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 pcap-ng file format, although not all pcap-ng 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¶
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.
SEE ALSO¶
pcap(3PCAP),
pcap-savefile(5)