实验一 命令解释程序的编写

一、目的和要求

1. 实验目的

（1）掌握命令解释程序的原理；

（2）*掌握简单的DOS调用方法；

（3）掌握C语言编程初步。

2．实验要求

编写类似于DOS，UNIX的命令行解释程序

（1）自行定义系统提示符

（2）自定义命令集（8-10个）

（3）用户输入HELP以查找命令的帮助

（4）列出命令的功能，区分内部还是外部命令

（5）用户输入QUIT退出

（6）内部命令有dir, cd, md, rd, cls, date, time, ren, copy等。

二、实验内容

根据教师指定的实验课题，完成设计、编码、测试工作。

三、实验环境

1．PC微机

2．Windows 操作系统

3．C/C++程序开发集成环境

四、实验原理及核心算法参考程序段

1. 命令解释程序的原理：

命令解释程序的主要功能是：

1)        接受和执行一条用户从键盘输入的命令，它通常保存一张命令名字（动词）表，其中记录着所有操作命令及其处理程序的入口地址或有关信息。

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

#define MAXLINE 1000
#define N 100
#define Head1 "Microsoft Windows XP [版本 5.1.2600]"
#define Head2 "<C> 版权所有 1985-2001 Microsoft Corp."
#define Head3 "C:\Documents and Settings\Administrator>"


void FakeTopTitle()
{    
    printf(Head1"
");
    printf(Head2"
");
    printf("
");
    //printf(Head3);
}

/*
void ReadFromDocument()
{
    FILE *fp;
    char arr[MAXLINE+1];
    printf("
");
    if ((fp = fopen ("CommandLine.txt", "r")) == NULL)
    {
         perror ("File open error!
");
         exit (1);
    }
    while ((fgets (arr, MAXLINE, fp)) != NULL)
    {
        fputs (arr, stderr);
    }
    printf("

");
    printf(Head3);
}    
*/
/*
void Test()
{
    char s[200][200] = {0};
    int i=0;
    FILE *fp;
    fp = fopen("CommandLine.txt","r");
    printf("
");
    for(i=0;i<200;i++)
    {
        fscanf(fp,"%s",s[i]);
        printf("%s
",s[i]);
    }
}
*/

int main()
{
    int i;
    char a[100][100]={"assoc","attrib","break","bootcfg","cacls","call","cd","chcp","chdir",
                    "chkdsk","chkntfs","cls","cmd","color","comp","compact","convert",
                    "copy","date","del","dir","diskcomp","diskcopy","diskpart","doskey",
                    "driverquery","echo","endlocal","erase","eventquery","fc",
                    "find","for","format","fsutil","ftype","goto","gpresult","help","if",
                    "label","md","mkdir","mode","more","move","openfiles","pagefileconfig",
                    "path","pause","popd","print","prompt","pushd","rd","recover","rem",
                    "ren","rename","replace","rmdir","set","setlocal","sc","schtasks",
                    "shift","shutdown","sort","start","subst","systeminfo","tasklist",
                    "taskkill","time","title","tree","type","ver","verify","vol","xcopy",
                    "wmic"};
    char b[100];
    FakeTopTitle();
loop1:printf(Head3);
      gets(b);
    for(i=0;i<N;i++)
    {
            if(strcmp(a[i],b)==0)
            {
                system(b);
                printf("
");
                printf(Head3);
                getchar();
            }
            else
            {
                break;
            }
            if(strcmp(b,"exit")==0)
            {
                exit(0);
                getchar();
            }
    }
    system(b);
    goto loop1;
    getchar();
    return 0;
}