When using a serial port via POSIX, it's recommended to save the original attributes using tcgetattr() before changing them with tcsetattr(), and then restore them before closing the port. What about when a program is terminated by pressing control-C or when the program receives SIGINT? I haven't seen this covered in any of the serial tutorials.
Apparently an atexit() function wouldn't be sufficient, because it's not called by the default SIGINT handler. So it seems installation of a signal handler would be necessary that restores the attributes to any serial ports still open. Is it even safe to call tcsetattr() from a signal handler?
One might simply dismiss this issue as insignificant, but it's common to terminate a program with control-C, especially one that can take tens of seconds to complete operations. If it's OK not to preserve serial port settings in this case, then there seems little reason to preserve them at all. If anything, it might be better not to bother, rather than do it inconsistently.
I found some examples of source code doing the above, but nothing well-documented. I guess I'm interested in some discussion of whether this is a good idea. Thanks.