Define bb_xgetlarg as a standard interface for extracting
numbers from getopt which includes careful error checking.
 -Erik
diff --git a/libbb/bb_xgetlarg.c b/libbb/bb_xgetlarg.c
new file mode 100644
index 0000000..598b0b3
--- /dev/null
+++ b/libbb/bb_xgetlarg.c
@@ -0,0 +1,28 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Copyright (C) 2003 Erik Andersen <andersee@debian.org>
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <errno.h>
+#include <assert.h>
+
+#include "busybox.h"
+
+extern long bb_xgetlarg(char *arg, int base, long lower, long upper)
+{
+	long result;
+	char *endptr;
+	int errno_save = errno;
+
+	assert(arg!=NULL);
+	errno = 0;
+	result = strtol(arg, &endptr, base);
+	if (errno != 0 || *endptr!='\0' || result < lower || result > upper)
+		show_usage();
+	errno = errno_save;
+	return result;
+}