Programming

    if(pipe(fd)==-1){
        perror("Pipe Failed");
        myExit(EXIT_FAILURE);
    }

    close(fd[1]);    
    sprintf(fdString,"%d",fd[1]);

        .......

    if((int)(pid=fork())>0)
        
        waiting(status);    
    
    else if(pid==0){    
        
        close(fd[0]);    

        execl("./B","B",fdString,(char*)0);
        perror("Exec failed");
        myExit(EXIT_FAILURE);

    }

    int fd=atoi(argv[1]);
        
        //Receive string from C 

           len=strlen(string)+1;

    if(write(fd,&len,sizeof(int))==-1){
        perror("Error on writing length");
        exit(EXIT_FAILURE);    
    }

    if(write(fd,&string,len)==-1){
        perror("Error on writing string");
        exit(EXIT_FAILURE);        
    }

    signal(SIGUSR1, signalHandler);
        ........
          static void signalHandler(int signo){
        switch(signo){
        case SIGUSR1:
            listen();
            break;
        default: break;

        }
    }
        ........
    static void listen(){
    
        int len;
    
        if(read(fd[0],&len,sizeof(int))<sizeof(int)){
            perror("Error reading len");
            myExit(EXIT_FAILURE);    
        }
    
        char string[len];
    
        if(read(fd[0],string,len)<len){
            perror("Error reading string");
            myExit(EXIT_FAILURE);    
        }
        printf("String: %s with length %d\n", string, len);
    }