focal (3) pcap_dump_open.3pcap.gz

NAME

       pcap_dump_open, pcap_dump_fopen - open a file to which to write packets

SYNOPSIS

       #include <pcap/pcap.h>

       pcap_dumper_t *pcap_dump_open(pcap_t *p, const char *fname);
       pcap_dumper_t *pcap_dump_open_append(pcap_t *p, const char *fname);
       pcap_dumper_t *pcap_dump_fopen(pcap_t *p, FILE *fp);

DESCRIPTION

       pcap_dump_open()  is  called to open a ``savefile'' for writing.  fname specifies the name of the file to
       open. The file will have the same format as those used by tcpdump(1) and tcpslice(1).  The name "-" is  a
       synonym for stdout.

       pcap_dump_fopen()  is called to write data to an existing open stream fp; this stream will be closed by a
       subsequent call to pcap_dump_close(3PCAP).  Note that on Windows, that stream should be opened in  binary
       mode.

       p  is a capture or ``savefile'' handle returned by an earlier call to pcap_create(3PCAP) and activated by
       an earlier call to pcap_activate(3PCAP), or returned by  an  earlier  call  to  pcap_open_offline(3PCAP),
       pcap_open_live(3PCAP), or pcap_open_dead(3PCAP).  The time stamp precision, link-layer type, and snapshot
       length from p are used as the link-layer type and snapshot length of the output file.

       pcap_dump_open_append() is like pcap_dump_open() but does not create the file if it does not  exist  and,
       if  it  does already exist, and is a pcap file with the same byte order as the host opening the file, and
       has the same time stamp precision, link-layer header type, and snapshot length as p, it  will  write  new
       packets at the end of the file.

RETURN VALUES

       A  pointer  to a pcap_dumper_t structure to use in subsequent pcap_dump(3PCAP) and pcap_dump_close(3PCAP)
       calls is returned on success.  NULL is returned on failure.  If NULL is returned, pcap_geterr(3PCAP)  can
       be used to get the error text.

BACKWARD COMPATIBILITY

       The  pcap_dump_open_append()  function  became available in libpcap release 1.7.2.  In previous releases,
       there is no support for appending packets to an existing savefile.

SEE ALSO

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

                                                 22 August 2018                            PCAP_DUMP_OPEN(3PCAP)