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oscmd.asm
资源名称：DOS系统的源代码.rar [点击查看]
上传用户：xiaoan1112
上传日期：2013-04-11
资源大小：19621k
文件大小：4k
源码类别：
操作系统开发
开发平台：
Visual C++
- TITLE OSCMD - Operating System Command line access
- ;***
- ;OSCMD.ASM - Operating System command line access
- ;
- ; Copyright <C> 1987, Microsoft Corporation
- ;
- ;Purpose:
- ; This module contains routines to access and manipulate the
- ; command line. This is used by statements such as OPEN "PIPE:",
- ; RUN/CHAIN/SHELL/COMMAND$.
- ;
- ;******************************************************************************
- INCLUDE switch.inc
- INCLUDE rmacros.inc
- ;
- ; Code Segments
- ;
- USESEG <OS_TEXT> ;Operating System
- USESEG <NH_TEXT> ;Near Heap
- USESEG <RT_TEXT> ;Runtime Core
- ;
- ; Data Segments
- ;
- USESEG <_DATA>
- USESEG <_BSS> ;runtime data (uninitialized)
- INCLUDE seg.inc
- INCLUDE ascii.inc
- INCLUDE idmac.inc
- SUBTTL Code Externals
- PAGE
- sBegin NH_TEXT
- externNP B$STALCTMPCPY
- sEnd NH_TEXT
- sBegin RT_TEXT
- sEnd RT_TEXT
- SUBTTL Runtime data definitions for BASIC Operating System
- PAGE
- sBegin _BSS
- externW __acmdln ;command line pointer
- externB b$Buf1 ;defined in GWINI.ASM
- sEnd _BSS
- SUBTTL Runtime Operating System Initialization
- PAGE
- assumes CS,OS_TEXT
- sBegin OS_TEXT
- ;***
- ;B$Arg0Skip - Skip past the program name on command line.
- ;Purpose:
- ; The DOS 5 command line now has the program name as the
- ; first element of the command line string. This element
- ; needs to be skipped for compatability in things like
- ; Command$, RUN and CHAIN.
- ;
- ; NOTE: this routine works for KANJI characters because all of
- ; the items that we are testing (" ", 0, ASCCR) are less than
- ; any possible second byte of a Kanji Character.
- ;
- ;Entry:
- ; DS:SI - points to command line
- ;Exit:
- ; DS:AX - points to command line past program name
- ;Modifies:
- ; None.
- ;Exceptions:
- ; None.
- ;*****************************************************************************
- ;***
- ;B$CmdCopy - copy DOS command line from DS:SI to ES:DI
- ;Purpose:
- ; Copies the MSDOS command line into a buffer. This routine is
- ; called by COMMAND$, CHAIN, and RUN.
- ;Entry:
- ; DS:SI - points to command line
- ; ES:DI - points to place to put command line
- ; For DOS 3, this is limited to 128 bytes, but OS/2 could
- ; could have up to 256 bytes.
- ;Exit:
- ; BX - count of chars copied
- ; Command line is copied into ES:DI
- ;Modifies:
- ; None.
- ;Exceptions:
- ; None.
- ;***************************************************************************
- cProc B$CmdCopy,<PUBLIC,NEAR>,<SI,DI>
- cBegin
- XOR BX,BX ; initialize character count
- CMD_IGNORE:
- LODSB ; fetch next char from command line
- CMP AL," "
- JE CMD_IGNORE ; ignore leading blanks
- CMD_LOOP:
- OR AL,AL ; 0 terminates command string
- JZ CMD_TERM
- CMP AL,ASCCR
- JE CMD_TERM ; CR terminates command string
- CMP AL,"a"
- JB CMD_COPY ; just copy if not lower case
- CMP AL,"z"
- JA CMD_COPY ; just copy if not lower case
- XOR AL,20H ; convert lower case to upper case
- CMD_COPY:
- STOSB ; copy char into temporary buffer
- INC BX ; increment char count
- DbAssertRelB BH,E,0,OS_TEXT,<Buffer overflow in B$CmdCopy>
- LODSB ; fetch next char from command line
- JMP SHORT CMD_LOOP ; repeat until end of command string
- CMD_TERM:
- cEnd
- ;***
- ;B$FCMD - return command line
- ;Purpose:
- ; Implement COMMAND$ function by returning a string containimg
- ; the MS-DOS command line.
- ;
- ;Inputs:
- ; None.
- ;Outputs:
- ; AX = ptr to string desc for temp with command line.
- ;Modifies:
- ; None.
- ;Exceptions:
- ; None.
- ;******************************************************************************
- externNP B$FrameAFE
- cProc B$FCMD,<PUBLIC,FAR>
- cBegin <nogen>
- jmp B$FrameAFE
- cEnd <nogen>
- sEnd OS_TEXT
- END
