Hi I think I've found a version 30 from Debian's archive - the essid string is fixed length, rather than sized by essid_len (even though essid_len is now in the struct). Is this the same as the version you have? /* Structure for storing all wireless information for each device * This is a cut down version of the one above, containing only * the things *truly* needed to configure a card. * Don't add other junk, I'll remove it... */ typedef struct wireless_config { char name[IFNAMSIZ + 1]; /* Wireless/protocol name */ int has_nwid; iwparam nwid; /* Network ID */ int has_freq; double freq; /* Frequency/channel */ int freq_flags; int has_key; unsigned char key[IW_ENCODING_TOKEN_MAX]; /* Encoding key used */ int key_size; /* Number of bytes */ int key_flags; /* Various flags */ int has_essid; int essid_on; char essid[IW_ESSID_MAX_SIZE + 2]; /* ESSID (extended network) */ int essid_len; int has_mode; int mode; /* Operation mode */ } wireless_config; Best wishes Stephen