Add stand-alone example program w/ Makefile and README

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

Makefile.am

@@ -16,7 +16,7 @@
 # with this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
-SUBDIRS        = man src test
+SUBDIRS        = example man src test
 doc_DATA       = README.md ChangeLog.md syslog.conf
 EXTRA_DIST     = README.md ChangeLog.md syslog.conf
 

configure.ac

@@ -26,6 +26,7 @@ AC_CONFIG_MACRO_DIRS([m4])
 AC_CONFIG_SRCDIR([src/syslogd.c])
 AC_CONFIG_HEADER([config.h])
 AC_CONFIG_FILES([Makefile
+		 example/Makefile
 		 man/Makefile
 		 src/Makefile
 		 src/libsyslog.pc

example/Makefile.am

@@ -0,0 +1,4 @@
+EXTRA_DIST      = README.md example.c example.mk
+
+pkgexampledir   = $(docdir)/example
+pkgexample_DATA = $(EXTRA_DIST)

example/README.md

@@ -0,0 +1,55 @@
+Stand-alone Example syslogp() Application
+=========================================
+
+This is a *very* simple stand-alone example application.  The purpose is
+to show how to use the sysklogd 2.x API, e.g. `syslogp()`, to use "new"
+RFC5424 features like MsgID.
+
+Included in this directory are two files:
+
+ - `example.c`: actual C code example
+ - `example.mk`: plain Makefile for building `example`
+
+Provided the two files are in the same (writable) directory, you can
+build the application like this:
+
+    make -f example.mk
+
+
+GNU Autotools
+-------------
+
+If you want to use GNU autoconf & automake instead.  The following is
+recommended in `configure.ac` and `Makefile.am` to build your
+application.
+
+```sh
+# configure.ac (snippet)
+
+# Check for pkg-config tool, required for next step
+PKG_PROG_PKG_CONFIG
+
+# Check for required libraries
+PKG_CHECK_MODULES([syslog], [libsyslog >= 2.0])
+```
+
+and
+
+```Makefile
+# Makefile.am (snippet)
+
+bin_PROGRAMS    = example
+
+example_SOURCES = example.c
+example_CFLAGS  = $(syslog_CFLAGS)
+example_LDADD   = $(syslog_LIBS)
+```
+
+**NOTE:** Most free/open source software that uses `configure` default
+  to install to `/usr/local`.  However, some Linux distributions do no
+  longer search that path for installed software, e.g. Fedora and Alpine
+  Linux.  To help your configure script find its dependencies you have
+  to give the `pkg-config` a prefix path:
+
+    PKG_CONFIG_LIBDIR=/usr/local/lib/pkgconfig ./configure
+

example/example.c

@@ -0,0 +1,44 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 1983, 1988, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/* Example of how to use NetBSD syslogp() API with libsyslog from sysklogd */
+
+#include <stdio.h>
+#include <syslog/syslog.h>
+
+int main(void)
+{
+        openlog("example", LOG_PID, LOG_USER);
+        syslogp(LOG_NOTICE, "MSGID", NULL, "Kilroy was here.");
+	closelog();
+
+	return 0;
+}

example/example.mk

@@ -0,0 +1,10 @@
+# Simple Makefile for syslogp() example application
+#
+EXEC     := example
+OBJS     := example.o
+CFLAGS   := `pkg-config --cflags libsyslog`
+LDLIBS   := `pkg-config --libs --static libsyslog`
+
+all: $(EXEC)
+
+$(EXEC): $(OBJS)