Message receive program only printing every other message - c

Question

I am have implemented the two programs from section 7.6 of http://beej.us/guide/bgipc/output/html/multipage/mq.html.
I have extended it so that there are two receiving programs and which one it goes to is determined by the message type.
The problem arises in the receiving program, B and C. They are supposed to print out the messages entered into program A everytime, however they only print the messages every other time.
This is where the message is sent, it reads the first 6 chars and if it is URGENT it sets the the message type.
buf.mtype = 2;
while(fgets(buf.mtext, sizeof buf.mtext, stdin) != NULL) {
int len = strlen(buf.mtext);
strncpy(typeTest, buf.mtext, 6);
if(strncmp(typeTest, "URGENT", 6) == 0){
buf.mtype = 1;
}
printf("This is the message %s \n", buf.mtext);
/* ditch newline at end, if it exists */
if (buf.mtext[len-1] == '\n') buf.mtext[len-1] = '\0';
if (msgsnd(msqid, &buf, len+1, 0) == -1) /* +1 for '\0' */
perror("msgsnd");
}
This is where the message is received, then the if statement checks the type to then print out.
for(;;) { /* Spock never quits! */
if (msgrcv(msqid, &buf, sizeof buf.mtext, 0, 0) == -1) {
perror("msgrcv");
exit(1);
}
if(buf.mtype == 2){
printf("spock: \"%s\"\n", buf.mtext);
}
}
Can anyone shed some light on why it only prints out every other message?
Thanks.

Answer 1

In your program A you must set buf.mtype to 2 if the input is not "URGENT..." You must do that in the loop, every time.
while(fgets(buf.mtext, sizeof buf.mtext, stdin) != NULL) {
int len = strlen(buf.mtext);
strncpy(typeTest, buf.mtext, 6);
if(strncmp(typeTest, "URGENT", 6) == 0){
buf.mtype = 1;
}
else buf.mtype= 2; // always set the default
printf("This is the message %s \n", buf.mtext);
/* ditch newline at end, if it exists */
if (buf.mtext[len-1] == '\n') buf.mtext[len-1] = '\0';
if (msgsnd(msqid, &buf, len+1, 0) == -1) /* +1 for '\0' */
perror("msgsnd");
}
In your programs B and C you must set msgtyp to 1 or 2 for each program to get the right message from the queue, for example:
int main(argc, argv)
{
int msgtype;
if (*argv[1]=='A')
msgtype= 1;
else if (*argv[1]=='B')
msgtype= 2;
else
msgtype= 0;
...
for(;;) { /* Spock never quits! */
if (msgrcv(msqid, &buf, sizeof buf.mtext, msgtype, 0) == -1) {
perror("msgrcv");
exit(1);
}
if(buf.mtype == msgtype){
printf("spock: \"%s\"\n", buf.mtext);
}
}
return 0;
}