Update MentOs code to the latest development version.

programs/tests/t_stopcont.c

@@ -0,0 +1,60 @@
+///                MentOS, The Mentoring Operating system project
+/// @file t_stopcont.c
+/// @brief
+/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// See LICENSE.md for details.
+
+#include <sys/unistd.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+#include "stdlib.h"
+#include <sys/wait.h>
+
+int child_pid;
+
+void wait_for_child(int signr)
+{
+    printf("Signal received: %s\n", strsignal(signr));
+    sleep(10);
+
+    printf("Sending continue sig to child\n");
+    if (kill(child_pid, SIGCONT) == -1)
+        printf("Error sending signal\n");
+}
+
+int main(int argc, char *argv[])
+{
+    sigaction_t action;
+    memset(&action, 0, sizeof(action));
+    action.sa_handler = wait_for_child;
+    if (sigaction(SIGCHLD, &action, NULL) == -1) {
+        printf("Failed to set signal handler. %d\n", SIGCHLD);
+        return 1;
+    }
+
+    child_pid = fork();
+    if (child_pid != 0) {
+        printf("Child PID: %d\n", child_pid);
+
+        sleep(2);
+        printf("Sending stop sig to child\n");
+
+#if 1
+        if (kill(child_pid, SIGSTOP) == -1)
+            printf("Errore invio stop\n");
+#endif
+
+        wait(NULL);
+    } else {
+        int c = 0;
+        for (;;) {
+            printf("c: %d\n", c++);
+            sleep(3);
+        }
+    }
+
+    return 0;
+}