Introduce posix tests package

test/posix/signal_test.c

@@ -0,0 +1,55 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2023 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include <signal.h>
+#include <stdlib.h>
+
+volatile sig_atomic_t signal_received = 0;
+
+void signal_handler(int signum) {
+  // Set the flag to indicate the signal was received
+  signal_received = 1;
+}
+
+int main() {
+  // Install the signal handler
+  struct sigaction sa;
+  sa.sa_handler = signal_handler;
+  sigemptyset(&sa.sa_mask);
+  sa.sa_flags = 0;
+
+  if (sigaction(SIGUSR1, &sa, NULL) == -1) {
+    // Failed to install signal handler
+    exit(1);
+  }
+
+  // Raise the signal
+  if (raise(SIGUSR1) != 0) {
+    // Failed to raise signal
+    exit(2);
+  }
+
+  // Check if the signal was received
+  if (signal_received == 1) {
+    // Signal was successfully caught
+    exit(0);
+  } else {
+    // Signal was not caught
+    exit(3);
+  }
+}