@114:
    ret
getkey    endp



;+
; FUNCTION : expand_fnkey
;
;    Inserts the expansion corresponding to a symbol key into the
;    linebuffer. If the buffer is too small, only as many characters as
;    possible are inserted and the function returns an error. The
;    function also returns an error if the symbols is not defined. The
;    function also updates the displayed line. The function also checks
;    if the line is to be executed immediately or not, based on the last
;    character of the fn key expansion.
;
; Parameters:
;    AX    = function key character, must be between (256+59)-(256+68)
;          function keys and (256+84)-(256+93) for shifted functin keys.
;
; Returns:
;    CF    = 0 if no error, else 1
;          If CF is 1, then AX is 0 if symbol not found or non-zero
;          if symbol found but no room in line.
;    AX    = 1 if symbol was present
;          0 if symbol was not found.
;    DX    = 0 if the line is to be executed immediately
;          non-0 otherwise
;          DX is only valid if CF=0 and AX=1
; Register(s) destroyed:
;     <TBA>
;-
expand_fnkey proc near
    @save    si,di
    push    bp
    mov    bp,sp
    sub    sp,LINEBUF_SIZE
exp_buf    equ <byte ptr [bp-LINEBUF_SIZE]>

    mov    si,offset DGROUP:fnkey_tab    ;SI->'SFn'
    mov    dx,3                ;DX<-length of string
    mov    di,si
    sub    ax,256+59
    cmp    ax,10                ;Is it a function key
    jnb    @expand_fnkey_10        ;No, shifted function key
    inc    si                ;SI->'Fn'
    dec    dx                ;length of string is 2
    jmp    short @expand_fnkey_15
@expand_fnkey_10:
    sub    ax,84-59
@expand_fnkey_15:
    cmp    ax,9                ;F10 must appear as F0
    jne    @expand_fnkey_20
    mov    al,'0'-'1'
@expand_fnkey_20:
    add    al,'1'
    mov    2[di],al            ;Store in 'SFn' string
; OK now try and expand the symbol.
;                         SI->symbol
    mov    ax,LINEBUF_SIZE
    xchg    ax,dx                ;AX<-length of synbol
;                         DX<-length of expansion buffer
    lea    di,exp_buf
    call    near ptr get_symbol        ;Params SI,AX,DI,DX
    jc    @expand_fnkey_99        ;No symbol (buffer too
;                         small case not possible).
;                         AX will be 0 for this case.
; OK now we have the symbol expansion, so try insert it into the linebuffer.
;    AX contains length of expansion
    mov    si,di                ;SI->expansion
    add    di,ax
    dec    di                ;DI->last char of expansion
    xor    dx,dx
    mov    dl,byte ptr [di]
    sub    dl,fnkey_exec_char        ;Is this line to be
;                         immediately executed
    jne    @expand_fnkey_80        ;No
    dec    ax                ;The last char of expansion
;                         is a special char. Do not
;                         include it in the insert
;                         string
@expand_fnkey_80:
    push    dx
    call    near ptr insert_at_dot        ;Params SI,AX
;    pushf                    ;Save CF
;    call    disp_line
;    popf                    ;Restore CF
    mov    ax,1                ;AX<-exit code
    pop    dx                ;DX is 0 if line is to be
;                         executed immediately
@expand_fnkey_99:
    mov    sp,bp
    pop    bp
    @restore
    ret

expand_fnkey endp


;+
; FUNCTION : store_char
;
;    Stores    the character in AX into the line buffer if max line
;    length will not be exceeded. Characters may be inserted or
;    overwrite chars in the buffer depending on the edit mode and whether
;    auto-recall is on.
;
; Parameters:
;    AX    = character
;
; Returns:
;    CF    = 0 if no error, else 1
; Register(s) destroyed:
;     <TBA>
;-
store_char proc near
    @save    si
    cmp    ax,256            ;char >= 256
    jnb    @store_char_90        ;Ignore if so
    cmp    edit_mode,0        ;1 if insert mode
    je    @store_char_20        ;Jump if overtype mode
    cmp    auto_recall_on,1    ;Is auto-recall on ?
    je    @store_char_20        ;Yes, behave as if in overtype mode
    mov    si,offset dgroup:tempchar ;temporary storage
    mov    [si],al            ;Store char
    mov    ax,1            ;Length of string
    call    near ptr insert_at_dot    ;Insert the character
    jnc    @store_char_99        ;No problemo
    jmp    short @store_char_90    ;No room in buffer
@store_char_20:
    mov    si,dot            ;Current position in line
    cmp    si,LINEBUF_END        ;At line end?
    jae    @store_char_90
;    Enough room for a char
    mov    [si],al            ;Store the char
    mov    dx,si            ;DX->changed character
    mov    ax,si
    inc    ax            ;AX->char after change
    mov    dot,ax            ;Store it as new dot position
    cmp    si,lastchar        ;Was it end of line ?
    jb    @store_char_30
    mov    lastchar,ax        ;Store new end of line
@store_char_30:
    call    near ptr set_disp_marks    ;ax,dx parameters
    clc                ;Indicate no error
    jmp    short @store_char_99
@store_char_90:
    call    near ptr bell
    stc                ;Indicate error
@store_char_99:
    @restore
    ret
store_char endp


;+
; FUNCTION : word_left
;
;    Move one word left.
;
; Parameters:
;    Globals linebuf and dot.
;
; Returns:
;    CF = 1 if dot was at beginning of the line already
;         0 otherwise.
; Register(s) destroyed:
;-
word_left proc near
@word_left_10:
    call    near ptr char_left    ;Move one char left
    jc    @word_left_99        ;Already at beginning of line
@word_left_12:
    ;Loop to backup over non-alphanum
    call    near ptr isalphnum    ;AL alphanumeric?
    jnc    @word_left_15        ;Yes
    call    near ptr char_left    ;One char left.
                    ;AL<-char at dot
    jnc    @word_left_12        ;Not at beginning of line
@word_left_15:                ;Now backup to beginning of word
;    At this point, dot is always at a alphabetic char or beginning
;    of the line
    call    near ptr char_left
    jc    @word_left_98        ;Were already at beginning of line
    call    near ptr isalphnum    ;Alphanumeric?
    jnc    @word_left_15        ;Yes, loop back
                    ;Found non-alphanumeric char
    call    near ptr char_right    ;move over one
@word_left_98:
    clc                ;Clear carry flag
@word_left_99:
    ret
word_left endp



;+
; FUNCTION : word_right
;
;    Move one word right.
;
; Parameters:
;    Globals linebuf and dot.
;
; Returns:
;    Nothing.
; Register(s) destroyed:
;-
word_right proc near
@word_right_10:                ;Loop fwd over alphanumerics
    call    near ptr char_right    ;One char right
                    ;AL<-char at dot
    jc    @word_right_99        ;Already at end of line
    call    near ptr isalphnum    ;Is AL alphanumeric ?
    jnc    @word_right_10        ;Yes, loop back
@word_right_15:                ;Now move to beginning of word
    call    near ptr char_right
    jc    @word_right_99        ;Already at end of line
    call    near ptr isalphnum    ;Alphanumeric?
    jc    @word_right_15        ;Not alphanum char, loop back
@word_right_99:
    ret
word_right endp




;+
; FUNCTION : char_left
;
;    Moves the 'dot' one character to the left unless
;    already at the beginning of the line.
;
; Parameters:
;    Global    dot is current position in the line.
;
; Returns:
;    AL    = char at new dot position.
;    CF    = 1 if OLD dot was at beginning of line
;          0 otherwise.
; Register(s) destroyed:
;-
char_left proc    near
    @save    si
    mov    ax,dot            ;Current position in line
    cmp    ax,offset dgroup:linebuf
    jne    @char_left_5
    stc                ;Dot already at beginning of line
    jmp    short @char_left_99
@char_left_5:
    dec    ax            ;Move dot left
    mov    dot,ax
@char_left_99:
    xchg    ax,si
    lodsb                ;AL<-char at dot
    @restore
    ret
char_left endp







;+
; FUNCTION : char_right
;
;    Moves the 'dot' one character to the right unless
;    already at the end of the line.
;
; Parameters:
;    Global    dot is current position in the line.
;
; Returns:
;    AL    = char at new dot position. Undefined if new dot is at
;          the end of the line.
;    CF    = 1 if OLD dot was already at end of the line.
;          0 otherwise.
; Register(s) destroyed:
;-
char_right proc    near
    @save    si
    mov    si,dot            ;Current position in line
    mov    ax,lastchar        ;AX->Beyond last char
    dec    ax            ;AX->last char in line
    cmp    ax,si            ;Dot at end ?
    jc    @char_right_99        ;Already at line end
    inc    si            ;Move dot right, CF not affected
    mov    dot,si
    lodsb                ;AL<-char at dot, (undefined if
;                     dot is now at end of line).
;    CF    already clear
@char_right_99:
    @restore
    ret
char_right endp



;+
; FUNCTION : go_bol
;
;    Sets    dot to pint to the beginning of the line
;
; Register(s) destroyed: None.
;-
go_bol    proc    near
    mov    dot,offset dgroup:linebuf
    ret
go_bol    endp



;+
; FUNCTION : go_eol
;
;    Sets    dot to pint to the end of the line
;
; Register(s) destroyed: AX.
;-
go_eol    proc    near
    mov    ax,lastchar
    mov    dot,ax
    ret
go_eol    endp




;+
; FUNCTION : match_file
;
;    match_file tries to expand the filename to the left of the
;    cursor. If there are several matching files, the longest common
;    prefix is placed on the line.
;    Added by wd:    If no characters can be placed on the line,
;            list the possible matches.  Alternately, add
;            one match at a time to the line.
;
; Parameters:
;    None.
;
; Returns:
;    Nothing.
; Register(s) destroyed:
;-
match_file proc    near
    @save    si,di
    push    bp
    mov    bp,sp
    sub    sp,64+44+2+2+2+2+2
pathbuf        equ    64        ;Storage for entire filename with path
ffblk        equ    pathbuf+44
ffblk_attr     equ    ffblk-15h    ;Attr byte within ffblk
ffblk_name     equ    ffblk-1Eh    ;filename within ffblk
lineptr        equ    ffblk+2
remaining    equ    lineptr+2    ;Remembers remaining space in path
oldDTAseg     equ    remaining+2
oldDTAoff     equ    oldDTAseg+2
breakstate    equ    oldDTAoff+2    ;Remembers break state

    mov    ax,3300h        ;Get current break state
    int    21h            ;DL<-current break state
    mov    byte ptr [bp-breakstate],dl ;Remember it
    xor    dl,dl
    mov    ax,3301h        ;Disable break check during
;                     disk i/O
    int    21h

    push    es
    @GetDTA                ;Get and save old DTA
    mov    [bp-oldDTAseg],es
    mov    [bp-oldDTAoff],bx
    pop    es
;
    lea    dx,[bp-ffblk]
    @SetDTA    dx            ;Set DTA to our DTA

; If the last call was also a cycle, continue what we started (wd,dfa)
    cmp    CycleFlags,7
    je    @match_file_60

;    lea    di,[bp-pathbuf]        ;OK 'cause SS==DS (removed by wd)
    mov    si,dot            ;Current line position
    mov    olddot,si        ;Remember current dot position (wd)
    mov    cx,63            ;Max length of path
@match_file_10:
    cmp    si,offset dgroup:linebuf
    je    @match_file_51        ;Beginning of line and filename
    dec    si
    mov    al,[si]            ;AL<-next char
@match_file_25:
    call    near ptr isspace
    je    @match_file_50        ;Beginning of filename
@match_file_45:                ;Check for next char if
;                     pathname not too long
    loop    @match_file_10
    jmp    @match_file_90        ;Pathname too long, just exit
@match_file_50:
    inc    si
@match_file_51:
    mov    [bp-lineptr],si        ;Save start of path name in linebuf
    mov    ax,63
    sub    ax,cx            ;Length of name
    mov    [bp-remaining],cx    ;remember num bytes left in pathbuf
    xchg    ax,cx            ;CX<-length of name
;    jcxz    @match_file_90        ;No name, just exit (removed by wd)

    call    near ptr @match_file_parse

    lea    dx,[bp-pathbuf]        ;dx->ASCII name
    @GetFirst dx,16            ;Include subdirs in search
    jnc    @match_file_70        ;No error
@match_file_58:
    mov    ffblk_save,0        ;Make sure the DTA will fail a GetNext
    call    near ptr bell        ;No files found
    jmp    @match_file_90        ;Restore DTA and exit

@match_file_60:
    mov    cx,FFBLK_SAVE_SIZE/2    ;5 lines by dfa and wd
    mov    si,offset ffblk_save
    lea    di,[bp-ffblk]
    rep     movsw            ;restore the DTA for the GetNext
    and    CycleFlags,3        ;Don't need more than this now
@match_file_65:
    @GetNext            ;Get the next file name
    jnc    @match_file_70        ;Got one
    mov    ax,olddot        ;AX->start of chars to be deleted
    call    near ptr erase_to_dot    ;Delete characters between dot
    mov    CycleFlags,1            ;If next key is cycle,  want to do
    jmp    short @match_file_58    ;it immediately

@match_file_70:                ;At least one file found
    lea    di,[bp-pathbuf]        ;DI->pathbuf
    lea    si,[bp-ffblk_name]    ;Name returned by GetFirst
    cmp    byte ptr [si],'.'    ;Is this '.' or '..'?
    je    @match_file_65        ;Yes, ignore it
@match_file_71:                ;Copy the file name
    lodsb
    stosb
    or    al,al
    jne    @match_file_71

    mov    ax,SPACE        ;If file, add a space (ah = 0 -- wd)
    test    byte ptr [bp-ffblk_attr],16 ;Subdirectory?
    je    @match_file_72        ;No
    mov    al,backslash_char    ;If subdir, (possibly) add a backslash
@match_file_72:
    mov    word ptr [di-1],ax    ;Add a space or a '\' and a null

    cmp    CycleFlags,3        ;If cycling, bug out (wd,dfa)
    je    @match_file_79

;    Now hunt for more files. For each file found, keep the longest
;    prefix in common so far.

    @GetNext            ;Get the next file name
    jc    @match_file_80        ;No more files

    lea    di,[bp-pathbuf]        ;DI->start of file name
    lea    si,[bp-ffblk_name]    ;Name returned by GetNext
    mov    cx,13            ;Max Length of field
    repe    cmpsb            ;Compare strings
    xor    ax,ax            ;Terminating null for [di-1]
    jmp    short @match_file_72    ;Try for more files

@match_file_79:
    mov    cx,FFBLK_SAVE_SIZE/2    ;4 lines by dfa and wd
    lea    si,[bp-ffblk]
    mov    di,offset ffblk_save
    rep    movsw            ;save ffblk for next call

@match_file_80:
;    Found one or more files, copy the longest common prefix
;    into the line buffer
;following 2 lines moved by wd
;    mov    ax,[bp-lineptr]        ;AX->start of chars to be deleted
;    call    near ptr erase_to_dot    ;Delete characters between dot
;                     and start of name
    lea    si,[bp-pathbuf]        ;SI->name to be copied
    mov    di,si
    xor    al,al
    mov    cx,64
    repne    scasb            ;Hunt for terminating null
    mov    ax,63
    sub    ax,cx            ;AX<-length of string

;following 10 lines added by wd & dfa
    cmp    CycleFlags,3        ;If cycling, no length check
    je    @match_file_85
    mov    dx,dot
    sub    dx,fnameptr        ;DX<-length of search string
    cmp    ax,dx
        ja      @match_file_85          ;If cycling,  we want first call
        jb      @match_file_list        ;not to actually cycle,  but just
    test    CycleFlags,1            ;complete to longest common prefix
        jz        @match_file_list
       jbe    @match_file_list

@match_file_85:
    test    CycleFlags,1
    jnz    @match_file_87             ;If next key is cycle,  want to do
    mov    CycleFlags,1           ;it immediately (dfa)

@match_file_87:
; SI->string, AX is length
    push    ax
    call    near ptr xlate_lower    ;Convert to lowercase
;ok, these 2 lines removed above can now do their work - wd
    mov    ax,fnameptr        ;AX->start of chars to be deleted
    call    near ptr erase_to_dot    ;Delete chars between dot and start
    pop    ax
    call    near ptr insert_at_dot    ;SI->source, AX == length

@match_file_90:
    push    ds
    mov    ds,[bp-oldDTAseg]
    mov    dx,[bp-oldDTAoff]
    @SetDTA    dx            ;Restore DTA
    pop    ds
; Restore previous state of break checking
    mov    dl,byte ptr [bp-breakstate]
    mov    ax,3301h
    int    21h
    mov    sp,bp
    pop    bp
    @restore
    ret

; remainder of this file extensively modified by wd
@match_file_list:
    mov    CycleFlags,1            ;If next key is cycle,  want to do
                       ;it immediately (dfa)
    mov    si,[bp-lineptr]
    mov    cx,dot
    sub    cx,si
    call    near ptr @match_file_parse

    call    near ptr output_newline
    lea    dx,[bp-pathbuf]
    @GetFirst dx,16

@match_file_list_10:
    lea    si,[bp-ffblk_name]
    cmp    byte ptr [si],'.'    ;Is this '.' or '..'?
    je    @match_file_list_55    ;Yes, ignore it
    mov    cx,15

@match_file_list_20:
    lodsb
    test    al,al
    jz    @match_file_list_30
    call    near ptr tolower
    @DispCh al
    dec    cx
    jmp    @match_file_list_20

@match_file_list_30:
    mov    al,SPACE
    test    byte ptr [bp-ffblk_attr],16    ;Subdirectory?
    je    @match_file_list_40        ;No
    mov    al,'\'                ;If subdir, add a backslash
@match_file_list_40:
    @DispCh al
@match_file_list_50:
    @DispCh SPACE
    loop    @match_file_list_50
@match_file_list_55:
    @GetNext
    jnc    @match_file_list_10

    call    near ptr get_curpos        ;DX<-current cursor position
    test    dl,dl
    jz    @match_file_list_60
    call    near ptr output_newline
@match_file_list_60:
    call    near ptr disp_prompt
    call    near ptr get_curpos        ;DX<-current cursor position
    mov    initial_currow,dh
    mov    ax,lastchar
    mov    dx,offset DGROUP:linebuf
    call    near ptr set_disp_marks
    call    disp_line            ;Redisplay line
    jmp    @match_file_90
match_file endp

@match_file_parse proc near
;   Copy filename into ASCIIZ buffer
;   SI->first char of filename in line buffer, CX=length
    xor    dx,dx            ;Flags
    lea    di,[bp-pathbuf]        ;OK 'cause SS==DS
    mov    fnameptr,si        ;Assumed start of filename in linebuf
    jcxz    @match_file_p42
@match_file_p0:
    lodsb                ;AL<-next char
    stosb                ;Store it
    cmp    al,'.'
    jne    @match_file_p10
    or    dl,1            ;Set flag to remember file type '.'
    jmp    short @match_file_p40    ;Check out next character
@match_file_p10:
    cmp    al,':'            ;Disk?
    je    @match_file_p30
    cmp    al,'\'            ;Directory separator?
    je    @match_file_p20
    cmp    al,'/'            ;Same thing
    jne    @match_file_p40
@match_file_p20:
    cmp    backslash_char,0    ;is backslash appending turned on?
    je    @match_file_p30        ;no
    mov    backslash_char,al    ;remember the type of slash (/ or \)
@match_file_p30:
    mov    fnameptr,si        ;Update start of filename in linebuf
    and    dl,0FEh            ;Forget file type flag

@match_file_p40:
    loop    @match_file_p0

@match_file_p42:
    mov    cx,[bp-remaining]    ;CX<-remaining space
    jcxz    @match_file_p50        ;Only space for terminator
    mov    al,'*'
    stosb                ;Attach a '*'
    cmp    cl,3            ;Enough space for ".*"
    jb    @match_file_p50
    and    dl,1            ;Saw a file type ?
    jne    @match_file_p50        ;Yes, go attach terminator
    mov    [di],2A2Eh        ;Attach a ".*"
    inc    di
    inc    di
@match_file_p50:
    xor    al,al            ;AL<-0
    stosb                ;Terminating 0
    ret
@match_file_parse endp


CSEG    ENDS

    END