C/C++ Users Group Library 1996 July/C-C++ Users Group Library July 1996.iso/vol_100/169_01/xenix.asm

Assembly Source File | 1984-07-27 | 7.1 KB | 342 lines

title MSDOS 2.00 Function Library for Lattice C
;
;........................................
;.                    .
;.    DOS 2.00 Functions for        .
;.           Lattice            .
;.                    .
;.    T. Jennings 23 June 83        .
;.      created 13 Sept 82        .
;.                    .
;........................................
;
;MSDOS 2.00 support for Lattice. These will NOT
;work for version 1.xx of DOS. All support full
;paths. The function names are the same as the
;standard library names with "_x" prepended, to
;accomodate my file system nameing heirarchy.
;
;NOTE: You cannot mix these calls with the
;Lattice library calls: i.e. open with _xopen()
;and write with open(). You must use ALL or
;NONE.
;
;These functions all use the DOS buffers.
;
;Detailed info is given in the title block for
;each function. A quick description follows.
;
;handle= _xopen(pathname,access);
;int handle,access;
;char *pathname;
;
;    Open a file. handle returns either
;the DOS handle, or -1 if error (file not
;found). Access is: 0 == read only, 1 == write
;only, 2 == read/write.
;
;handle= _xcreate(pathname,access);
;
;    Create a new file, delete any existing
;copy. Access is not used: use 0. Returns the
;handle or -1 if error.
;
;v= _xread(handle,buffer,count);
;v= _xwrite(handle,buffer,count);
;int v,handle,count;
;char *buffer;
;
;    File read or write to an opened or
;created file. reads or writes 'count' bytes
;to the file 'handle', to or from 'buffer'.
;Returns the number of bytes processed: equal
;to 'count' if sucessful.
;
;error= _xclose(handle)
;int error;
;
;    Close an open file. Returns -1 if
;error. Any buffers are flushed at this point.
;
;_xdelete(pathname);
;
;    Remove the file from the file
;system.
;
;fsize= _fsize(pathname);
;long fsize;
;
;    Returns the size of the file in bytes.
;Returns 0 if no file. Do NOT call inbetween
;calls to _xfind().
;
;found= _xfind(pathname,filename,&fsize,attrib,flag);
;int found,flag,attrib;
;char *pathname,filename[14];
;long fsize;
;
;Search for the specified pathname. flag should
;be 0 for the first call, non-zero for all
;subsequent calls. _xfind() returns true if a
;match was found, and the found file is
;returned in filename[], in ASCIZ format.
;Attrib is the DOS attributes to match; I
;will not describe that mess here. _xfind()
;returns the size of the file in fsize. (Don't
;forget to pass the address of fsize.)
; For example:
;
;int i;
;char filename[14];
;long fsize;
;
;    i= 0;
;    while (_xfind("\\bin\\*.*",filename,&fsize,0,i)) {
;        printf("File: %14s Size: %lu\n",filename,fsize);
;        ++i;
;    }
;    printf("%u matching files.\n",i);
;
;Prints the names of all matching disk files.
;Any other calls (except_fsize()) can be made
;in between calls to _xfind().
;
dgroup group data
pgroup group prog

prog segment byte public 'prog'

public    _xopen,_xcreate,_xclose
public    _xread,_xwrite
public    _xfind
public    _fsize
public     _xdelete
assume cs:pgroup,ds:dgroup
;;
;;    handle= _xcreate(name,access)
;;    handle= _xopen(name,access)
;;
;;    int handle;        -1 if error,
;;    int access;        0=r, 1=w, 2=r/w
;;    char *name;        null terminated
;;
;;Open and create functions. The name is a null
;;terminated string. The access byte is passed
;;directly to DOS. All errors are translated to
;;a -1 return value.
;;
_xopen proc near
    mov    ah,61
    jmp    short opncrt
_xcreate proc near
    mov    ah,60

opncrt:    push    bp
    mov    bp,sp
    mov    dx,[bp+4]    ;pathname,
    mov    al,[bp+6]    ;access,
    xor    bx,bx
    xor    cx,cx
    int    21h        ;do it,
    jnc    opncrt1
    mov    ax,-1        ;error!
opncrt1:pop    bp
    ret

_xcreate endp
_xopen endp
;;
;;xclose(handle)
;;int handle;
;;
;;Close a handle opened by XOPEN or XCREATE.
;;Returns -1 if close error.
;;
_xclose proc near
    mov    ah,62
    push    bp
    mov    bp,sp
    mov    bx,[bp+4]    ;handle,
    int    21h
    pop    bp
    ret

_xclose endp
page
;;
;;    count= xread(handle,buffer,size)
;;    count= xwrite(handle,buffer,size)
;;
;;    int count;    bytes actually r/w
;;    int handle;
;;    char *buffer;
;;    int size;    byte count,
;;
;;    Read or write (size) bytes from the
;;file (handle). The return value is the number
;;of bytes actually processed.
;;
;;    No text translation is done. All
;;bytes are processed as read or written. No
;;check is done (or is possible) on the buffer
;;size.
;;
_xread proc near
    mov    ah,63
    jmp    short rdwrt
_xwrite proc near
    mov    ah,64

rdwrt:    push    bp
    mov    bp,sp
    mov    bx,[bp+4]    ;handle,
    mov    cx,[bp+8]    ;count,
    mov    dx,[bp+6]    ;buffer,
    int    21h
    pop    bp
    ret

_xwrite endp
_xread endp
page
;;
;;    ret= xfind(path,name,size,attrib,first)
;;    int ret;        0 if no match
;;    char *path;
;;    char *name;        dest name,
;;    long *size;        ptr to file siz
;;    int attrib;        attributes
;;    int first;        0 if 1st time,
;;
;;Find the Nth occurence of pathname. Returns
;;0 when no match. Only the filename portion
;;can contain wildcards. The returned filename
;;does not contain the path portion of the
;;input string.
;;    Not recursive. Do not call _FSIZE
;;inbetween _XFIND calls.
;;
xfpath    equ    4    ;path pointer,
xfname    equ    6    ;retnd name,
xfsize    equ    8    ;file size ptr,
xfaccess equ    10    ;access,
xfflag    equ    12    ;first time flag,

_xfind proc near
    push    bp
    mov    bp,sp
    mov    ah,26        ;set DMA addr
    mov    dx,offset dgroup:xfbuf
    int    21h        ;to buffer,
    test word ptr [bp+xfflag],-1
    mov    ah,78        ;do right call,
    jz    xf1
    mov    ah,79        ;0 == 1st time,
xf1:    mov    dx,[bp+xfpath]    ;path name,
    mov    cx,[bp+xfaccess];access,
    int    21h
    mov    ax,0        ;ret if no
    jc    xfr        ;match,
;
;Copy the file size in.
;
    mov    bx,[bp+xfsize]    ;size ptr,
    mov    ax,fsize
    mov    [bx],ax
    mov    ax,fsize+2
    mov    [bx+2],ax

    mov    di,[bp+xfname]    ;dest string,
    mov    si,offset dgroup:fname
    mov    cx,12
    cld
;
;Fix a "slight" XENIX bug: Delete trailing
;spaces, else it fails OPENs.
;
xf2:    lodsb            ;get a byte,
    cmp    al,0        ;if null
    je    xf3
    cmp    al,' '        ;or space,
    je    xf3        ;stop,
    stosb
    loop    xf2        ;max 11 chars
xf3:    mov byte ptr [di],0    ;terminate,
    mov    ax,1        ;good return.
xfr:    pop    bp
    ret
_xfind endp
page
;;
;;    fsize= _fsize(filename)
;;    long fsize;
;;    char *filename;
;;
;;Return the size of a file, in bytes. Returns
;;0 if file not found. Filename can contain
;;a path.
;;
;;Cannot be called in between any _XFIND calls.
;;
_fsize proc near
    push    bp
    mov    bp,sp
    mov    ah,26        ;set DMA addr
    mov    dx,offset dgroup:xfbuf
    int    21h        ;to buffer,
    mov    ah,78        ;search 1st,
xs1:    mov    dx,[bp+4]    ;path name,
    mov    cx,0
    int    21h
    mov    ax,0        ;ret if no
    mov    bx,0        ;match,
    jc    xsr

    mov    bx,fsize
    mov    ax,fsize+2
xsr:    pop    bp
    ret
_fsize endp
page
;
;error= _xdelete(path);
;int error;
;char *path;
;
_xdelete proc near
    push    bp
    mov    bp,sp
    mov    dx,[bp+4]
    mov    ah,41h
    int    21h
    mov    ax,0
    sbb    ax,0
    pop    bp
    ret
_xdelete endp

prog ends
page
data segment word public 'data'
;
;Structure for the FindFirst and FindNext
;function XFIND. NOT REENTRANT.
;
xfbuf    db    (?)    ;search attrib
    db    (?)    ;drive,
    db 11 dup (?)    ;name,
    dw    (?)    ;last ent
    dd    (?)    ;DPB,
    dw    (?)    ;dir start

    db    (?)    ;attrib found,
    dw    (?)    ;time?
    dw    (?)    ;date?
fsize    dw    (?)    ;size low
    dw    (?)    ;size hi,
fname    db 13 dup (?)    ;packed name,

data ends

    end