Multiline message sending in C doesn't work

Question

I use message queue in C and sending information about all files (in current folder) from the client to server (MSGMAX defined as 4096). Client code:

    int mq_id;
    struct { long type; char text[MSGMAX]; } mymsg;
    mq_id = msgget(12, IPC_CREAT | 0666);
FILE* p;
char str[MSGMAX];
p = popen("ls -l", "r");
while (fgets(str, MSGMAX, p)){ strcpy (mymsg.text, str); }
pclose(p);
mymsg.type = 1;
msgsnd(mq_id, &mymsg, sizeof(mymsg), IPC_NOWAIT);
}

In this part mymsg.text returns correct multline string (result of ls -l ). But when I tried to print this string in server part, it retured only last line of whole string:

    int mq_id;
    struct { long type; char text[MSGMAX]; } mymsg;
    mq_id = msgget(12, 0);
    if (msgrcv(mq_id, &mymsg, sizeof(mymsg), 0, 0) < 0)
    perror("\nMsg error!");
    else
    printf("%s", mymsg.text);

How could I send mymsg.text completely, with all lines?

Answer 1

With while (fgets(str, MSGMAX, p)){ strcpy (mymsg.text, str); } while (fgets(str, MSGMAX, p)){ strcpy (mymsg.text, str); } , you will override the contents of mymsg.txt with every new line read by fgets . I'd suggest to write something like...

strcpy(mymsg.text,"");
while (fgets(str, MSGMAX, p)){ strcat (mymsg.text, str); }

or you send the buffer to the server within the loop, ie sending every line read separately.