NAME

       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

       #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

       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.

       errbuf is a buffer large enough to hold at least PCAP_ERRBUF_SIZE chars.

RETURN VALUE

       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.

BACKWARD COMPATIBILITY

       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

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

                                                30 November 2023                        PCAP_OPEN_OFFLINE(3PCAP)