串行编程（硬件握手） [英] Serial programming (hardware handshake)

问题描述

我想编程使用C / C ++使用硬件握手在linux串行通信。实现了握手的信号是CTS（清除发送）和RTS（请求发送）。目前我设置的CTS信号的功能如下所示：

I'm trying to to program a serial communication using hardware handshake in linux using C/C++. The signals that implement the handshake are CTS (Clear to send) and RTS (Request to send). Currently my function for setting the CTS signal looks as follows:

int setCTS(int fd, int value) {
    int status;
    ioctl(fd, TIOCMGET, &status); // get the current port status
    if (value)
    	status |= TIOCM_CTS; // rise the CTS bit
    else
    	status &= ~TIOCM_CTS; // drop the CTS bit
    ioctl(fd, TIOCMSET, $status); // set the modified status
    return 0;
}

其中的 FD 的是端口的文件描述符的值的是信号要设置的值。至code这个功能我根据 HTTP：// WWW。 easysw.com/~mike/serial/serial.html#5_1 。

where fd is the file descriptor for the port and value is the value to be set for the signal. To code this function I based on http://www.easysw.com/~mike/serial/serial.html#5_1.

问题是，的gcc 的不承认任何示例中使用的常量。有什么建议？

The problem is that gcc does not recognize any of the constants used in the example. Any suggestions?

- 更新 -

我已经找到了答案。展望另一个例子， SYS / ioctl.h 声明常量。

I've found an answer. Looking to another example, sys/ioctl.h declares the constants.

推荐答案

这可能不适用于您的特定应用程序，但我想我会在这里发布的情况下，它可以帮助你或别人搜索。

This may not be applicable for your particular application, but I thought I'd post it here in case it helps you or someone else searching.

在与的termios 大多数系统中，可以设置在 CRTSCTS 标志 - ＆GT; c_cflags 传递给 tcsetattr ，并具备了的termios 结构成员内核或硬件做RTS / CTS流量控制你。

On most systems with termios, you can set the CRTSCTS flag in the ->c_cflags member of the termios structure that you pass to tcsetattr, and have the kernel or hardware do the RTS/CTS flow control for you.

（这不是POSIX，但因此它的它的两个BSD和衍生的SystemV系统几乎无处不在 - 包括Linux）。

(It's not POSIX, but it's on both BSD and SystemV derived systems so it's almost everywhere - including Linux).

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