The Tcpdump Group git mirrors - libpcap/blob - pcap_create.3pcap

   1 .\" Copyright (c) 1994, 1996, 1997
   2 .\"     The Regents of the University of California.  All rights reserved.
   3 .\"
   4 .\" Redistribution and use in source and binary forms, with or without
   5 .\" modification, are permitted provided that: (1) source code distributions
   6 .\" retain the above copyright notice and this paragraph in its entirety, (2)
   7 .\" distributions including binary code include the above copyright notice and
   8 .\" this paragraph in its entirety in the documentation or other materials
   9 .\" provided with the distribution, and (3) all advertising materials mentioning
  10 .\" features or use of this software display the following acknowledgement:
  11 .\" ``This product includes software developed by the University of California,
  12 .\" Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  13 .\" the University nor the names of its contributors may be used to endorse
  14 .\" or promote products derived from this software without specific prior
  15 .\" written permission.
  16 .\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  17 .\" WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  18 .\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  19 .\"
  20 .TH PCAP_CREATE 3PCAP "6 September 2024"
  21 .SH NAME
  22 pcap_create \- create a live capture handle
  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 pcap_t *pcap_create(const char *source, char *errbuf);
  36 .ft
  37 .fi
  38 .SH DESCRIPTION
  39 .BR pcap_create ()
  40 is used to create a packet capture handle to look
  41 at packets on the network.
  42 .I source
  43 is a string that specifies the network device to open; on all supported Linux
  44 systems, as well as on recent versions of macOS and Solaris, a
  45 .I source
  46 argument of "any" or
  47 .B NULL
  48 can be used to capture packets from all network interfaces.  The latter should
  49 not be confused with all available capture devices as seen by
  50 .BR pcap_findalldevs (3PCAP),
  51 which may also include D-Bus, USB etc.
  52 .I errbuf
  53 is a buffer large enough to hold at least
  54 .B PCAP_ERRBUF_SIZE
  55 chars.
  56 .PP
  57 The returned handle must be activated with
  58 .BR pcap_activate (3PCAP)
  59 before packets can be captured
  60 with it; options for the capture, such as promiscuous mode, can be set
  61 on the handle before activating it.
  62 .SH RETURN VALUE
  63 .BR pcap_create ()
  64 returns a
  65 .B pcap_t *
  66 on success and
  67 .B NULL
  68 on failure.
  69 If
  70 .B NULL
  71 is returned,
  72 .I errbuf
  73 is filled in with an appropriate error message.
  74 .SH SEE ALSO
  75 .BR pcap (3PCAP)