Reset idle TCP connection using gdb to send shutdown()

tcp-reset-connection.sh

#! /bin/sh

# Reset TCP connections with gdb

PORT="$1"
HOST="$2"
[ "$1" ] || {
    echo "Usage: $0 local-port host-ip-address"
    echo "e.g. $0 192.168.0.55 80   # reset tcp connection from 192.168.0.55 to local port 80"
    exit 1;
}
REGEXMATCH=""
for R in "$@" ; do
    case "$R" in
        *.*) REGEXMATCH="$REGEXMATCH -e $R:" ;;
        *)   REGEXMATCH="$REGEXMATCH -e :$R" ;;
    esac
done

# users:(("tgtd",2338,40))          # older style ss output
# users:(("brave",pid=77829,fd=43)) # newer style ss output, tagged
ss -etpn |
	egrep $REGEXMATCH |
	sed '
            /users:/ {
            s/.*users:(("\([^"]*\)".*,pid=\([0-9]*\).*,fd=\([0-9]*\).*/\1\t\2\t\3/; 
            s/.*users:(("\([^"]*\)",\([0-9]*\),\([0-9]*\).*/\1\t\2\t\3/;
            p; }; d ' |
        {
            while read _NAME _PID _FD ; do
		    echo "gdb -p $_PID --batch -ex 'call (int)shutdown(${_FD}u, 2)'; # Shut down socket $_FD in PID $_PID \"$_NAME\""
                    HITS=$((HITS+1))
            done
            [ "$HITS" ] || {
                    echo 1>&2 "No connections to port/host $*"
            }
        }