Hi Everyone

I am doing some socket and serial programming.

I can follow along with things but there is something I just don't understand and it's fundamental.

So with serial programming on posix we include termios.h and there are various struct fields that can be set to different values.

Once these are all set up, the port itself is configured for use. I assume that other applications could actually access the port using the same parameters(assuming nothing is locked). I am assuming this is how the command stty works.

The thing I don't get is that if I am including some struct via an include file, am I not using a copy of this code. It seems like the changes are global though. Does the struct have function pointers in it that make the changes global.

I am not very far along with socket programming but is this the same situation, function pointers acting on the struct settings to make changes globally ?

Thanks for reading-Patrick

It would help if you posted a short (socket) code snippet

Hi Meson

My own code is snippets of trash I am too embarressed to post right now.

Here is a link to a wikipedia book:

http://en.wikibooks.org/wiki/Serial_Programming/termios

Most of this page deals with termios but this section clearly does:

Basic Configuration of a Serial Interface

Thanks

I was after snippets of socket programming that's confusing you.

Hi Meson

Sorry I am not being very helpful. I don't have anything to show.

I have been working through this book:

http://beej.us/guide/bgnet/

socket programming seems to be similar in that we are working with system structs but I have even less experience then serial.

Hi Everyone

I think I can answer my own question now. I just wanted to post back in case someone finds this later.

If I have a serial port configuration struct in memory and I have a bunch of functions that manipulate it, what good is that. Well it is if you have:

tcgetattr() to propagate the struct with what is already configured at the port beforehand and

tcsetattr() to apply all the settings from the in memory struct to the OS.

-Patrick