【C++】linux下監聽鍵盤事件（按鍵后非阻塞讀取，不用Enter）

#include <termio.h>
#include <stdio.h>

int scanKeyboard()
{
    int input;
    struct termios new_settings;
    struct termios stored_settings;
    tcgetattr(0,&stored_settings);
    new_settings = stored_settings;
    new_settings.c_lflag &= (~ICANON);
    new_settings.c_cc[VTIME] = 0;
    tcgetattr(0,&stored_settings);
    new_settings.c_cc[VMIN] = 1;
    tcsetattr(0,TCSANOW,&new_settings);
     
    in = getchar();
     
    tcsetattr(0,TCSANOW,&stored_settings);
    return input;
}

//返回該鍵的ASCII碼值，不需回車

 

解析：

ICANON
Enable canonical mode. This enables the special characters EOF, EOL, EOL2, ERASE, KILL, LNEXT, REPRINT, STATUS, and WERASE, and buffers by lines.

可以看出 ICNAON 標志位啟用了整行緩存。

所以，new_settings.c_lflag &= (~ICANON);這句屏蔽整行緩存。那就只能單個了。

 

通過tcsetattr函數設置terminal的屬性來控制需不需要回車來結束輸入。

注：通過while循環讀取鍵盤效率很低，參考使用異步事件或者多線程技術。單線程為阻塞式的

　　

 

【原文】https://blog.csdn.net/alangdangjia/article/details/27697721

在windows下有個鍵盤測試函數，int kbhit(void)。使用該函數需要包含頭文件conio.h。執行時，kbhit測試是否有鍵盤按鍵按下，若有則返回非零值，否則返回零。

在Unix/Linux下，並沒有提供這個函數。在linux下開發控制台程序時，有時會遇到檢測鍵盤是否有被按下的情況，這時就需要自己編寫 kbhit() 實現的程序了。

#include <stdio.h>
#include <termios.h>
 
static struct termios initial_settings, new_settings;
static int peek_character = -1;

void init_keyboard(void);
void close_keyboard(void);
int kbhit(void);
int readch(void); 

void init_keyboard()
{
	tcgetattr(0,&initial_settings);
	new_settings = initial_settings;
	new_settings.c_lflag |= ICANON;
	new_settings.c_lflag |= ECHO;
	new_settings.c_lflag |= ISIG;
	new_settings.c_cc[VMIN] = 1;
	new_settings.c_cc[VTIME] = 0;
	tcsetattr(0, TCSANOW, &new_settings);
}
 
void close_keyboard()
{
	tcsetattr(0, TCSANOW, &initial_settings);
}
 
int kbhit()
{
	unsigned char ch;
	int nread;
 
	if (peek_character != -1) return 1;
	new_settings.c_cc[VMIN]=0;
	tcsetattr(0, TCSANOW, &new_settings);
	nread = read(0,&ch,1);
	new_settings.c_cc[VMIN]=1;
	tcsetattr(0, TCSANOW, &new_settings);
	if(nread == 1) 
	{
		peek_character = ch;
		return 1;
	}
	return 0;
}
 
int readch()
{
	char ch;
 
	if(peek_character != -1) 
	{
		ch = peek_character;
		peek_character = -1;
		return ch;
	}
	read(0,&ch,1);
	return ch;
}
 
int main()
{
	init_keyboard();
	while(1)
	{
		kbhit();
		printf("\n%d\n", readch());
	}
	close_keyboard();
	return 0;
}

　

linux termios 結構：

https://blog.csdn.net/querdaizhi/article/details/7436722