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 "11 March 2025"
  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 capture packets on a device
  41 (typically a network interface, see
  42 .BR \%pcap_findalldevs (3PCAP)
  43 for a more detailed explanation).
  44 .I source
  45 is a string that specifies the capture device to open, in this function
  46 .B NULL
  47 means the same as the string "any".
  48 .I errbuf
  49 is a buffer large enough to hold at least
  50 .B PCAP_ERRBUF_SIZE
  51 chars.
  52 .PP
  53 The returned handle must be activated with
  54 .BR pcap_activate (3PCAP)
  55 before packets can be captured
  56 with it; options for the capture, such as promiscuous mode, can be set
  57 on the handle before activating it.
  58 .SH RETURN VALUE
  59 .BR pcap_create ()
  60 returns a
  61 .B pcap_t *
  62 on success and
  63 .B NULL
  64 on failure.
  65 If
  66 .B NULL
  67 is returned,
  68 .I errbuf
  69 is filled in with an appropriate error message.
  70 .SH SEE ALSO
  71 .BR pcap (3PCAP)