This will make Thomas happy! :D

cellular_automaton/wireworld_c/configuration.c

@@ -29,6 +29,8 @@ long parse_long(const char *str);
 
 int log_enabled(const conf_t *c, int lvl);
 
+void chop_wi_extension(char *filename);
+
 // ==========================================================================
 
 void conf_init_default(conf_t *c)
@@ -103,6 +105,7 @@ void conf_init_from_args(conf_t *c, int argc, char* argv[])
    }
 
    strncpy(c->file_basename, argv[optind], sizeof(c->file_basename));
+   chop_wi_extension(c->file_basename);
 
    conf_set_or_validate_nprocs(c);
 }
@@ -180,3 +183,18 @@ long parse_long(const char *str)
    return result;
 }
 
+void chop_wi_extension(char *filename)
+{
+   char *extension = strrchr(filename, '.');
+   if(extension != NULL) {
+      if(strcmp(extension, FILE_EXT) == 0) {
+         *extension = '\0';
+      } else {
+         fprintf(stderr,
+            "Input file '%s' does not have expected file extension '%s'.\n",
+            filename, FILE_EXT
+         );
+         MPI_Abort(MPI_COMM_WORLD, EXIT_FAILURE);
+      }
+   }
+}