Index: uspace/lib/c/generic/str.c
===================================================================
--- uspace/lib/c/generic/str.c	(revision 0030eef187b4b4a1af1fe738a6c7c95f7c5cc95f)
+++ uspace/lib/c/generic/str.c	(revision 560d79ff73b54aa14113d7a5215931b4a9443e94)
@@ -259,4 +259,41 @@
 	
 	return offset;
+}
+
+/** Get size of string with size limit.
+ *
+ * Get the number of bytes which are used by the string @a str
+ * (excluding the NULL-terminator), but no more than @max_size bytes.
+ *
+ * @param str      String to consider.
+ * @param max_size Maximum number of bytes to measure.
+ *
+ * @return Number of bytes used by the string
+ *
+ */
+size_t str_nsize(const char *str, size_t max_size)
+{
+	size_t size = 0;
+	
+	while ((*str++ != 0) && (size < max_size))
+		size++;
+	
+	return size;
+}
+
+/** Get size of wide string with size limit.
+ *
+ * Get the number of bytes which are used by the wide string @a str
+ * (excluding the NULL-terminator), but no more than @max_size bytes.
+ *
+ * @param str      Wide string to consider.
+ * @param max_size Maximum number of bytes to measure.
+ *
+ * @return Number of bytes used by the wide string
+ *
+ */
+size_t wstr_nsize(const wchar_t *str, size_t max_size)
+{
+	return (wstr_nlength(str, max_size) * sizeof(wchar_t));
 }
 
Index: uspace/lib/c/include/str.h
===================================================================
--- uspace/lib/c/include/str.h	(revision 0030eef187b4b4a1af1fe738a6c7c95f7c5cc95f)
+++ uspace/lib/c/include/str.h	(revision 560d79ff73b54aa14113d7a5215931b4a9443e94)
@@ -60,4 +60,7 @@
 extern size_t str_size(const char *str);
 extern size_t wstr_size(const wchar_t *str);
+
+extern size_t str_nsize(const char *str, size_t max_size);
+extern size_t wstr_nsize(const wchar_t *str, size_t max_size);
 
 extern size_t str_lsize(const char *str, size_t max_len);