pcap_open_offline_with_tstamp_precision(3pcap) — Linux manual page


PCAP_OPEN_OFFLINE(3PCAP)                            PCAP_OPEN_OFFLINE(3PCAP)

NAME         top

       pcap_open_offline,           pcap_open_offline_with_tstamp_precision,
       pcap_fopen_offline, pcap_fopen_offline_with_tstamp_precision - open a
       saved capture file for reading

SYNOPSIS         top

       #include <pcap/pcap.h>

       char errbuf[PCAP_ERRBUF_SIZE];

       pcap_t *pcap_open_offline(const char *fname, char *errbuf);
       pcap_t *pcap_open_offline_with_tstamp_precision(const char *fname,
           u_int precision, char *errbuf);
       pcap_t *pcap_fopen_offline(FILE *fp, char *errbuf);
       pcap_t *pcap_fopen_offline_with_tstamp_precision(FILE *fp,
           u_int precision, char *errbuf);

DESCRIPTION         top

       pcap_open_offline() and pcap_open_offline_with_tstamp_precision() are
       called to open a ``savefile'' for reading.

       fname specifies the name of the file to open. The file can have the
       pcap file format as described in pcap-savefile(5), which is the file
       format used by, among other programs, tcpdump(1) and tcpslice(1), or
       can have the pcapng file format, although not all pcapng files can be
       read.  The name "-" is a synonym for stdin.

       pcap_open_offline_with_tstamp_precision() takes an additional
       precision argument specifying the time stamp precision desired; if
       PCAP_TSTAMP_PRECISION_MICRO is specified, packet time stamps will be
       supplied in seconds and microseconds, and if
       PCAP_TSTAMP_PRECISION_NANO is specified, packet time stamps will be
       supplied in seconds and nanoseconds.  If the time stamps in the file
       do not have the same precision as the requested precision, they will
       be scaled up or down as necessary before being supplied.

       Alternatively, you may call pcap_fopen_offline() or
       pcap_fopen_offline_with_tstamp_precision() to read dumped data from
       an existing open stream fp.
       pcap_fopen_offline_with_tstamp_precision() takes an additional
       precision argument as described above.  Note that on Windows, that
       stream should be opened in binary mode.

RETURN VALUE         top

       pcap_open_offline(), pcap_open_offline_with_tstamp_precision(),
       pcap_fopen_offline(), and pcap_fopen_offline_with_tstamp_precision()
       return a pcap_t * on success and NULL on failure.  If NULL is
       returned, errbuf is filled in with an appropriate error message.
       errbuf is assumed to be able to hold at least PCAP_ERRBUF_SIZE chars.


       pcap_open_offline_with_tstamp_precision() and
       pcap_fopen_offline_with_tstamp_precision() became available in
       libpcap release 1.5.1.  In previous releases, time stamps from a
       savefile are always given in seconds and microseconds.

SEE ALSO         top

       pcap(3PCAP), pcap-savefile(5)

COLOPHON         top

       This page is part of the libpcap (packet capture library) project.
       Information about the project can be found at 
       ⟨http://www.tcpdump.org/⟩.  If you have a bug report for this manual
       page, see ⟨http://www.tcpdump.org/#patches⟩.  This page was obtained
       from the project's upstream Git repository
       ⟨https://github.com/the-tcpdump-group/libpcap.git⟩ on 2020-09-18.
       (At that time, the date of the most recent commit that was found in
       the repository was 2020-09-15.)  If you discover any rendering prob‐
       lems in this HTML version of the page, or you believe there is a bet‐
       ter or more up-to-date source for the page, or you have corrections
       or improvements to the information in this COLOPHON (which is not
       part of the original manual page), send a mail to man-pages@man7.org

                               23 August 2018       PCAP_OPEN_OFFLINE(3PCAP)