Fix SIGPIPE causing unexpected exit of example applications

examples/client.c:
examples/coap-rd.c:
examples/coap-server.c:
examples/etsi_iot_01.c:
examples/tiny.c:

Make the applications ignore SIGPIPE.

examples/coap-rd.c:

Support clean exit for SIGTERM / SIGQUIT for valgrind testing.

examples/client.c

@@ -1569,6 +1569,9 @@ main(int argc, char **argv) {
   sa.sa_flags = 0;
   sigaction (SIGINT, &sa, NULL);
   sigaction (SIGTERM, &sa, NULL);
+  /* So we do not exit on a SIGPIPE */
+  sa.sa_handler = SIG_IGN;
+  sigaction (SIGPIPE, &sa, NULL);
 #endif
 
   while (!quit && !(ready && !doing_getting_block && coap_can_exit(ctx)) ) {

examples/coap-rd.c

@@ -85,9 +85,14 @@ rd_delete(rd_t *rd) {
   }
 }
 
-/* temporary storage for dynamic resource representations */
 static int quit = 0;
 
+/* SIGINT handler: set quit to 1 for graceful termination */
+static void
+handle_sigint(int signum UNUSED_PARAM) {
+  quit = 1;
+}
+
 static void
 hnd_get_resource(coap_context_t  *ctx UNUSED_PARAM,
                  struct coap_resource_t *resource,
@@ -620,6 +625,9 @@ main(int argc, char **argv) {
   char *group = NULL;
   int opt;
   coap_log_t log_level = LOG_WARNING;
+#ifndef _WIN32
+  struct sigaction sa;
+#endif
 
   while ((opt = getopt(argc, argv, "A:g:p:v:")) != -1) {
     switch (opt) {
@@ -656,6 +664,20 @@ main(int argc, char **argv) {
 
   init_resources(ctx);
 
+#ifdef _WIN32
+  signal(SIGINT, handle_sigint);
+#else
+  memset (&sa, 0, sizeof(sa));
+  sigemptyset(&sa.sa_mask);
+  sa.sa_handler = handle_sigint;
+  sa.sa_flags = 0;
+  sigaction (SIGINT, &sa, NULL);
+  sigaction (SIGTERM, &sa, NULL);
+  /* So we do not exit on a SIGPIPE */
+  sa.sa_handler = SIG_IGN;
+  sigaction (SIGPIPE, &sa, NULL);
+#endif
+
   while ( !quit ) {
     result = coap_run_once( ctx, COAP_RESOURCE_CHECK_TIME * 1000 );
     if ( result >= 0 ) {

examples/coap-server.c

@@ -983,6 +983,9 @@ main(int argc, char **argv) {
   sa.sa_flags = 0;
   sigaction (SIGINT, &sa, NULL);
   sigaction (SIGTERM, &sa, NULL);
+  /* So we do not exit on a SIGPIPE */
+  sa.sa_handler = SIG_IGN;
+  sigaction (SIGPIPE, &sa, NULL);
 #endif
 
   wait_ms = COAP_RESOURCE_CHECK_TIME * 1000;

examples/etsi_iot_01.c

@@ -662,6 +662,9 @@ main(int argc, char **argv) {
   sa.sa_flags = 0;
   sigaction (SIGINT, &sa, NULL);
   sigaction (SIGTERM, &sa, NULL);
+  /* So we do not exit on a SIGPIPE */
+  sa.sa_handler = SIG_IGN;
+  sigaction (SIGPIPE, &sa, NULL);
 
   while ( !quit ) {
     result = coap_run_once( ctx, COAP_RESOURCE_CHECK_TIME * 1000 );

examples/tiny.c

@@ -148,6 +148,9 @@ main(int argc, char **argv) {
   sa.sa_flags = 0;
   sigaction (SIGINT, &sa, NULL);
   sigaction (SIGTERM, &sa, NULL);
+  /* So we do not exit on a SIGPIPE */
+  sa.sa_handler = SIG_IGN;
+  sigaction (SIGPIPE, &sa, NULL);
 
   while ( !quit ) {