int main(int argc, char *argv[])
{
struct mymsgbuf qbuf;
char key_id[16];
key_t key;
int msgid, type;
unsigned short opperm;
char cmd[MAX_SIZE] = { 0 };
printf ( "Message queues present in the system\n" );
system("ipcs -q");
printf( "\nEnter the desired key in hex (form: 0x0807633d, 0x0 for IPC_PRIVATE)\n or queue's id in decimal: ");
scanf( "%15s", key_id);
if ( sscanf( key_id, "0x%x", &key ) == 0 ) { // key_id represents an ID
sscanf( key_id, "%d", &msgid );
printf( "\nmsgid = %d", msgid );
} else { // key_id is a key, otherwise
msgid = msgget_wrapper( key );
if ( msgid == -1 )
syserr("msgget");
}
printf( "\nmsgid = %d\n", msgid );
while (1) {
fprintf(stderr, "\nChoose an action:\n");
fprintf(stderr, " (s)end <type> <messagetext>\n");
fprintf(stderr, " (r)ecv <type>\n");
fprintf(stderr, " (d)elete\n");
fprintf(stderr, " (m)ode <octal mode>\n");
fprintf(stderr, " (q)uit the application\n");
scanf("%s", cmd);
switch(tolower(cmd[0])) {
case 's':
scanf("%d", &type);
fgets(cmd, MAX_SIZE-1, stdin);
send_message(msgid, &qbuf, type, cmd);
break;
case 'r':
scanf("%d", &type);
read_message(msgid, &qbuf, type);
break;
case 'd':
remove_queue(msgid);
break;
case 'm':
scanf("%ho", &opperm);
change_queue_mode(msgid, opperm);
break;
case 'q':
return 0;
}
}
return 0 ;
}
int main(int argc, char *argv[])
{
key_t key;
int msgqueue_id;
struct mymsgbuf qbuf;
if(argc == 1)
usage();
/* Create unique key via call to ftok() */
key = ftok(".", 'm');
/* Open the queue - create if necessary */
if((msgqueue_id = msgget(key, IPC_CREAT|0660)) == -1) {
perror("msgget");
exit(1);
}
switch(tolower(argv[1][0]))
{
case 's':
send_message(msgqueue_id, (struct mymsgbuf *)&qbuf,
atol(argv[2]), argv[3]);
break;
case 'r':
read_message(msgqueue_id, &qbuf, atol(argv[2]));
break;
case 'd':
remove_queue(msgqueue_id);
break;
case 'm':
change_queue_mode(msgqueue_id, argv[2]);
break;
default:
usage();
}
return(0);
}
int main(int argc, char *argv[])
{
key_t key;
int msgqueue_id; //消息队列标识符
struct mymsgbuf qbuf;
if (argc == 1)
usage();
/*create unique key via call to ftok()*/
key = ftok(".", 'm');
/*open the queue - create if necessary*/
if ((msgqueue_id = msgget(key, IPC_CREAT | 0660)) == -1) {
perror("msgget");
exit(1);
}
/*关于argv[1][0]的解释来自：stackoverflow.com/questions/11757951/what-is-the-meaning-of-argv10(foreign Web)
* as others have pointed out, argv[1] is the second string in the string array argv,
* and strings are character arrays so argv[1][0] is the first character in the second
* string.
* that is(也就是说)：it means the first character of the second string of argv.
* */
switch (tolower(argv[1][0])) {
case 's': send_message(msgqueue_id, (struct mymsgbuf *)&qbuf, atol(argv[2]), argv[3]);
break;
case 'r': read_message(msgqueue_id, &qbuf, atol(argv[2])); //atol:将字符串转换成长整型数
break;
case 'd': remove_queue(msgqueue_id);
break;
case 'm': change_queue_mode(msgqueue_id, argv[2]);
break;
default: usage();
}
return 0;
}
