blkid_encode_string ()
int
blkid_encode_string (const char *str,
                     char *str_enc,
                     size_t len);
Encode all potentially unsafe characters of a string to the
corresponding hex value prefixed by '\x'.
Returns
 0 if the entire string was copied, non-zero otherwise.
 
 
blkid_safe_string ()
int
blkid_safe_string (const char *str,
                   char *str_safe,
                   size_t len);
Processing whitespace characters. Allows valid ascii,valid utf8.
Replace everything else with'_'
Returns
 0 on success or -1 in case of error.