Message queues with custom buffers

estratos · 12-16-2006, 02:56 PM

Hi all.

I'm want to use a message queue to make communicate an application with a cgi. Following the msgsnd/msgrcv man page, queue buffers shall follow this type:

Code:

struct msgbuf {
   long mtype;
   char mtext[1];
};

Have anyone tryed with a custom structure? I'm thinking in something like this:

Code:

struct mymsgbuf {
   long mtype;
   int index;
   char mtext[32];
};

Can I use my own send/receive message structure with msgsnd and msgrcv? I feel that the original structure is a bit limited for my needs.

Thanks for your help,

Daniel.

Mara · 12-16-2006, 03:12 PM

You can use any (resonable) structure size. When keeping mtype and mtext only you can always cast mtext to some more interesting type, like structure etc, so it does not have to be a simple string (as long as you control what you write and test it, as it may lead to many nasty bugs).

estratos · 12-17-2006, 03:13 AM

Thanks Mara. I'll cast mtext to my own structure type.