netsniff-ng: Rotate pcap files prematurely on SIGHUP

Allow to send SIGHUP to a running netsniff-ng process, causing it to
prematurely rotate the output PCAP when the output device (-o/--out) is
a directory. The rotating interval (time/file size) will be reset.

Suggested by dcode in #140

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

1 files changed, 8 insertions, 6 deletions

diff --git a/netsniff-ng.8 b/netsniff-ng.8
index 82c0f78..31c4907 100644
--- a/netsniff-ng.8
+++ b/netsniff-ng.8
@@ -77,12 +77,14 @@ a folder, a trafgen(8) configuration file or stdout (\[lq]-\[rq]). In the case o
 file that should not have the default pcap type (0xa1b2c3d4), the additional
 option \[lq]\-T\[rq] must be provided. If a directory is given, then, instead of a
 single pcap file, multiple pcap files are generated with rotation based on
-maximum file size or a given interval (\[lq]\-F\[rq] option). A trafgen configuration
-file can currently only be specified if the input device is a pcap file. To
-specify a  pcap file as the output device, the file name must have
-\[lq].pcap\[rq] as its extension. If stdout is given as a device, then a trafgen
-configuration will be written to stdout if the input device is a pcap file, or a
-pcap file if the input device is a networking device.
+maximum file size or a given interval (\[lq]\-F\[rq] option). Optionally,
+sending the SIGHUP signal to the netsniff-ng process causes a premature rotation
+of the file. A trafgen configuration file can currently only be specified if the
+input device is a pcap file. To specify a  pcap file as the output device, the
+file name must have \[lq].pcap\[rq] as its extension. If stdout is given as a
+device, then a trafgen configuration will be written to stdout if the input
+device is a pcap file, or a pcap file if the input device is a networking
+device.
 .PP
 .SS -C <id>, --fanout-group <id>
 If multiple netsniff-ng instances are being started that all have the same packet