maximun number of message queues

how to check the maximun number of message queues in current linux enviornment? is there any command ?

Helo, If I've undertood you, try:

ipcs -l

Regards.

grial, thanks. that's what i want.

and, how to SET the "maximun number of message queues "?
any other command?

As far as I know, there is no command for that. Nevertheless, you can tune kernel parameters modifyig the files located at /proc/sys/kernel. In your case, there are three files regarding to IPC messages: msgmni (maximum number of message queue identifiers), msgmnb (maximum number of bytes in a single message queue) and msgmax (maximum size of a message). So, you should change msgmni (defaults to 16).
Notice you'll need to modify this every time you reboot so, for instance, add a script to the boot process so that it's configured every reboot. Perhaps theres is another way to do it, but I do not know it.

Regards.

grial, thank you. your reply helps a lot.