《Linux程序设计 第四版》之第五章的练习题

1、P168

一个完整的终端输出选择菜单的程序。

#include
#include
#include
#include
#include
#include    
#include  
#include  
#include  
int getchoice(char* ,const char** ,FILE*,FILE*);

static FILE* output_stream=(FILE*)0;

char* opt[]=
{
	"a -- add a new record",
	"d -- delete a new record",
	"q -- quit",
	NULL
};

int char_to_terminal(int char_to_write)
{
	if (output_stream)putc(char_to_write,output_stream);
	return 0;


}

int getchoice(char* words,const char** opt,FILE* in,FILE* out)
{
	int choice;
	char** tmp_opt=opt;

	int screenrow=4;
	int screencol=10;
	char *cursor,*clear;
	output_stream=out;
	while(1)
	{

	//将输出修改成清屏，然后左上角输出、
	screenrow=4;
	setupterm(NULL,fileno(out),(int *)0);
	cursor=tigetstr("cup");	
	clear=tigetstr("clear");	


	tputs(clear,1,(int *)char_to_terminal);
	tputs(tparm(cursor,screenrow,screencol),1,char_to_terminal);
	fprintf(out,"Choice:\n");

	screenrow+=2;

	while(*tmp_opt)
	{
		tputs(tparm(cursor,screenrow,screencol),1,char_to_terminal);
		fprintf(out,"%s\n", *tmp_opt );
		tmp_opt++;
		screenrow++;

	}
	fprintf(out,"\n" );

	do
	{
	fflush(out);
	choice=fgetc(in);
	}while(choice=='\n' || choice=='\r');

	tmp_opt=opt;

	while(*tmp_opt)
	{	
		if (choice==*tmp_opt[0])
		{
			return choice;

		}
		else{
			tmp_opt++;
		}

	}
	tputs(tparm(cursor,screenrow,screencol),1,char_to_terminal);
	fprintf(stderr,"Incorrect choice,select again\n");
	}

}



int main(int argc,char** argv)
{
int choice=0;
FILE* in=fopen("/dev/tty","r");
FILE* out=fopen("/dev/tty","w");

if(!in||!out)
{
	fprintf(stderr, "%s\n", "Unable to open /dev/tty \n");
	exit(1);

}


struct termios tmp_tos,back_tos;
tcgetattr(fileno(in),&tmp_tos);
back_tos=tmp_tos;

tmp_tos.c_lflag &= ~ICANON;
tmp_tos.c_lflag &= ~ECHO;
tmp_tos.c_lflag &= ~ISIG;
tmp_tos.c_cc[VMIN] = 1;
tmp_tos.c_cc[VTIME] = 0;

if (tcsetattr(fileno(in),TCSANOW,&tmp_tos)!=0)
{
	fprintf(stderr, "%s\n", "Unable to set /dev/tty \n");
}

while(choice!='q')
{
	choice=getchoice("Please select an action",opt,in,out);
	fprintf(out,"You have choose: %c \n", choice);
	sleep(1);

}
tcsetattr(fileno(in),TCSANOW,&back_tos);
return 0;
}

1、P171

一个检测击键事件的程序。

#include
#include
#include
#include
#include
#include    
#include  
#include  
#include  

static struct  termios initsetting,newsetting;
void close_keybord();
void init_keybord();
int readch();
int kbhit();

int main(int argc,char** argv)
{
int choice=0;
init_keybord();

while(choice!='q')
{
	printf("looping\n");
	sleep(1);
	if (choice=kbhit())
	{
	choice=readch();
	printf("You have key: %c \n", choice);
	
	}
	

}

close_keybord();
return 0;
}


void close_keybord()
{
tcsetattr(0,TCSANOW,&initsetting);
}

void init_keybord()
{
tcgetattr(0,&initsetting);
newsetting=initsetting;
newsetting.c_lflag &= ~ICANON;
newsetting.c_lflag &= ~ECHO;
newsetting.c_lflag &= ~ISIG;
newsetting.c_cc[VMIN] = 1;
newsetting.c_cc[VTIME] = 0;
tcsetattr(0,TCSANOW,&newsetting);
}

int readch(){

}

int kbhit(){

char ch;
int nread;
newsetting.c_cc[VMIN] = 0;
tcsetattr(0,TCSANOW,&newsetting);
nread=read(0,&ch,1);
newsetting.c_cc[VMIN] = 1;
tcsetattr(0,TCSANOW,&newsetting);

if (nread==1)
{
	return ch;
}
return 0;
}