diff --git a/include/picrin.h b/include/picrin.h
index 65b12a56..9da11089 100644
--- a/include/picrin.h
+++ b/include/picrin.h
@@ -4,6 +4,7 @@
 #include <stddef.h>
 #include <stdbool.h>
 #include <setjmp.h>
+#include <stdio.h>
 
 #include "picconf.h"
 #include "picrin/value.h"
@@ -76,7 +77,8 @@ pic_value pic_intern_cstr(pic_state *, const char *);
 pic_value pic_str_new(pic_state *, const char *, size_t);
 pic_value pic_str_new_cstr(pic_state *, const char *);
 
-bool pic_parse(pic_state *, const char *, pic_value *);
+bool pic_parse_file(pic_state *, FILE *file, pic_value *);
+bool pic_parse_cstr(pic_state *, const char *, pic_value *);
 
 pic_value pic_run(pic_state *, struct pic_proc *, pic_value);
 struct pic_proc *pic_codegen(pic_state *, pic_value);
diff --git a/src/parse.y b/src/parse.y
index fdf6247d..b51c175e 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -21,6 +21,7 @@ void yyerror(struct parser_control *, const char *);
 int yylex();
 int yylex_();
 void yylex_init();
+void yyset_in();
 void yy_scan_string();
 void yylex_destroy();
 %}
@@ -175,7 +176,31 @@ yylex(YYSTYPE *yylvalp, struct parser_control *p)
 }
 
 bool
-pic_parse(pic_state *pic, const char *str, pic_value *v)
+pic_parse_file(pic_state *pic, FILE *file, pic_value *v)
+{
+  struct parser_control p;
+
+  p.pic = pic;
+  p.incomp = false;
+  p.yynerrs = 0;
+
+  yylex_init(&p.yyscanner);
+  yyset_in(file, p.yyscanner);
+  yyparse(&p);
+  yylex_destroy(p.yyscanner);
+
+  if (p.yynerrs > 0) {
+    p.value = pic_undef_value();
+  }
+
+  if (! p.incomp) {
+    *v = p.value;
+  }
+  return ! p.incomp;
+}
+
+bool
+pic_parse_cstr(pic_state *pic, const char *str, pic_value *v)
 {
   struct parser_control p;
 
diff --git a/tools/main.c b/tools/main.c
index 0cbf46ff..fac9c432 100644
--- a/tools/main.c
+++ b/tools/main.c
@@ -95,7 +95,7 @@ main(int argc, char *argv[], char **envp)
     strcat(code, line);
 
     /* read */
-    r = pic_parse(pic, code, &v);
+    r = pic_parse_cstr(pic, code, &v);
     if (! r) {			/* wait for more input */
       goto next;
     }