Merge pull request #177 from mdaus/better_path_for_binary_release

Better path for binary release

README.md

@@ -212,9 +212,16 @@ of fixing it later, which will make me eternally grateful.
 
 NITF Library Users: General Issues
 ----------------------------------
-If you want to use the default TRE plugins that come with the library,
-NITRO already knows where they are installed, and you don't have to
-do anything.
-
-If you want to override this behavior, you can set the
-`NITF_PLUGIN_PATH` environment variable to your preferred location.
+NITRO handles TREs by loading dynamic libraries at runtime. Therefore, you need
+to make sure NITRO can find them.
+
+* If you are building from source, the location will be compiled in, and
+  you don't have to do anything extra.
+
+* If you are working from a binary release, you will have to tell
+  NITRO where the plugins are by setting the `NITF_PLUGIN_PATH`
+  enviornment variable.
+  This should look something like `<install>/share/nitf/plugins`.
+
+* If you wish to use a custom TRE location, you can also specify that
+  with `NITF_PLUGIN_PATH`.

modules/c/nitf/source/PluginRegistry.c

@@ -262,12 +262,24 @@ NITFPRIV(nitf_PluginRegistry*) implicitConstruct(nitf_Error* error)
     if (!pluginEnvVar)
     {
         /*  Take the default path  */
-        strcpy(reg->path, NITF_DEFAULT_PLUGIN_PATH);
-        return reg;
+        if (nrt_Directory_exists(NITF_DEFAULT_PLUGIN_PATH))
+        {
+            strncpy(reg->path, NITF_DEFAULT_PLUGIN_PATH, NITF_MAX_PATH);
+            return reg;
+        }
+        else
+        {
+            fprintf(stderr,
+                    "Warning: Unable to find plugin path.\n"
+                    "Specify plugin location by setting environment variable "
+                    "%s, or by building the library from source\n",
+                    NITF_PLUGIN_PATH);
+            return reg;
+        }
     }
     else
     {
-        strcpy(reg->path, pluginEnvVar);
+        strncpy(reg->path, pluginEnvVar, NITF_MAX_PATH);
     }
     /*
      * If the we have a user-defined path, they might not