c - What key to put on the receiver side of Linux message queues? -

i have created message queue , sender part creates , sends message message queue.

i have used ipc_private key in msgget() on sender side.

now question is, key use in msgget() on receiver side ?

using ipc_private on receiver side key in msgget() not receive message , fails.

i should mention msgsnd() in sender part indicates error (returns -1), when printing perror(), output success , message sent message queue , can seen using ipcs -q command @ terminal. don't know why happens.

 if(msgsnd(msqid,&msgp,88,ipc_nowait) == 0)           {                   perror("\nsend : msgsnd fail");                   msgctl(msqid,ipc_rmid,buf);                   return 1;           } 

output : send : msgsnd fail: success

you going have use common key value between 2 independent processes ... using ipc_private means not planning on sharing queue between 2 processes unless secondary process has been forked first process. because of forking operation, child inherent queue identifier parent process, using ipc_prvate in scenario okay. because using ipc_private creates unique key-value every call used in, scenarios have 2 independent processes, such server/client relationship, need create common key ... can either "magic number" share between processes not in-use queue, shared memory segment, etc., or can create key off common file in filesystem using ftok().