| JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 1 | .\" @(#) $Header: /tcpdump/master/libpcap/pcap_open_live.3pcap,v 1.3 2008-04-06 02:53:22 guy Exp $ |
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| 22 | .TH PCAP_OPEN_LIVE 3PCAP "5 April 2008" |
| 23 | .SH NAME |
| 24 | pcap_open_live \- open a device for capturing |
| 25 | .SH SYNOPSIS |
| 26 | .nf |
| 27 | .ft B |
| 28 | #include <pcap/pcap.h> |
| 29 | .ft |
| 30 | .LP |
| 31 | .nf |
| 32 | .ft B |
| 33 | char errbuf[PCAP_ERRBUF_SIZE]; |
| 34 | .ft |
| 35 | .LP |
| 36 | .ft B |
| 37 | pcap_t *pcap_open_live(const char *device, int snaplen, |
| 38 | .ti +8 |
| 39 | int promisc, int to_ms, char *errbuf); |
| 40 | .ft |
| 41 | .fi |
| 42 | .SH DESCRIPTION |
| 43 | .B pcap_open_live() |
| 44 | is used to obtain a packet capture handle to look |
| 45 | at packets on the network. |
| 46 | .I device |
| 47 | is a string that specifies the network device to open; on Linux systems |
| 48 | with 2.2 or later kernels, a |
| 49 | .I device |
| 50 | argument of "any" or |
| 51 | .B NULL |
| 52 | can be used to capture packets from all interfaces. |
| 53 | .PP |
| 54 | .I snaplen |
| 55 | specifies the snapshot length to be set on the handle. |
| 56 | .PP |
| 57 | .I promisc |
| 58 | specifies if the interface is to be put into promiscuous mode. |
| 59 | .PP |
| 60 | .I to_ms |
| 61 | specifies the read timeout in milliseconds. |
| 62 | .SH RETURN VALUE |
| 63 | .B pcap_open_live() |
| 64 | returns a |
| 65 | .I 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 | .I errbuf |
| 75 | may also be set to warning text when |
| 76 | .B pcap_open_live() |
| 77 | succeeds; to detect this case the caller should store a zero-length string in |
| 78 | .I errbuf |
| 79 | before calling |
| 80 | .B pcap_open_live() |
| 81 | and display the warning to the user if |
| 82 | .I errbuf |
| 83 | is no longer a zero-length string. |
| 84 | .I errbuf |
| 85 | is assumed to be able to hold at least |
| 86 | .B PCAP_ERRBUF_SIZE |
| 87 | chars. |
| 88 | .SH SEE ALSO |
| 89 | pcap(3PCAP), pcap_create(3PCAP), pcap_activate(3PCAP) |