added some c code

rewrite/client.c

@@ -0,0 +1,21 @@
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <mqueue.h>
+#include <signal.h>
+
+void cont_handler(int sig) {
+    if (sig != SIGCONT) return;
+}
+
+int main() {
+    mqd_t q = mq_open("/res_request", O_WRONLY);
+
+    if (q == (mqd_t) -1) {
+        fprintf(stderr, "Error making queue: %s\n", strerror(errno));
+    }
+
+    const char *str = "Hello, world! This is my message.";
+    mq_send(q, str, strlen(str), 0);
+}

rewrite/manager.c

@@ -0,0 +1,46 @@
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <mqueue.h>
+
+#define BUFSZ 256
+
+void cleanup(int sig) {
+    mq_unlink("/res_request");
+
+    exit(sig < 0 ? EXIT_FAILURE : EXIT_SUCCESS);
+}
+
+int main() {
+    struct mq_attr attr;
+    mqd_t q;
+
+    char buff[BUFSZ + 1];
+    ssize_t nread;
+
+    attr.mq_maxmsg = 10;
+    attr.mq_msgsize = BUFSZ;
+
+    mq_unlink("/res_request");
+    q = mq_open("/res_request", O_RDONLY | O_CREAT | O_EXCL, 0644, &attr);
+
+    if (q == (mqd_t) -1) {
+        fprintf(stderr, "Error making queue (%d): %s\n", errno, strerror(errno));
+        cleanup(-1);
+    }
+
+    signal(SIGINT, cleanup);
+    printf("Waiting.\n");
+
+    while ((nread = mq_receive(q, buff, BUFSZ, NULL)) != -1) {
+        printf("Got %zd bytes: %s\n", nread, buff);
+        sleep(3);
+    }
+
+    fprintf(stderr, "Error receiving: %s\n", strerror(errno));
+    exit(EXIT_FAILURE);
+}