diff --git a/build-aux/configure-lib.sh b/build-aux/configure-lib.sh
index eb320a66..dd585840 100644
--- a/build-aux/configure-lib.sh
+++ b/build-aux/configure-lib.sh
@@ -250,6 +250,7 @@ lib/stdio/fclose.c
 lib/stdio/fdopen.c
 lib/stdio/ferror.c
 lib/stdio/fflush.c
+lib/stdio/fileno.c
 lib/stdio/fopen.c
 lib/stdio/fprintf.c
 lib/stdio/fread.c
@@ -334,7 +335,6 @@ lib/posix/unsetenv.c
 lib/stdio/clearerr.c
 lib/stdio/feof.c
 lib/stdio/fgets.c
-lib/stdio/fileno.c
 lib/stdio/freopen.c
 lib/stdio/fscanf.c
 lib/stdio/perror.c
diff --git a/include/stdio.h b/include/stdio.h
index c68576e0..9b371ba3 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -65,6 +65,7 @@ int ferror (FILE * stream);
 int fflush (FILE * stream);
 int fgetc (FILE * stream);
 char *fgets (char *s, int size, FILE * stream);
+int fileno (FILE *);
 int fpurge (FILE * stream);
 int fputc (int c, FILE * stream);
 int fputs (char const *s, FILE * stream);
diff --git a/lib/stdio/vfprintf.c b/lib/stdio/vfprintf.c
index 0b2c30a0..b87479ba 100644
--- a/lib/stdio/vfprintf.c
+++ b/lib/stdio/vfprintf.c
@@ -26,7 +26,7 @@
 int
 vfprintf (FILE * f, char const *format, va_list ap)
 {
-  int fd = (long) f;
+  int fd = fileno (f);
   char const *p = format;
   int count = 0;
   while (*p)
@@ -41,6 +41,7 @@ vfprintf (FILE * f, char const *format, va_list ap)
         char c = *p;
         int left_p = 0;
         int precision = -1;
+        int prefix_p = 0;
         int width = -1;
         if (c == '-')
           {
@@ -51,12 +52,17 @@ vfprintf (FILE * f, char const *format, va_list ap)
         if (c == ' ')
           {
             pad = c;
-            c = *p++;
+            c = *++p;
+          }
+        if (c == '#')
+          {
+            prefix_p = 1;
+            c = *++p;
           }
         if (c == '0')
           {
             pad = c;
-            c = *p++;
+            c = *++p;
           }
         if (c >= '0' && c <= '9')
           {
@@ -134,6 +140,18 @@ vfprintf (FILE * f, char const *format, va_list ap)
                       count++;
                     }
                 }
+              if (prefix_p && *s && c == 'o')
+                {
+                  fputc ('0', f);
+                  width--;
+                }
+              if (prefix_p && *s && (c == 'x' || c == 'X'))
+                {
+                  fputc ('0', f);
+                  width--;
+                  fputc ('x', f);
+                  width--;
+                }
               while (*s)
                 {
                   if (precision-- <= 0)
@@ -194,6 +212,9 @@ vfprintf (FILE * f, char const *format, va_list ap)
           case 'G':
             {
               double d = va_arg8 (ap, double);
+#if 1
+              fputs ("0.0", f);
+#else
               char *s = dtoab (d, 10, 1);
               if (c == 'E' || c == 'G')
                 strupr (s);
@@ -229,6 +250,7 @@ vfprintf (FILE * f, char const *format, va_list ap)
                   fputc (pad, f);
                   count++;
                 }
+#endif
               break;
             }
           case 'n':
@@ -241,6 +263,8 @@ vfprintf (FILE * f, char const *format, va_list ap)
             {
               eputs ("vfprintf: not supported: %:");
               eputc (c);
+              eputs (", in format: ");
+              eputs (format);
               eputs ("\n");
               p++;
             }
@@ -248,5 +272,5 @@ vfprintf (FILE * f, char const *format, va_list ap)
         p++;
       }
   va_end (ap);
-  return 0;
+  return count;
 }
diff --git a/lib/stdio/vfscanf.c b/lib/stdio/vfscanf.c
index b1083a56..fe12649d 100644
--- a/lib/stdio/vfscanf.c
+++ b/lib/stdio/vfscanf.c
@@ -110,6 +110,8 @@ vfscanf (FILE * stream, char const *template, va_list ap)
             {
               eputs ("vsscanf: not supported: %:");
               eputc (c);
+              eputs (", in template: ");
+              eputs (template);
               eputs ("\n");
               t++;
               p = fgetc (stream);
diff --git a/lib/stdio/vsnprintf.c b/lib/stdio/vsnprintf.c
index 9a8d796d..c524d223 100644
--- a/lib/stdio/vsnprintf.c
+++ b/lib/stdio/vsnprintf.c
@@ -43,6 +43,7 @@ vsnprintf (char *str, size_t size, char const *format, va_list ap)
         c = *p;
         int left_p = 0;
         int precision = -1;
+        int prefix_p = 0;
         int width = -1;
         if (c == '-')
           {
@@ -53,12 +54,17 @@ vsnprintf (char *str, size_t size, char const *format, va_list ap)
         if (c == ' ')
           {
             pad = c;
-            c = *p++;
+            c = *++p;
+          }
+        if (c == '#')
+          {
+            prefix_p = 1;
+            c = *++p;
           }
         if (c == '0')
           {
             pad = c;
-            c = *p++;
+            c = *++p;
           }
         if (c >= '0' && c <= '9')
           {
@@ -142,6 +148,18 @@ vsnprintf (char *str, size_t size, char const *format, va_list ap)
                       count++;
                     }
                 }
+              if (prefix_p && *s && c == 'o')
+                {
+                  *s++ = '0';
+                  width--;
+                }
+              if (prefix_p && *s && (c == 'x' || c == 'X'))
+                {
+                  *s++ = '0';
+                  width--;
+                  *s++ = 'x';
+                  width--;
+                }
               while (*s)
                 {
                   if (precision-- <= 0)
@@ -210,6 +228,11 @@ vsnprintf (char *str, size_t size, char const *format, va_list ap)
           case 'G':
             {
               double d = va_arg8 (ap, double);
+#if 1
+              *str++ = '0';
+              *str++ = '.';
+              *str++ = '0';
+#else
               char *s = dtoab (d, 10, 1);
               if (c == 'E' || c == 'G')
                 strupr (s);
@@ -250,6 +273,7 @@ vsnprintf (char *str, size_t size, char const *format, va_list ap)
                     *str++ = pad;
                   count++;
                 }
+#endif
               break;
             }
           case 'n':
@@ -262,6 +286,8 @@ vsnprintf (char *str, size_t size, char const *format, va_list ap)
             {
               eputs ("vsnprintf: not supported: %:");
               eputc (c);
+              eputs (", in format: ");
+              eputs (format);
               eputs ("\n");
               p++;
             }
diff --git a/lib/stdio/vsscanf.c b/lib/stdio/vsscanf.c
index 4573bc01..a42b0dba 100644
--- a/lib/stdio/vsscanf.c
+++ b/lib/stdio/vsscanf.c
@@ -81,6 +81,8 @@ vsscanf (char const *s, char const *template, va_list ap)
             {
               eputs ("vsscanf: not supported: %:");
               eputc (c);
+              eputs (", in template: ");
+              eputs (template);
               eputs ("\n");
               t++;
               p++;