pcap_breakloop man page on GhostBSD

Man page or keyword search:  
man Server   9747 pages
apropos Keyword Search (all sections)
Output format
GhostBSD logo
[printable version]

PCAP_BREAKLOOP(3)					     PCAP_BREAKLOOP(3)

NAME
       pcap_breakloop - force a pcap_dispatch() or pcap_loop() call to return

SYNOPSIS
       #include <pcap/pcap.h>

       void pcap_breakloop(pcap_t *);

DESCRIPTION
       pcap_breakloop()	 sets  a  flag	that  will  force  pcap_dispatch()  or
       pcap_loop() to return rather than looping; they will return the	number
       of  packets  that  have been processed so far, or -2 if no packets have
       been processed so far.

       This routine is safe to use inside a signal handler on UNIX or  a  con‐
       sole  control  handler  on  Windows,  as	 it merely sets a flag that is
       checked within the loop.

       The flag is checked in loops reading packets from the OS - a signal  by
       itself will not necessarily terminate those loops - as well as in loops
       processing a set of packets returned by the OS.	Note that if  you  are
       catching	 signals  on UNIX systems that support restarting system calls
       after a signal, and calling pcap_breakloop() in the signal handler, you
       must specify, when catching those signals, that system calls should NOT
       be restarted by that signal.  Otherwise, if the	signal	interrupted  a
       call  reading  packets  in  a  live  capture,  when your signal handler
       returns after calling pcap_breakloop(), the call will be restarted, and
       the loop will not terminate until more packets arrive and the call com‐
       pletes.

       Note also that, in a  multi-threaded  application,  if  one  thread  is
       blocked	  in	pcap_dispatch(),    pcap_loop(),    pcap_next(),    or
       pcap_next_ex(), a call to pcap_breakloop() in a different  thread  will
       not unblock that thread; you will need to use whatever mechanism the OS
       provides for breaking a thread  out  of	blocking  calls	 in  order  to
       unblock the thread, such as thread cancellation in systems that support
       POSIX threads.

       Note that pcap_next() and pcap_next_ex() will, on some platforms,  loop
       reading	packets	 from the OS; that loop will not necessarily be termi‐
       nated by a signal, so pcap_breakloop()  should  be  used	 to  terminate
       packet processing even if pcap_next() or pcap_next_ex() is being used.

       pcap_breakloop()	 does  not  guarantee  that no further packets will be
       processed by pcap_dispatch() or pcap_loop() after it is called; at most
       one more packet might be processed.

       If  -2  is  returned  from  pcap_dispatch() or pcap_loop(), the flag is
       cleared, so a subsequent call will resume reading packets.  If a	 posi‐
       tive  number is returned, the flag is not cleared, so a subsequent call
       will return -2 and clear the flag.

SEE ALSO
       pcap(3), pcap_loop(3), pcap_next_ex(3)

				 5 April 2008		     PCAP_BREAKLOOP(3)
[top]

List of man pages available for GhostBSD

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net