# RecordIface Linux BASH script
# Records network traffic on a network interface
# 
# Usage: RecordIface [TIMEPER] [OUTFILE] [APPEND] [GREPTEXT]
#
# [TIMEPER]  - Determines how often a capture occurs
# [OUTFILE]  - Specifies output filename where traaffic is stored
# [APPEND]   - Append to an existing file, or create a new file
# [GREPTEXT] - grep the output of netstat, filtering what is stored
#

if [ -z $1 ]; then
    echo
    echo Usage: RecordIface [TIMEPER] [OUTFILE] [APPEND] [GREPTEXT]
    echo
    echo No time period specified, defaulting to 600sec
    echo
    TIMEPER=600;
else
    TIMEPER=$1;
fi
if [ -z $2 ]; then
    echo No output file specified, defaulting to RecordIface.log
    echo
    OUTFILE=RecordIface.log
else
    OUTFILE=$2
fi
if [ -z $3 ]; then
    echo Append mode not specifiec, defaulting to APPEND=0
    echo
    APPEND=0
else
    APPEND=$3
fi
if [ -z $4 ]; then
    echo No regular expression specified, storing ALL output from netstat
    echo
    REGEXPR=.
else
    REGEXPR=$4
fi

echo TIMEPER=$TIMEPER
echo OUTFILE=$OUTFILE
echo APPEND=$APPEND
echo GREPTEXT=$REGEXPR
echo

while true; do
    echo -n .
    if [ $APPEND -eq 0 ]; then
        date > $OUTFILE
        netstat -i | grep $REGEXPR > $OUTFILE
    else
        date >> $OUTFILE
        netstat -i | grep $REGEXPR >> $OUTFILE
    fi
    sleep $TIMEPER;
done