问题描述
目前,我正在以下列方式读取串行端口的CTS和DSR信号:
Currently, I'm reading the CTS and DSR signals of a serial port in the following way:
bool get_cts(int fd) {
int s;
ioctl(fd, TIOCMGET, &s);
return (s & TIOCM_CTS) != 0;
}
现在我想等待 get_cts )
返回true。一个简单的循环不是我认为最好的解决方案(因为它是非常资源密集型)。
Now I'd like to wait until get_cts()
returns true. A simple loop isn't the best solution I think (as it's extremely resource-intensive).
void wait_cts(int fd) {
while(1) {
if(get_cts(fd)) {
return;
}
}
}
C或C ++在Linux? (我不能使用任何硬件流控制,因为我根本不需要串行数据线。)
Is there any better solution using C or C++ on Linux? (I cannot use any hardware flow control as I don't need the serial data lines at all.)
推荐答案
ioctl TIOCMIWAIT
会阻塞,直到给定的一组信号发生变化。
There is the ioctl TIOCMIWAIT
which blocks until a given set of signals change.
很遗憾这个ioctl没有记录在 tty_ioctl(4)
页面或 ioctl_list(4)
。
Sadly this ioctl is not documented in the tty_ioctl(4)
page nor in ioctl_list(4)
.
我在这个问题中了解了这个ioctl:
I have learned about this ioctl in this question:
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