new file mode 100644
--- /dev/null
+++ b/lib/xstrtol.c
@@ -0,0 +1,139 @@
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#ifdef STDC_HEADERS
+#include <stdlib.h>
+#else
+long int __strtol (const char *, char **, int base);
+#endif
+
+#include <assert.h>
+/* FIXME: define NDEBUG before release.  */
+
+#include <errno.h>
+#ifndef errno
+extern int errno;
+#endif
+
+#if HAVE_LIMITS_H
+#include <limits.h>
+#endif
+
+#ifndef ULONG_MAX
+#define ULONG_MAX ((unsigned long) ~(unsigned long) 0)
+#endif
+
+#ifndef LONG_MAX
+#define LONG_MAX ((long int) (ULONG_MAX >> 1))
+#endif
+
+#include "xstrtol.h"
+
+__unsigned long int __strtol ();
+
+/* FIXME: comment.  */
+
+strtol_error
+__xstrtol (s, ptr, base, val, allow_bkm_suffix)
+     const char *s;
+     char **ptr;
+     int base;
+     __unsigned long int *val;
+     int allow_bkm_suffix;
+{
+  char *t_ptr;
+  char **p;
+  __unsigned long int tmp;
+
+  assert (0 <= base && base <= 36);
+
+  p = (ptr ? ptr : &t_ptr);
+
+  errno = 0;
+  tmp = __strtol (s, p, base);
+  if (errno != 0)
+    return LONGINT_OVERFLOW;
+  if (*p == s)
+    return LONGINT_INVALID;
+  if (!allow_bkm_suffix)
+    {
+      if (**p == '\0')
+	{
+	  *val = tmp;
+	  return LONGINT_OK;
+	}
+      else
+	return LONGINT_INVALID_SUFFIX_CHAR;
+    }
+
+  switch (**p)
+    {
+    case '\0':
+      break;
+
+#define BKM_SCALE(x, scale_factor, error_return)			\
+      do								\
+	{								\
+	  if ((x) > (double) __ZLONG_MAX / (scale_factor))		\
+	    return (error_return);					\
+	  (x) *= (scale_factor);					\
+	}								\
+      while (0)
+
+    case 'b':
+      BKM_SCALE (tmp, 512, LONGINT_OVERFLOW);
+      ++(*p);
+      break;
+
+    case 'k':
+      BKM_SCALE (tmp, 1024, LONGINT_OVERFLOW);
+      ++(*p);
+      break;
+
+    case 'm':
+      BKM_SCALE (tmp, 1024 * 1024, LONGINT_OVERFLOW);
+      ++(*p);
+      break;
+
+    default:
+      return LONGINT_INVALID_SUFFIX_CHAR;
+      break;
+    }
+
+  *val = tmp;
+  return LONGINT_OK;
+}
+
+#ifdef TESTING_XSTRTO
+
+#include <stdio.h>
+#include "error.h"
+
+char *program_name;
+
+int
+main (int argc, char** argv)
+{
+  strtol_error s_err;
+  int i;
+
+  program_name = argv[0];
+  for (i=1; i<argc; i++)
+    {
+      char *p;
+      __unsigned long int val;
+
+      s_err = __xstrtol (argv[i], &p, 0, &val, 1);
+      if (s_err == LONGINT_OK)
+	{
+	  printf ("%s->%lu (%s)\n", argv[i], val, p);
+	}
+      else
+	{
+	  STRTOL_FATAL_ERROR (argv[i], "arg", s_err);
+	}
+    }
+  exit (0);
+}
+#endif /* TESTING_XSTRTO */

new file mode 100644
--- /dev/null
+++ b/lib/xstrtol.h
@@ -0,0 +1,57 @@
+#ifndef _xstrtol_h_
+#define _xstrtol_h_ 1
+
+#if STRING_TO_UNSIGNED
+# define __xstrtol xstrtoul
+# define __strtol strtoul
+# define __unsigned unsigned
+# define __ZLONG_MAX ULONG_MAX
+#else
+# define __xstrtol xstrtol
+# define __strtol strtol
+# define __unsigned /* empty */
+# define __ZLONG_MAX LONG_MAX
+#endif
+
+#if defined (__STDC__) && __STDC__
+#define	__P(x) x
+#else
+#define	__P(x) ()
+#endif
+
+enum strtol_error
+  {
+    LONGINT_OK, LONGINT_INVALID, LONGINT_INVALID_SUFFIX_CHAR, LONGINT_OVERFLOW
+  };
+typedef enum strtol_error strtol_error;
+
+strtol_error
+  __xstrtol __P ((const char *s, char **ptr, int base,
+		  __unsigned long int *val, int allow_bkm_suffix));
+
+#define STRTOL_FATAL_ERROR(str, argument_type_string, err)		\
+  do									\
+    {									\
+      switch ((err))							\
+	{								\
+	case LONGINT_OK:						\
+	  abort ();							\
+									\
+	case LONGINT_INVALID:						\
+	  error (2, 0, "invalid %s `%s'", (argument_type_string), (str));\
+	  break;							\
+									\
+	case LONGINT_INVALID_SUFFIX_CHAR:				\
+	  error (2, 0, "invalid character following %s `%s'",		\
+		 (argument_type_string), (str));			\
+	  break;							\
+									\
+	case LONGINT_OVERFLOW:						\
+	  error (2, 0, "%s `%s' larger than maximum long int",		\
+		 (argument_type_string), (str));			\
+	  break;							\
+	}								\
+    }									\
+  while (0)
+
+#endif /* _xstrtol_h_ */

new file mode 100644
--- /dev/null
+++ b/lib/xstrtoul.c
@@ -0,0 +1,2 @@
+#define STRING_TO_UNSIGNED 1
+#include "xstrtol.c"

new file mode 100644
--- /dev/null
+++ b/lib/xstrtoul.h
@@ -0,0 +1,7 @@
+#ifndef _xstrtoul_h_
+#define _xstrtoul_h_ 1
+
+#define STRING_TO_UNSIGNED 1
+#include "xstrtol.h"
+
+#endif /* _xstrtoul_h_ */