mruby error messages should be directed to stderr

2 files changed, 20 insertions, 4 deletions

diff --git a/src/backtrace.c b/src/backtrace.c
index f6e3e2eb0..d5d0818ae 100644
--- a/src/backtrace.c
+++ b/src/backtrace.c
@@ -17,7 +17,7 @@ mrb_print_backtrace(mrb_state *mrb)
   const char *filename, *method, *sep;
   int i, line;
 
-  printf("trace:\n");
+  fputs("trace:\n", stderr);
   ciidx = mrb_fixnum(mrb_obj_iv_get(mrb, mrb->exc, mrb_intern(mrb, "ciidx")));
   if (ciidx >= mrb->c->ciend - mrb->c->cibase)
     ciidx = 10; /* ciidx is broken... */
@@ -59,14 +59,14 @@ mrb_print_backtrace(mrb_state *mrb)
       const char *cn = mrb_class_name(mrb, ci->proc->target_class);
 
       if (cn) {
-        printf("\t[%d] %s:%d:in %s%s%s\n", i, filename, line, cn, sep, method);
+        fprintf(stderr, "\t[%d] %s:%d:in %s%s%s\n", i, filename, line, cn, sep, method);
       }
       else {
-        printf("\t[%d] %s:%d:in %s\n", i, filename, line, method);
+        fprintf(stderr, "\t[%d] %s:%d:in %s\n", i, filename, line, method);
       }
     }
     else {
-      printf("\t[%d] %s:%d\n", i, filename, line);
+      fprintf(stderr, "\t[%d] %s:%d\n", i, filename, line);
     }
   }
 #endif
diff --git a/src/print.c b/src/print.c
index 5367781f5..01c9b3cd0 100644
--- a/src/print.c
+++ b/src/print.c
@@ -35,6 +35,22 @@ mrb_p(mrb_state *mrb, mrb_value obj)
 }
 
 void
+mrb_print_error(mrb_state *mrb)
+{
+#ifdef ENABLE_STDIO
+  mrb_value s;
+  
+  mrb_print_backtrace(mrb);
+  s = mrb_funcall(mrb, mrb_obj_value(mrb->exc), "inspect", 0);
+  if (mrb_string_p(s)) {
+    struct RString *str = mrb_str_ptr(s);
+    fwrite(str->ptr, str->len, 1, stderr);
+    putc('\n', stderr);
+  }
+#endif
+}
+
+void
 mrb_show_version(mrb_state *mrb)
 {
   static const char version_msg[] = "mruby - Embeddable Ruby  Copyright (c) 2010-2013 mruby developers\n";