BIOS和DOS中断大全_DOS中断_02目录控制功能

2、目录控制功能(Directory-Control Function)

接上文: BIOS和DOS中断大全列程_DOS中断_01字符调用类

INT 21h 中断

目录
39H —创建目录
3AH —删除目录
3BH —设置当前目录
47H —读取当前目录

 

(1)、功能39H


功能描述：用指定的驱动器和路径创建一个新目录
入口参数：

AH＝39H
DS:DX＝指定路径的字符串地址(以0为字符串的结束标志)
出口参数：CF＝0——创建成功，否则，AX＝错误号(03H或05H)，其含义见错误代码表

例程：

   1:  assume cs:code
   2:   
   3:  data segment
   4:      path db 'c:/123', 0
   5:      successstr db 'create path success!$', 0
   6:      failstr db 'create path fail!$', 0
   7:  data ends
   8:   
   9:  code segment
  10:  start:
  11:      mov ax, data
  12:      mov ds, ax
  13:      
  14:      lea dx, path
  15:      xor ax, ax
  16:      mov ah, 39h
  17:      int 21h 
  18:      jc fail
  19:  success:
  20:      lea dx, successstr
  21:      mov ah, 09h
  22:      int 21h
  23:      jmp codeEnd
  24:  fail:
  25:      lea dx, failstr
  26:      mov ah, 09h
  27:      int 21h
  28:  codeEnd:    
  29:      mov ax, 4c00h
  30:      int 21h
  31:  code ends
  32:  end start

(2)、功能3AH


功能描述：删除指定的驱动器和路径的目录
入口参数：

AH＝3AH
DS:DX＝指定路径的字符串地址(以0为字符串的结束标志)

出口参数：CF＝0——删除成功，否则，AX＝错误号(03H或05H)，其含义见错误代码表

例程:

   1:  assume cs:code
   2:   
   3:  data segment
   4:      path db 'c:/123', 0
   5:      successstr db 'delete path success!$', 0
   6:      failstr db 'delete path fail!$', 0
   7:  data ends
   8:   
   9:  code segment
  10:  start:
  11:      mov ax, data
  12:      mov ds, ax
  13:      
  14:      lea dx, path
  15:      xor ax, ax
  16:      mov ah, 3Ah
  17:      int 21h 
  18:      jc fail
  19:  success:
  20:      lea dx, successstr
  21:      mov ah, 09h
  22:      int 21h
  23:      jmp codeEnd
  24:  fail:
  25:      lea dx, failstr
  26:      mov ah, 09h
  27:      int 21h
  28:  codeEnd:    
  29:      mov ax, 4c00h
  30:      int 21h
  31:  code ends
  32:  end start

(3)、功能3BH


功能描述：用指定的驱动器和路径设置为当前目录
入口参数：

AH＝3BH
DS:DX＝指定路径的字符串地址(以0为字符串的结束标志)

出口参数：CF＝0——设置成功，否则，AX＝错误号(03H)，其含义见错误代码表

例程:

   1:  assume cs:code
   2:   
   3:  data segment
   4:      path db 'c:/123', 0
   5:      failstr db 'fetch current path fail!$', 0
   6:      result db 255 dup(0)
   7:  data ends
   8:   
   9:  code segment
  10:  print:
  11:      push bx
  12:      push ax
  13:      push dx
  14:  printStart:
  15:      cmp byte ptr ds:[bx], 0
  16:      jz printEnd
  17:      mov dl, ds:[bx]
  18:      call printChar
  19:      inc bx
  20:      jmp printStart
  21:  printEnd:
  22:      pop dx
  23:      pop ax
  24:      pop bx
  25:      ret
  26:      
  27:  ; input - dl 
  28:  printChar:
  29:      mov ah, 02h
  30:      int 21h
  31:      ret
  32:      
  33:  start:
  34:      mov ax, data
  35:      mov ds, ax
  36:      
  37:      mov ah, 3bh
  38:      lea dx, path
  39:      
  40:      int 21h
  41:      
  42:      jc fail
  43:      
  44:      xor ax, ax
  45:      xor dx, dx
  46:      mov ah, 47h
  47:      lea si, result
  48:      
  49:      int 21h 
  50:      jc fail
  51:  success:
  52:      mov bx, si
  53:      call print
  54:      jmp codeEnd
  55:  fail:
  56:      lea dx, failstr
  57:      mov ah, 09h
  58:      int 21h
  59:  codeEnd:    
  60:      mov ax, 4c00h
  61:      int 21h
  62:  code ends
  63:  end start

(4)、功能47H


功能描述：取当前目录的完全路径字符串
入口参数：

AH＝47H
DL＝驱动器号(0=缺省，1＝A，…)
DS:SI＝存放当前目录字符串的地址

出口参数：CF＝0——读取成功，否则，AX＝错误号(0FH)，其含义见错误代码表

例程: 请参看 (3)、功能3BH

posted @ 2013-07-23 00:15  Ares_  阅读(483)  评论(0)  编辑  收藏  举报