oracular (3) pcap_init.3pcap.gz

NAME

       pcap_init - initialize the library

SYNOPSIS

       #include <pcap/pcap.h>

       char errbuf[PCAP_ERRBUF_SIZE];

       int pcap_init(unsigned int opts, char *errbuf);

DESCRIPTION

       pcap_init()  is  used  to initialize the Packet Capture library.  opts specifies options for the library;
       errbuf is a buffer large enough to hold at least PCAP_ERRBUF_SIZE chars.

       Currently, the options that can be specified in opts are:

       PCAP_CHAR_ENC_LOCAL
              Treat all strings supplied as arguments, and return all strings to the caller,  as  being  in  the
              local character encoding.

       PCAP_CHAR_ENC_UTF_8
              Treat all strings supplied as arguments, and return all strings to the caller, as being in UTF-8.

       On  UNIX-like  systems,  the  local  character  encoding is assumed to be UTF-8, so no character encoding
       transformations are done.

       On Windows, the local character encoding is the local ANSI code page.

       If pcap_init() is not called, strings are treated as being in  the  local  ANSI  code  page  on  Windows,
       pcap_lookupdev(3PCAP) will succeed if there is a device on which to capture, and pcap_create(3PCAP) makes
       an attempt to check whether the string passed as an argument is  a  UTF-16LE  string  -  note  that  this
       attempt  is  unsafe,  as  it  may run past the end of the string - to handle pcap_lookupdev() returning a
       UTF-16LE string. Programs that don't call  pcap_init()  should,  on  Windows,  call  pcap_wsockinit()  to
       initialize  Winsock;  this  is  not  necessary  if  pcap_init() is called, as pcap_init() will initialize
       Winsock itself on Windows.

RETURN VALUE

       pcap_init() returns 0 on success and PCAP_ERROR on failure.  If PCAP_ERROR is returned, errbuf is  filled
       in with an appropriate error message.

BACKWARD COMPATIBILITY

       This  function  became available in libpcap release 1.9.0.  In previous releases, on Windows, all strings
       supplied as arguments, and all strings returned to the caller, are in the local character encoding.

SEE ALSO

       pcap(3PCAP)

                                                30 November 2023                                PCAP_INIT(3PCAP)