* compile dummy for non-linux

* link to systemd instead of systemd-journal on newer systems

.gitignore

@@ -26,3 +26,4 @@ Makefile
 *.iws
 .rakeTasks
 .idea
+extconf.h

ext/journald_native/extconf.rb

@@ -9,12 +9,27 @@ LIB_DIRS = [LIBDIR]
 
 dir_config('systemd', HEADER_DIRS, LIB_DIRS)
 
+def have_funcs
+  have_funcs = true
+
+  # check functions. redefine const list in sd_journal.h if changed
+  %w(sd_journal_print sd_journal_sendv sd_journal_perror).each do |func|
+    have_funcs &&= have_func(func)
+  end
+
+  have_funcs
+end
+
 # check headers
-abort 'systemd/sd-journal.h is missing. please install systemd-journal' unless find_header('systemd/sd-journal.h')
+have_header('systemd/sd-journal.h')
+
+# first try to find funcs in systemd
+have_library('systemd')
 
-# check functions
-%w(sd_journal_print sd_journal_sendv sd_journal_perror).each do |func|
-   abort "#{func}() is missing. systemd-journal is not usable" unless find_library('systemd-journal', func)
+unless have_funcs
+  have_library('systemd-journal') # try to fall back to systemd-journal if older systemd
 end
 
+create_header
 create_makefile('journald_native')
+

ext/journald_native/journald_native.c

@@ -2,7 +2,7 @@
 #define SD_JOURNAL_SUPPRESS_LOCATION
 
 #include <ruby.h>
-#include <systemd/sd-journal.h>
+#include "sd_journal.h"
 
 void Init_journald_native();
 
@@ -73,7 +73,7 @@ static VALUE jdl_native_print(VALUE v_self, VALUE v_priority, VALUE v_message)
 static VALUE jdl_native_send(int argc, VALUE* argv, VALUE self)
 {
     struct iovec *msgs;
-    size_t i;
+    int i;
     int result;
 
     /* first check everything is a string / convertable to string */

ext/journald_native/sd_journal.h

@@ -0,0 +1,63 @@
+#ifndef JOURNALD_NATIVE_SD_JOURNAL_H
+    #define JOURNALD_NATIVE_SD_JOURNAL_H
+
+    #ifdef __linux__
+
+        /* do the real stuff */
+
+        #include "extconf.h"
+
+        /* check for extconf results */
+
+        #ifndef HAVE_SYSTEMD_SD_JOURNAL_H
+            #error Cannot include <systemd/sd-journal.h>. Please use linux version with systemd-journal installed
+        #endif
+
+        #ifndef HAVE_SD_JOURNAL_PRINT
+            #error Required function sd_journal_print is missing
+        #endif
+
+        #ifndef HAVE_SD_JOURNAL_SENDV
+            #error Required function sd_journal_sendv is missing
+        #endif
+
+        #ifndef HAVE_SD_JOURNAL_PERROR
+            #error Required function sd_journal_perror is missing
+        #endif
+
+        /* include systemd-journal headers */
+
+        #include <systemd/sd-journal.h>
+
+    #else
+
+        #warning Compiling dummy version of the gem for non-Linux OS
+
+        #include <stdlib.h>
+
+        /* use dummy */
+        #define JOURNALD_NATIVE_SYSTEMD_JOURNAL_DUMMY
+
+        /* syslog constants */
+        #define LOG_EMERG   0
+        #define LOG_ALERT   1
+        #define LOG_CRIT    2
+        #define LOG_ERR     3
+        #define LOG_WARNING 4
+        #define LOG_NOTICE  5
+        #define LOG_INFO    6
+        #define LOG_DEBUG   7
+
+        /* iovec */
+        struct iovec {
+            void  *iov_base;    /* Starting address */
+            size_t iov_len;     /* Number of bytes to transfer */
+        };
+
+        int sd_journal_print(int priority, const char *format, ...);
+        int sd_journal_sendv(const struct iovec *iov, int n);
+        int sd_journal_perror(const char *message);
+
+    #endif
+
+#endif

ext/journald_native/sd_journal_dummy.c

@@ -0,0 +1,9 @@
+#include "sd_journal.h"
+
+#ifdef JOURNALD_NATIVE_SYSTEMD_JOURNAL_DUMMY
+
+int sd_journal_print(int priority, const char *format, ...) { return 0; }
+int sd_journal_sendv(const struct iovec *iov, int n)        { return 0; }
+int sd_journal_perror(const char *message)                  { return 0; }
+
+#endif

lib/journald/native/version.rb

@@ -1,5 +1,5 @@
 module Journald
   module Native
-    VERSION = '1.0.2'
+    VERSION = '1.0.3'
   end
 end