在linux下C语言实现对输入事件的监听

在windows下有个键盘测试函数，int kbhit(void)。使用该函数需要包含头文件conio.h。执行时，kbhit测试是否有键盘按键按下，若有则返回非零值，否则返回零。

在Unix/Linux下，并没有提供这个函数。在linux下开发控制台程序时，有时会遇到检测键盘是否有被按下的情况，这时就需要自己编写kbhit()实现的程序了。

 #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;
 }