C program to create a message queue with read and write permissions to write 3 messages to it with different priority numbers

msgget():The msgget function can be used to create the message queue. msgrcv():The msgrcv function can be used to receive the messages. msgsnd():The msgsnd function can be used to send the messages to another process 
				
					#include <stdio.h> 
#include <sys/ipc.h> 
#include <fcntl.h>
#define MAX 255 
struct mesg 
{
long type; 
char mtext[MAX]; 
}
*mesg;
char buff[MAX]; 
main() 
{
int mid,fd,n,count=0;;
if((mid=msgget(1006,IPC_CREAT | 0666))<0) 
{
printf(“\n Can‟t create Message Q”); 
exit(1);
}
printf(“\n Queue id:%d”, mid);
mesg=(struct mesg *)malloc(sizeof(struct mesg)); 
mesg ->type=6;
fd=open(“fact”,O_RDONLY); 
while(read(fd,buff,25)>0) 
{ 
strcpy(mesg ->mtext,buff); 
if(msgsnd(mid,mesg,strlen(mesg ->mtext),0)== -1) 
printf(“\n Message Write Error”);
}
if((mid=msgget(1006,0))<0) 
{
printf(“\n Can‟t create Message Q”);
exit(1); 
}
while((n=msgrcv(mid,&mesg,MAX,6,IPC_NOWAIT))>0) 
write(1,mesg.mtext,n); 
count ; 
if((n= = -1)&(count= =0)) 
printf(“\n No Message Queue on Queue:%d”,mid);
}

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