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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <sys/types.h>
// Define the message structure
struct msg_buffer {
long msg_type;
char msg_text[100];
};
void print_queue_times(int msgid) {
struct msqid_ds info;
if (msgctl(msgid, IPC_STAT, &info) == -1) {
perror("msgctl IPC_STAT failed");
exit(1);
}
printf("Last send time (msg_stime): %s", ctime(&info.msg_stime));
printf("Last recv time (msg_rtime): %s", ctime(&info.msg_rtime));
printf("Last change time (msg_ctime): %s", ctime(&info.msg_ctime));
}
int main() {
key_t key;
int msgid;
struct msqid_ds buf;
// Generate a unique key
key = ftok("progfile", 65);
// Create a message queue and return its id
msgid = msgget(key, 0666 | IPC_CREAT);
if (msgid == -1) {
perror("msgget failed");
exit(EXIT_FAILURE);
}
// Prepare message to send
struct msg_buffer message;
message.msg_type = 1;
strcpy(message.msg_text, "Hello from message queue!");
// Send the message
if (msgsnd(msgid, &message, sizeof(message.msg_text), 0) < 0) {
perror("msgsnd failed");
exit(EXIT_FAILURE);
}
printf("Message sent: %s\n", message.msg_text);
print_queue_times(msgid); // Show msg_stime after sending
// Get information about the message queue
if (msgctl(msgid, IPC_STAT, &buf) == -1) {
perror("msgctl - IPC_STAT failed");
exit(EXIT_FAILURE);
}
// Print some info from the msqid_ds structure
printf("Message queue ID: %d\n", msgid);
// Receive the message
struct msg_buffer received;
if (msgrcv(msgid, &received, sizeof(received.msg_text), 1, 0) < 0) {
perror("msgrcv failed");
exit(EXIT_FAILURE);
}
printf("Message received: %s\n", received.msg_text);
print_queue_times(msgid); // Show msg_stime after receiving
// Remove the message queue
if (msgctl(msgid, IPC_RMID, NULL) == -1) {
perror("msgctl - IPC_RMID failed");
exit(EXIT_FAILURE);
}
printf("Message queue removed successfully.\n");
return 0;
}
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