Liren Large Software Subsidy 5/05.iso/a/a069/1.img/TRSOURCE.EXE/_TR_FILE.ASM

Assembly Source File | 1990-10-22 | 10.0 KB | 354 lines

;  _TR_FILE.ASM
;
;  by Leonard Zerman, Ralph Davis
;
; Placed in the public domain by Tom Rettig Associates, 10/22/1990.
;

          PUBLIC __TR_OPEN,   __TR_CREAT,  __TR_READ
          PUBLIC __TR_WRITE,  __TR_LSEEK,  __TR_CLOSE
          PUBLIC __TR_RENAME, __TR_UNLINK, __TR_TELL
;***************************************************************
;
; This file contains TR-LIB file handling routines
; designed to be compatible with C's low level
; file handling functions.
;
; Functions included (and their equivalent C function):
;
;     __TR_OPEN     open(filename, mode);
;     __TR_CREAT    creat(filename, file_attribute);
;     __TR_READ     read(file_descriptor, destination, length);
;     __TR_WRITE    write(file_descriptor, source, length);
;     __TR_CLOSE    close(file_descriptor);
;     __TR_LSEEK    lseek(file_descriptor, offset, seek_mode);
;     __TR_RENAME   rename(old_filename,new_filename);
;     __TR_UNLINK   unlink(filename);
;
; Also included (with no low-level C equivalent):
;
;     __TR_TELL     corresponds to ftell(file_pointer);
;                  /* uses file_descriptor instead */
;
;****************************************************************

;****************************************************************
_TR_FILE_TEXT SEGMENT  BYTE PUBLIC 'CODE'
         ASSUME   CS:_TR_FILE_TEXT
;-------------------------------------------------

;     file_descriptor = __tr_open(filename, mode)
;
;        int file_descriptor;
;        char *filename;
;        int mode;
;
;        Returns:  DOS file handle if successful, -1 if not.
;
;----------
__TR_OPEN  PROC    FAR
          PUSH    BP
          MOV     BP,SP
          PUSH    BX
          PUSH    DX
          PUSH    DS
          LDS     DX,[BP+6]       ; Get filename address
          MOV     AX,[BP+10]      ; Get open mode
          MOV     AH,3DH
          INT     21H
          JNC     _TR_OPEN_EXIT   ; File descriptor is in AX
          XOR     AX,AX           ; Return -1 if error
          DEC     AX
_TR_OPEN_EXIT:
          POP     DS
          POP     DX
          POP     BX
          POP     BP
          RET
__TR_OPEN  ENDP
;------------------------------------------------
;
;     file_descriptor = __tr_creat(filename, file_attribute)
;
;        int file_descriptor;
;        char *filename;
;        int file_attribute;
;
;        Returns:  DOS file handle if successful, -1 if not.
;
;     File attributes are defined in TRLIB.H as follows:
;
;            #define FL_NORMAL  0
;            #define FL_RDONLY  1
;            #define FL_HIDDEN  2
;            #define FL_SYSTEM  4
;            #define FL_ARCHIVE 0x20
;
; NOTE:  This syntax differs slightly from C syntax.
;        C specifies that the second argument is the privilege
;        mode of the file.  DOS function 3CH, which
;        this function uses, expects the second argument
;        to be the file attribute (read-only, system, hidden,
;        normal, etc.).
;
;----------------
__TR_CREAT PROC    FAR
          PUSH    BP
          MOV     BP,SP
          PUSH    BX
          PUSH    DX
          PUSH    DS
          LDS     DX,[BP+6]       ; Get filename address
          MOV     CX,[BP+10]      ; Get file attribute
          MOV     AH,3CH
          INT     21H
          JNC     _TR_CREAT_EXIT  ; AX contains file descriptor
          XOR     AX,AX
          DEC     AX              ; return -1 if error
_TR_CREAT_EXIT:
          POP     DS
          POP     DX
          POP     BX
          POP     BP
          RET
__TR_CREAT  ENDP
;------------------------------------------------
;
;     status = _tr_read(file_descriptor, destination, length);
;
;        int status;
;        int file_descriptor;
;        char *destination;
;        int length;
;
;        Returns:  number of bytes read if successful, -1 if not.
;
;--------------
__TR_READ PROC     FAR
         PUSH     BP
         MOV      BP,SP
         PUSH     BX
         PUSH     CX
         PUSH     DX
         PUSH     DS
         MOV      BX,[BP+6]   ; get file descriptor
         LDS      DX,[BP+8]   ; get address of buffer
         MOV      CX,[BP+12]  ; get number of bytes to read
         MOV      AH,3FH
         INT      21H
         JNC      _TR_READ_EXIT   ; AX contains number of bytes read
         XOR      AX,AX       ; Return -1 for error
         DEC      AX
_TR_READ_EXIT:
         POP      DS
         POP      DX
         POP      CX
         POP      BX
         POP      BP
         RET
__TR_READ ENDP
;------------------------------------------------------
;
;     status = __tr_write(file_descriptor, source, length);
;
;        int status;
;        int file_descriptor;
;        char *source;
;        int length;
;
;        Returns:  number of bytes written, -1 if error.
;
;-----------
__TR_WRITE PROC     FAR
         PUSH     BP
         MOV      BP,SP
         PUSH     BX
         PUSH     CX
         PUSH     DX
         PUSH     DS
         MOV      BX,[BP+6]   ; get file descriptor
         LDS      DX,[BP+8]   ; get address of buffer
         MOV      CX,[BP+12]  ; get number of bytes to write
         MOV      AH,40H
         INT      21H
         JNC      _TR_WRITE_EXIT  ; AX contains number of bytes written
         XOR      AX,AX       ; return -1 for error
         DEC      AX
 _TR_WRITE_EXIT:
         POP      DS
         POP      DX
         POP      CX
         POP      BX
         POP      BP
         RET
__TR_WRITE ENDP
;------------------------------------------------------
;
;     status = _tr_close(file_descriptor);
;
;        int status;
;        int file_descriptor;
;
;        Returns:  0 if successful, -1 if not.
;
;------------
__TR_CLOSE  PROC   FAR
          PUSH   BP
          MOV    BP,SP
          PUSH   BX
          MOV    BX,[BP+6]        ; get file descriptor
          MOV    AH,3EH
          INT    21H
          JNC    _TR_CLOSE_GOOD
          XOR    AX,AX
          DEC    AX
          JMP    SHORT _TR_CLOSE_EXIT
_TR_CLOSE_GOOD:
          XOR    AX,AX           ; return 0 if successful
_TR_CLOSE_EXIT:
          POP    BX
          POP    BP
          RET
__TR_CLOSE  ENDP
;---------------------------------------------
;
;     position = _tr_lseek(file_descriptor, offset, seek_mode);
;
;        long position;
;        int  file_descriptor;
;        long offset;
;        int  seek_mode;
;
;        Returns:  New file position if successful, -1L if not.
;
;----------
__TR_LSEEK PROC     FAR
         PUSH     BP
         MOV      BP,SP
         PUSH     CX
         PUSH     DS
         PUSH     SI
         MOV      BX,[BP+6]   ; get file handle
         MOV      DX,[BP+8]   ; get low word of seek offset
         MOV      CX,[BP+10]  ; get high word of seek offset
         MOV      AL,[BP+12]  ; get offset mode
         MOV      AH,42H
         INT      21H
         JNC      _TR_LSEEK_GOOD  ; DX:AX contains new file position
         MOV      DX,0FFFFH   ; return -1L for error
         MOV      AX,0FFFFH
         JMP      SHORT _TR_LSEEK_EXIT
_TR_LSEEK_GOOD:
_TR_LSEEK_EXIT:
         POP      SI
         POP      DS
         POP      CX
         POP      BP
         RET
__TR_LSEEK ENDP
;------------------------------------------------------
;
;     position = _tr_tell(file_descriptor);
;
;        long position;
;        int  file_descriptor;
;
;        Returns:  Current file position if successful, -1L if not.
;
;------------
__TR_TELL PROC     FAR
         PUSH     BP
         MOV      BP,SP
         PUSH     CX
         PUSH     DS
         PUSH     SI
         MOV      BX,[BP+6]   ; get file handle
         MOV      AL,1        ; seek from current location
         XOR      DX,DX       ; seek 0 bytes
         XOR      CX,CX
         MOV      AH,42H
         INT      21H
         JNC      _TR_TELL_GOOD  ; DX:AX contains new file position
         MOV      DX,0FFFFH   ; return -1L for error
         MOV      AX,0FFFFH
         JMP      SHORT _TR_TELL_EXIT
_TR_TELL_GOOD:
_TR_TELL_EXIT:
         POP      SI
         POP      DS
         POP      CX
         POP      BP
         RET
__TR_TELL ENDP
;------------------------------------------------------
;
;     error = _tr_rename(old_filename,new_filename);
;
;        int error;
;        char *old_filename;
;        char *new_filename;
;
;        Returns:  0 if successful, -1 if not
;
;-------------
__TR_RENAME PROC   FAR
         PUSH     BP
         MOV      BP,SP
         PUSH     DS
         PUSH     ES
         PUSH     DX
         PUSH     DI
         LDS      DX,[BP+6]     ; get address of old filename
         LES      DI,[BP+10]    ; get address of new filename
         MOV      AH,56H
         INT      21H
         JNC      _TR_REN_GOOD
         XOR      AX,AX         ; return -1 if error
         DEC      AX
         JMP      SHORT _TR_REN_EXIT
_TR_REN_GOOD:
         XOR      AX,AX         ; return 0 for successful execution
_TR_REN_EXIT:
         POP      DI
         POP      DX
         POP      ES
         POP      DS
         POP      BP
         RET
__TR_RENAME ENDP
;-------------------------------------------------------
;
;     error = _tr_unlink(filename);
;
;        int error;
;        char *filename;
;
;     Returns:  0 if successful, -1 if not.
;
;------------
__TR_UNLINK PROC   FAR
           PUSH   BP
           MOV    BP,SP
           PUSH   DS
           PUSH   DX
           LDS    DX,[BP+6]       ; get filename
           MOV    AH,41H
           INT    21H
           JNC    _TR_UNLINK_GOOD
           XOR    AX,AX           ; return -1 for error
           DEC    AX
           JMP    SHORT _TR_UNLINK_EXIT
_TR_UNLINK_GOOD:
           XOR    AX,AX
_TR_UNLINK_EXIT:
           POP    DX
           POP    DS
           POP    BP
           RET
__TR_UNLINK ENDP
;--------------------------------------------------------
_TR_FILE_TEXT    ENDS
;******************************************************
         END