fix: corner cases when printing large content through term interface

[lunaix-os.git] / lunaix-os / usr / signal_demo.c

diff --git a/lunaix-os/usr/signal_demo.c b/lunaix-os/usr/signal_demo.c
new file mode 100644 (file)
index 0000000..352d0de
--- /dev/null
+++ b/lunaix-os/usr/signal_demo.c
@@ -0,0 +1,77 @@
+#include <lunaix/lunaix.h>
+#include <signal.h>
+#include <stdio.h>
+#include <unistd.h>
+
+void
+sigchild_handler(int signum)
+{
+    printf("SIGCHLD received\n");
+}
+
+void
+sigsegv_handler(int signum)
+{
+    pid_t pid = getpid();
+    printf("SIGSEGV received on process %d\n", pid);
+    _exit(signum);
+}
+
+void
+sigalrm_handler(int signum)
+{
+    pid_t pid = getpid();
+    printf("I, pid %d, have received an alarm!\n", pid);
+}
+
+int
+main()
+{
+    signal(SIGCHLD, sigchild_handler);
+    signal(SIGSEGV, sigsegv_handler);
+    signal(SIGALRM, sigalrm_handler);
+
+    int status;
+    pid_t p = 0;
+
+    alarm(5);
+
+    printf("Child sleep 3s, parent pause.\n");
+    if (!fork()) {
+        sleep(3);
+        _exit(0);
+    }
+
+    pause();
+
+    printf("Parent resumed on SIGCHILD\n");
+
+    for (int i = 0; i < 5; i++) {
+        pid_t pid = 0;
+        if (!(pid = fork())) {
+            signal(SIGSEGV, sigsegv_handler);
+            sleep(i);
+            if (i == 3) {
+                i = *(int*)0xdeadc0de; // seg fault!
+            }
+            printf("%d\n", i);
+            _exit(0);
+        }
+        printf("Forked %d\n", pid);
+    }
+
+    while ((p = wait(&status)) >= 0) {
+        short code = WEXITSTATUS(status);
+        if (WIFSIGNALED(status)) {
+            printf("Process %d terminated by signal, exit_code: %d\n", p, code);
+        } else if (WIFEXITED(status)) {
+            printf("Process %d exited with code %d\n", p, code);
+        } else {
+            printf("Process %d aborted with code %d\n", p, code);
+        }
+    }
+
+    printf("done\n");
+
+    return 0;
+}
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