我已经规范了系统代码风格，类似于按照linux分包，把各部分功能区分开了

Antz系统更新地址

Linux内核源码分析地址

Github项目地址

在之前的任务中，我们已经通过直接操作显卡驱动完成了简单的图形化。

需要了解之前的部分：

直接操作显卡请参考day03

简单图形化的实现请参考day09

键盘按键中断响应请参考day10

Makefile

项目目录

一 . 如何实现命令缓存

在之前已经完成了键盘的响应工作，但这种响应却是有很大的问题，比如说对于一次按键的两次中断处理。后来我把两种中断都加入了响应判断中，这样就不会有之前第10天所提到的bug了。

* 在替换函数中完成识别。修改如下

char* replace_char(char s[40]){

	char *chr = "$" ;

	if((strcmp(s,"1E")==0)||(strcmp(s,"9E")==0)){

			chr = "a" ;

	}else if((strcmp(s,"30")==0)||(strcmp(s,"B0")==0)){

			chr = "b" ;

	}

	... // 省略

	return chr ;

* 这里是一些功能按键的识别修改

    // Enter  -> 回车键 响应之前缓存的命令 换行

	if((strcmp(s,"1C")==0)||(strcmp(s,"9C")==0)){

			action_command(binfo);  //响应命令

			write_x = 58 ;   //下面是换行

			write_y += 19 ;

			putfonts8_asc(binfo->vram, binfo->scrnx, 4, write_y, COL8_FFFFFF, "AntzOS>");

	}

    // F1 -> 终端刷新  类似于clear命令

	else if((strcmp(s,"3B")==0)||(strcmp(s,"BB")==0)){  //关于F1的响应中断

			sprintf(command,"%s","");  // 命令缓存清空

			flag = 0 ;  // 按键模式回复默认，这个看第10天，本质目的是为了处理一次按键的两次终端

			new_pe(binfo);  // 通过操作显存直接刷新当前终端

			putfonts8_asc(binfo->vram, binfo->scrnx, 4, write_y, COL8_FFFFFF, "AntzOS>");

	}

	//  Backspace -> 删格键

	else if(strcmp(s,"0E")==0){

			// 回退

			write_x -= 8 ;

			boxfill8(binfo->vram, binfo->scrnx , COL8_000000,  write_x,     write_y,     write_x+19, write_y+19);

			if(write_x<=58){

				write_x = 146 ;

				write_y -= 19 ;

			}

	}

这些就是按键识别上目前修改的内容了。

接下来我们要添加一个功能，在每次按键之后，不但在屏幕上显示这个键，而且将他缓存在缓冲区，在下次回车的时候进行识别，并清空。

先来看一个简单的demo

// command数组就是命令缓存区

char  command[100]  = "";

void add_command(char *s)  {

    sprintf(command,"%s%s",command,s);

}

void action_command(){

    // 响应

}

二 . 实现

command就是一个命令缓存数组，每次按键之后调用add_command()命令将这次的按键保存。

sprintf()这个函数是字符串格式化命令，主要功能是把格式化的数据写入某个字符串中。sprintf 是个变参函数。使用sprintf 对于写入buffer的字符数是没有限制的，这就存在了buffer溢出的可能性。

我们使用sprintf函数直接在command后面添加了s字符。

那么在下次按下Enter的时候，我们只需要调用action_command,并且在里面识别是什么命令，然后做出合适的响应即可。

来看看完整的命令缓冲区实现。

// 指令缓存，但是因为中断响应的时间问题，终端输入速度要非常慢

char  command[100]  = "";

void add_command(char *s)  {

    if(strcmp(s," ")==0){

	    sprintf(command,"%s%s",command,"");

    }else if(strcmp(s,"$")){

		//忽略这种错误输入

	}else {

	    sprintf(command,"%s%s",command,s);

	}

}

void action_command(struct BOOTINFO *binfo){

		// action command 响应命令

		// ls命令

		// data命令

		if(strcmp(command,"data")==0){

			// get new data;

			write_y += 19 ;

			putfonts8_asc(binfo->vram, binfo->scrnx, 4, write_y, COL8_FFFFFF, "AntzOS in 2018");

		}else if(strcmp(command,"cls")==0){

			flag = 0 ;

			new_pe(binfo);

		}else if(strcmp(command,"version")==0){

			write_y += 19 ;

			putfonts8_asc(binfo->vram, binfo->scrnx, 4, write_y, COL8_FFFFFF, "Antz.version.1.1");

		}else if(strcmp(command,"help")==0){

			// help内容过多，显示在图形化界面区域

		}else if(sizeof(command)>=1){

				write_y += 19 ;

				putfonts8_asc(binfo->vram, binfo->scrnx, 4, write_y, COL8_FFFFFF, "Not Found");

		}

		// 命令缓存清除

		sprintf(command,"%s","");

}

现在使用Makefile来生成这个支持命令的img镜像。

    make img

使用虚拟机打开镜像，结果如下

终端主要代码如下：

int write_x = 55 ;

int write_y = 57 ;

char* replace_char(char s[40]){

	char *chr = "$" ;

	if((strcmp(s,"1E")==0)||(strcmp(s,"9E")==0)){

			chr = "a" ;

	}else if((strcmp(s,"30")==0)||(strcmp(s,"B0")==0)){

			chr = "b" ;

	}else if((strcmp(s,"2E")==0)||(strcmp(s,"AE")==0)){

			chr = "c" ;

	}else if((strcmp(s,"20")==0)||(strcmp(s,"A0")==0)){

			chr = "d" ;

	}else if((strcmp(s,"12")==0)||(strcmp(s,"92")==0)){

			chr = "e" ;

	}else if((strcmp(s,"21")==0)||(strcmp(s,"A1")==0)){

			chr = "f" ;

	}else if((strcmp(s,"22")==0)||(strcmp(s,"A2")==0)){

			chr = "g" ;

	}else if((strcmp(s,"23")==0)||(strcmp(s,"A3")==0)){

			chr = "h" ;

	}else if((strcmp(s,"17")==0)||(strcmp(s,"97")==0)){

		chr = "i" ;

	}else if((strcmp(s,"24")==0)||(strcmp(s,"A4")==0)){

		chr = "j" ;

	}else if((strcmp(s,"25")==0)||(strcmp(s,"A5")==0)){

		chr = "k" ;

	}else if((strcmp(s,"26")==0)||(strcmp(s,"A6")==0)){

		chr = "l" ;

	}else if((strcmp(s,"32")==0)||(strcmp(s,"B2")==0)){

		chr = "m" ;

	}else if((strcmp(s,"31")==0)||(strcmp(s,"B1")==0)){

		chr = "n" ;

	}else if((strcmp(s,"18")==0)||(strcmp(s,"98")==0)){

		chr = "o" ;

	}else if((strcmp(s,"19")==0)||(strcmp(s,"99")==0)){

		chr = "p" ;

	}else if((strcmp(s,"10")==0)||(strcmp(s,"90")==0)){

		chr = "q" ;

	}else if((strcmp(s,"13")==0)||(strcmp(s,"93")==0)){

		chr = "r" ;

	}else if((strcmp(s,"1F")==0)||(strcmp(s,"9F")==0)){

		chr = "s" ;

	}else if((strcmp(s,"14")==0)||(strcmp(s,"94")==0)){

		chr = "t" ;

	}else if((strcmp(s,"16")==0)||(strcmp(s,"96")==0)){

		chr = "u" ;

	}else if((strcmp(s,"2F")==0)||(strcmp(s,"AF")==0)){

		chr = "v" ;

	}else if((strcmp(s,"11")==0)||(strcmp(s,"91")==0)){

		chr = "w" ;

	}else if((strcmp(s,"2D")==0)||(strcmp(s,"AD")==0)){

		chr = "x" ;

	}else if((strcmp(s,"15")==0)||(strcmp(s,"95")==0)){

		chr = "y" ;

	}else if((strcmp(s,"2C")==0)||(strcmp(s,"AC")==0)){

		chr = "z" ;

	}else if((strcmp(s,"39")==0)||(strcmp(s,"B9")==0)){

		chr = " " ;

	}

	return chr ;

}

int flag = 1 ;

// 指令缓存，但是因为中断响应的时间问题，终端输入速度要非常慢

char  command[100]  = "";

void add_command(char *s)  {

/*

if(strcmp(s," ")==0){

	sprintf(command,"%s%s",command,"");

}else	if(strcmp(s,"$")){

				//忽略这种错误输入

		}else {

	}

*/

		sprintf(command,"%s%s",command,s);

}

void action_command(struct BOOTINFO *binfo){

		// action command

		// ls

		// data

		if(strcmp(command,"data")==0){

			// get new data;

			write_y += 19 ;

			putfonts8_asc(binfo->vram, binfo->scrnx, 4, write_y, COL8_FFFFFF, "AntzOS in 2018");

		}else if(strcmp(command,"cls")==0){

			flag = 0 ;

			new_pe(binfo);

		}else if(strcmp(command,"version")==0){

			write_y += 19 ;

			putfonts8_asc(binfo->vram, binfo->scrnx, 4, write_y, COL8_FFFFFF, "Antz.version.1.1");

		}else if(strcmp(command,"help")==0){

			// help内容过多，显示在图形化界面区域

		}else if(sizeof(command)>=1){

				write_y += 19 ;

				putfonts8_asc(binfo->vram, binfo->scrnx, 4, write_y, COL8_FFFFFF, "Not Found");

		}

		// 命令缓存清除

		sprintf(command,"%s","");

}

void key(struct BOOTINFO *binfo,char s[40]){

	if((strcmp(s,"1C")==0)||(strcmp(s,"9C")==0)){

			action_command(binfo);

			write_x = 58 ;

			write_y += 19 ;

			putfonts8_asc(binfo->vram, binfo->scrnx, 4, write_y, COL8_FFFFFF, "AntzOS>");

	}else if((strcmp(s,"3B")==0)||(strcmp(s,"BB")==0)){  //关于F1的响应中断

			sprintf(command,"%s","");

			flag = 0 ;

			new_pe(binfo);

			putfonts8_asc(binfo->vram, binfo->scrnx, 4, write_y, COL8_FFFFFF, "AntzOS>");

	}else if(strcmp(s,"0E")==0){

			// 回退

			write_x -= 8 ;

			boxfill8(binfo->vram, binfo->scrnx , COL8_000000,  write_x,     write_y,     write_x+19, write_y+19);

			if(write_x<=58){

				write_x = 146 ;

				write_y -= 19 ;

			}

	}else {

			//putfonts8_asc(binfo->vram, binfo->scrnx,  write_x,  write_y, COL8_FFFFFF, s);

			putfonts8_asc(binfo->vram, binfo->scrnx,  write_x,  write_y, COL8_FFFFFF, replace_char(s));

			add_command(replace_char(s));

			write_x += 8 ;

			// 添加响应区

			//清除

			//boxfill8(binfo->vram, binfo->scrnx, COL8_008400 , 300	,240	,310	,250);

			//打印字符 Only use debug

			//putfonts8_asc(binfo->vram, binfo->scrnx,  300,  240 ,COL8_000000, s) ;

	}

	if(write_x>148){

		write_x = 58 ;

		write_y += 19 ;

		//putfonts8_asc(binfo->vram, binfo->scrnx, 4, 57, COL8_FFFFFF, "AntzOS>");

	}

	if(write_y>180){

 		new_pe(binfo);

		putfonts8_asc(binfo->vram, binfo->scrnx, 4, write_y, COL8_FFFFFF, "AntzOS>");

	}

}

void main(void)

{

	struct BOOTINFO *binfo = (struct BOOTINFO *) ADR_BOOTINFO;

	char s[40], mcursor[256], keybuf[32], mousebuf[128];

	int mx, my, i;

	init_gdtidt();

	init_pic();

	io_sti(); /* PIC的初始化已经完成*/

	fifo8_init(&keyfifo, 32, keybuf);

	fifo8_init(&mousefifo, 128, mousebuf);

	io_out8(PIC0_IMR, 0xf9); /* 开放PIC1和键盘中断(11111001) */

	io_out8(PIC1_IMR, 0xef); /* 开放鼠标中断(11101111) */

	init_keyboard();

	init_palette();

	init_screen8(binfo->vram, binfo->scrnx, binfo->scrny);

	putfonts8_asc(binfo->vram, binfo->scrnx,  0,  0, COL8_FFFFFF, "Terminal-Antz");

	putfonts8_asc(binfo->vram, binfo->scrnx,  0,  0, COL8_000000, "Terminal-Antz");

	putfonts8_asc(binfo->vram, binfo->scrnx,  107,  0, COL8_000000, "|-|o|x|");

	putfonts8_asc(binfo->vram, binfo->scrnx, 4, 19, COL8_FFFFFF, "AntzOS> SayHello()");

	putfonts8_asc(binfo->vram, binfo->scrnx, 4, 38, COL8_FFFFFF, "Hello My AntzOs.");

	putfonts8_asc(binfo->vram, binfo->scrnx, 4, 57, COL8_FFFFFF, "AntzOS>_");

	for (;;) {

		io_cli();

		if (fifo8_status(&keyfifo) + fifo8_status(&mousefifo) == 0) {

			io_stihlt();

		} else {

			if (fifo8_status(&keyfifo) != 0) {

				i = fifo8_get(&keyfifo);

				io_sti();

				sprintf(s, "%02X", i);

				if (flag){

					key(binfo,s);

				}

				if(flag==1){

					flag = 0 ;

				}else {

					flag = 1 ;

				}

			}

		}

	}

}

void new_pe(struct BOOTINFO *binfo){

	write_x = 58 ;

	write_y = 19 ;

	// 右边并没有保存

	init_screen8(binfo->vram, binfo->scrnx, binfo->scrny);

	putfonts8_asc(binfo->vram, binfo->scrnx,  0,  0, COL8_FFFFFF, "Terminal-Antz");

	putfonts8_asc(binfo->vram, binfo->scrnx,  0,  0, COL8_000000, "Terminal-Antz");

	putfonts8_asc(binfo->vram, binfo->scrnx,  107,  0, COL8_000000, "|-|o|x|");

	// 此处保留此输出，交给调用者自己

	//	putfonts8_asc(binfo->vram, binfo->scrnx, 4, write_y, COL8_FFFFFF, "AntzOS>");

}