signalqueue

#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#define MSG_SZ_MAX 255

struct message{
    long mtype;
    pid_t pid;
    char mtext[MSG_SZ_MAX];
};

int descr;
struct message sendMsg, recieveMsg;

static void sigHandle(int signum);


void main(){
    descr = msgget(10, IPC_CREAT|0666);
    printf("descriptor : %d\n", descr);
    printf("PID : %d\n", getpid());

    if(signal(SIGINT, sigHandle) == SIG_ERR){
        perror("Can't handle a signal SIGINT.");
        exit(1);
    }
    if(signal(SIGUSR1, sigHandle) == SIG_ERR){
        perror("Can't handle a signal SIGUSR1.");
        exit(1);
    }
    if(signal(SIGTERM, sigHandle) == SIG_ERR){
        perror("Can't handle a signal SIGTERM.");
        exit(1);
    }

    printf("Receiver's PID : ");
    pid_t pidRes;
    scanf("%d", &pidRes);

    sendMsg.mtype = pidRes;
    sendMsg.pid = getpid();
    recieveMsg.mtype = getpid();


    if(descr==-1){
        perror("msgget");
    }

    while(1){

        strcpy(sendMsg.mtext, "[");
        //strcat(sendMsg.mtext, (char*)getpid);
        char senderpid[10];
        snprintf(senderpid, 10, "%ld", (long)getpid());
        strcat(sendMsg.mtext, senderpid);
        strcat(sendMsg.mtext, "] : ");

        /*
        *sendMsg.mtext += sprintf(sendMsg.mtext, "%s", "[");
        *sendMsg.mtext += sprintf(sendMsg.mtext, "%ld", (long)getpid());
        *sendMsg.mtext += sprintf(sendMsg.mtext, "%s", "] : ");*/

        char buf[MSG_SZ_MAX];
        /**
        *INPUT
        */
        scanf("%s", buf);
        strcat(sendMsg.mtext, buf);
        //fgets(buf, MSG_SZ_MAX, stdin);
        //*sendMsg.mtext += sprintf(sendMsg.mtext, "%s", buf);

        if(msgsnd(descr, &sendMsg, sizeof(struct message), 0) == -1){
            perror("msgsnd");
            exit(2);
        }

        while(1){
            if(msgrcv(descr, &recieveMsg, sizeof(struct message), getpid(), IPC_NOWAIT) != -1){
                printf("%s\n", recieveMsg.mtext);
            } else break;
        }
    }
}

static void sigHandle(int signum){
    if(signum == SIGUSR1){
        printf("\nOther process has been terminated.\n");
        exit(0);
    }
    if(signum == SIGINT){
        kill(recieveMsg.pid, SIGUSR1);
        msgctl(descr, IPC_RMID, 0);
        exit(0);
    }
    if(signum == SIGTERM){
        printf("\nSIGTERM has been received, terminated.\n");
        kill(recieveMsg.pid, SIGUSR1);
        msgctl(descr, IPC_RMID, 0);
        exit(0);
    }
}