ttcn3-tcpdump-start.sh: Wait for tcpdump to start recording

We generate some fake transit and we wait until we catch tcpdump already
saved some packet into the pcap file, this way making sure it is already
recording before starting the test.

The -U flag (--packet-buffered) is added to increase the chances to
sleep less time waiting for stuff being saved into the pcap file.
According to tcpdump manual:
"""
If  the  -w option is specified, make the saved raw packet output ``packet-buffered''; i.e., as each packet is saved, it will
              be written to the output file, rather than being written only when the output buffer fills.
"""

Change-Id: I91cfd84ff5356857a13af1901abfe2204a93f76d

0 files changed, 0 insertions, 0 deletions