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  20 .TH PCAP_LOOKUPDEV 3PCAP "8 September 2017"
  21 .SH NAME
  22 pcap_lookupdev \- find the default device on which to capture
  23 .SH SYNOPSIS
  24 .nf
  25 .ft B
  26 #include <pcap/pcap.h>
  27 .ft
  28 .LP
  29 .nf
  30 .ft B
  31 char errbuf[PCAP_ERRBUF_SIZE];
  32 .ft
  33 .LP
  34 .ft B
  35 [DEPRECATED] char *pcap_lookupdev(char *errbuf);
  36 .ft
  37 .fi
  38 .SH DESCRIPTION
  39 .B This interface is obsoleted by
  40 .BR pcap_findalldevs (3PCAP).
  41 To find a default device on which to capture, call
  42 .BR pcap_findalldevs ()
  43 and, if the list it returns is not empty, use the first device in the
  44 list.  (If the list is empty, there are no devices on which capture is
  45 possible.)
  46 .LP
  47 .BR pcap_lookupdev ()
  48 returns a pointer to a string giving the name of a network device
  49 suitable for use with
  50 .BR pcap_create (3PCAP)
  51 and
  52 .BR \%pcap_activate (3PCAP),
  53 or with
  54 .BR pcap_open_live (3PCAP),
  55 and with
  56 .BR pcap_lookupnet (3PCAP).
  57 If there is an error,
  58 .B NULL
  59 is returned and
  60 .I errbuf
  61 is filled in with an appropriate error message.
  62 .I errbuf
  63 is assumed to be able to hold at least
  64 .B PCAP_ERRBUF_SIZE
  65 chars.
  66 .SH SEE ALSO
  67 .BR pcap (3PCAP)
  68 .SH BUGS
  69 The pointer returned by
  70 .BR pcap_lookupdev ()
  71 points to a static buffer; subsequent calls to
  72 .BR pcap_lookupdev ()
  73 in the same thread, or calls to
  74 .BR pcap_lookupdev ()
  75 in another thread, may overwrite that buffer.
  76 .LP
  77 In WinPcap, this function may return a UTF-16 string rather than an
  78 ASCII or UTF-8 string.
  79