Implement a ring buffer switch duration:

when the new "Rotate capture file every n second(s)" checkbox or the
-b <# of file>[:<duration>] argument are used, [t]ethereal will skip to the
next ring buffer file if the specified duration has elapsed (even if the
specified capture size is not reached). This is useful when you want to have
separate capture files per hour or day for instance.

I let the autostop filesize parameter mandatory (i.e. the "rotate capture
file after n kilobytes") but this could be no longer strictly necessary when
that new feature is used ...

Another point: it might be interesting to really truncate the file at the
switch and not the closure ... According to user comments and my own real
case tests, I might plan to enhance this point and others (still ring buffer
related) in the future.

svn path=/trunk/; revision=7678

1 files changed, 5 insertions, 1 deletions

diff --git a/doc/tethereal.pod.template b/doc/tethereal.pod.template
index 71736beeb1..ce7fde353f 100644
--- a/doc/tethereal.pod.template
+++ b/doc/tethereal.pod.template
@@ -7,7 +7,7 @@ tethereal - Dump and analyze network traffic
 
 B<tethereal>
 S<[ B<-a> capture autostop condition ] ...>
-S<[ B<-b> number of ring buffer files ]>
+S<[ B<-b> number of ring buffer files [:duration] ]>
 S<[ B<-c> count ]>
 S<[ B<-D> ]>
 S<[ B<-f> capture filter expression ]>
@@ -155,6 +155,10 @@ point it'll discard the data in the first file and start writing to that
 file.  When that file fills up, B<Tethereal> will discard the data in
 the next file and start writing to it, and so on.
 
+If the optional duration is specified, B<Tethereal> will switch also 
+to the next file when the specified number of seconds has elapsed even
+if the current file is not completely fills up.
+
 When the capture completes, the files will be renamed to have names
 based on the number of the file and on the date and time at which
 packets most recently started being written to the file.