July 26, 2006 BLUETOOTH 3

### NAME

bt_gethostbyname, bt_gethostbyaddr, bt_gethostent, bt_sethostent, bt_endhostent, bt_getprotobyname, bt_getprotobynumber, bt_getprotoent, bt_setprotoent, bt_endprotoent, bt_aton, bt_ntoa, bt_devaddr, bt_devname, - Bluetooth routines

### LIBRARY

Bluetooth Hosts Library (libbluetooth, -lbluetooth)

### SYNOPSIS

```struct` `hostent``*` bt_gethostbyname(```const char *name`)
```struct` `hostent``*` bt_gethostbyaddr(```const char *addr``, int len``, int type`)
```struct` `hostent``*` bt_gethostent(```void`)
```void` bt_sethostent(```int stayopen`)
```void` bt_endhostent(```void`)
```struct` `protoent``*` bt_getprotobyname(```const char *name`)
```struct` `protoent``*` bt_getprotobynumber(```int proto`)
```struct` `protoent``*` bt_getprotoent(```void`)
```void` bt_setprotoent(```int stayopen`)
```void` bt_endprotoent(```void`)
```int` bt_aton(```const char *str``, bdaddr_t *ba`)
```const` `char``*` bt_ntoa(```const bdaddr_t *ba``, char *str`)
```int` bt_devaddr(```const char *name``, bdaddr_t *addr`)
```int` bt_devname(```char *name``, const bdaddr_t *addr`)

### DESCRIPTION

The bt_gethostent(``), bt_gethostbyname(``), and bt_gethostbyaddr(``) functions each return a pointer to an object with the structure describing a Bluetooth host referenced by name or by address, respectively.

The ```name` argument passed to bt_gethostbyname(``) should point to a ```NUL`-terminated hostname. The ```addr` argument passed to bt_gethostbyaddr(``) should point to an address which is ```len` bytes long, in binary form (i.e., not a Bluetooth BD_ADDR in human readable ASCII form). The ```type` argument specifies the address family of this address and must be set to ```AF_BLUETOOTH`.

The structure returned contains the information obtained from a line in ```/etc/bluetooth/hosts` file.

The bt_sethostent(``) function controls whether ```/etc/bluetooth/hosts` file should stay open after each call to bt_gethostbyname(``) or bt_gethostbyaddr(``). If the ```stayopen` flag is non-zero, the file will not be closed.

The bt_endhostent(``) function closes the ```/etc/bluetooth/hosts` file.

The bt_getprotoent(``), bt_getprotobyname(``), and bt_getprotobynumber(``) functions each return a pointer to an object with the structure describing a Bluetooth Protocol Service Multiplexor referenced by name or number, respectively.

The ```name` argument passed to bt_getprotobyname(``) should point to a ```NUL`-terminated Bluetooth Protocol Service Multiplexor name. The ```proto` argument passed to bt_getprotobynumber(``) should have numeric value of the desired Bluetooth Protocol Service Multiplexor.

The structure returned contains the information obtained from a line in ```/etc/bluetooth/protocols` file.

The bt_setprotoent(``) function controls whether ```/etc/bluetooth/protocols` file should stay open after each call to bt_getprotobyname(``) or bt_getprotobynumber(``). If the ```stayopen` flag is non-zero, the file will not be closed.

The bt_endprotoent(``) function closes the ```/etc/bluetooth/protocols` file.

The bt_aton(``) routine interprets the specified character string as a Bluetooth address, placing the address into the structure provided. It returns 1 if the string was successfully interpreted, or 0 if the string is invalid.

The routine bt_ntoa(``) takes a Bluetooth address and places an ASCII string representing the address into the buffer provided. It is up to the caller to ensure that provided buffer has enough space. If no buffer was provided then an internal static buffer will be used.

The bt_devaddr(``) function interprets the specified character string as the address or device name of a Bluetooth device on the local system, and places the device address in the structure provided, if any. It returns 1 if the string was successfully interpreted, or 0 if the string did not match any local device. The bt_devname(``) function takes a Bluetooth device address and copies the local device name associated with that address into the buffer provided, if any. It returns 1 when the device was found, otherwise 0.

### FILES

```/etc/bluetooth/hosts`
```/etc/bluetooth/protocols`

### EXAMPLES

Print out the hostname associated with a specific BD_ADDR:

  `

      const char *bdstr = "00:01:02:03:04:05";
      bdaddr_t bd;
      struct hostent *hp;

      if (!bt_aton(bdstr, &bd))
              errx(1, "can't parse BD_ADDR %s", bdstr);

      if ((hp = bt_gethostbyaddr((const char *)&bd,
          sizeof(bd), AF_BLUETOOTH)) == NULL)
              errx(1, "no name associated with %s", bdstr);

      printf("name associated with %s is %s\n", bdstr, hp->h_name);

  `

### DIAGNOSTICS

Error return status from bt_gethostent(``), bt_gethostbyname(``), and bt_gethostbyaddr(``) is indicated by return of a ```NULL` pointer. The external integer h_errno may then be checked to see whether this is a temporary failure or an invalid or unknown host. The routine herror(3) can be used to print an error message describing the failure. If its argument ```string` is non-```NULL`, it is printed, followed by a colon and a space. The error message is printed with a trailing newline.

The variable h_errno can have the following values:

```HOST_NOT_FOUND`
  No such host is known.

```NO_RECOVERY`
  Some unexpected server failure was encountered. This is a non-recoverable error.

The bt_getprotoent(``), bt_getprotobyname(``), and bt_getprotobynumber(``) return ```NULL` on EOF or error.

### SEE ALSO

gethostbyaddr(3), gethostbyname(3), getprotobyname(3), getprotobynumber(3), herror(3), inet_aton(3), inet_ntoa(3)

### HISTORY

libbluetooth first appeared in FreeBSD was ported to NetBSD4.0 and extended by Iain Hibbert
for Itronix, Inc.

### AUTHORS

Maksim Yevmenkin <m_evmenkin@yahoo.com>
Iain Hibbert

### CAVEATS

The bt_gethostent(``) function reads the next line of ```/etc/bluetooth/hosts`, opening the file if necessary.

The bt_sethostent(``) function opens and/or rewinds the ```/etc/bluetooth/hosts` file.

The bt_getprotoent(``) function reads the next line of ```/etc/bluetooth/protocols`, opening the file if necessary.

The bt_setprotoent(``) function opens and/or rewinds the ```/etc/bluetooth/protocols` file.

### BUGS

These functions use static data storage; if the data is needed for future use, it should be copied before any subsequent calls overwrite it.