135 lines
2.4 KiB
NASM
135 lines
2.4 KiB
NASM
; 实验八-5: 文件复制程序
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; 功能: 使用DOS功能号实现文件复制
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; 说明: 读取源文件内容，写入目标文件
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DATAS SEGMENT
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SRC_FILE DB 'source.txt', 0 ; 源文件名
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DST_FILE DB 'dest.txt', 0 ; 目标文件名
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HANDLE DW ? ; 文件句柄
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BUFFER DB 512 DUP(?) ; 读写缓冲区 (512字节)
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ERR_OPEN DB 'Cannot open source file!', 0DH, 0AH, '$'
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ERR_READ DB 'Read error!', 0DH, 0AH, '$'
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ERR_WRITE DB 'Write error!', 0DH, 0AH, '$'
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OK_MSG DB 'File copied successfully!', 0DH, 0AH, '$'
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DATAS ENDS
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STACKS SEGMENT
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DB 64 DUP(?)
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STACKS ENDS
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CODES SEGMENT
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ASSUME CS:CODES, DS:DATAS, SS:STACKS
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START:
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MOV AX, DATAS
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MOV DS, AX
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; 打开源文件 (功能号3DH，只读模式)
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LEA DX, SRC_FILE
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MOV AH, 3DH
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MOV AL, 00H
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INT 21H
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JNC OPEN_OK
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LEA DX, ERR_OPEN
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MOV AH, 09H
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INT 21H
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JMP PROGRAM_END
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OPEN_OK:
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MOV HANDLE, AX
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; 创建目标文件 (功能号3CH)
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LEA DX, DST_FILE
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MOV AH, 3CH
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MOV AL, 00H
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INT 21H
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MOV BX, AX ; 保存目标文件句柄到BX
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JNC CREATE_OK
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; 关闭源文件
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MOV AH, 3EH
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INT 21H
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LEA DX, ERR_OPEN
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MOV AH, 09H
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INT 21H
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JMP PROGRAM_END
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CREATE_OK:
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; 读取源文件循环
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COPY_LOOP:
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; 读取源文件 (功能号3FH)
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MOV CX, 512
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LEA DX, BUFFER
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MOV AH, 3FH
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INT 21H
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; 检查读取是否成功
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JNC READ_OK
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; 关闭两个文件
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PUSH BX
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MOV AH, 3EH
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MOV BX, HANDLE
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INT 21H
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POP BX
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MOV AH, 3EH
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INT 21H
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LEA DX, ERR_READ
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MOV AH, 09H
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INT 21H
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JMP PROGRAM_END
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READ_OK:
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; 检查是否到达文件末尾 (AX=0表示EOF)
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CMP AX, 0
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JE COPY_COMPLETE
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; 写入目标文件 (功能号40H)
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; BX中已经是目标文件句柄
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MOV CX, AX ; CX = 实际读取的字节数
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MOV AH, 40H
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INT 21H
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; 检查写入是否成功
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JNC WRITE_OK
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; 关闭两个文件
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PUSH BX
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MOV AH, 3EH
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MOV BX, HANDLE
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INT 21H
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POP BX
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MOV AH, 3EH
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INT 21H
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LEA DX, ERR_WRITE
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MOV AH, 09H
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INT 21H
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JMP PROGRAM_END
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WRITE_OK:
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JMP COPY_LOOP
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COPY_COMPLETE:
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; 关闭源文件
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MOV AH, 3EH
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MOV BX, HANDLE
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INT 21H
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; 关闭目标文件
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MOV AH, 3EH
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INT 21H
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LEA DX, OK_MSG
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MOV AH, 09H
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INT 21H
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PROGRAM_END:
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MOV AH, 4CH
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INT 21H
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CODES ENDS
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END START |