Message queue in C

This is an excellent tutorial for message queues in linux good for starters.
http://beej.us/guide/bgipc/output/html/multipage/mq.html
But it is system V implementation and does not support signal generation.

Hence we go for POSIX Message Queues.
Note:- While compiling put the linker flag -'lrt' .
gcc -o msg_recv msg_recv.c -lrt