iankelling.org Git - automated-distro-installer/blob - dnsmasq-end-lease

   1 #!/bin/bash
   2 # I, Ian Kelling, follow the GNU license recommendations at
   3 # https://www.gnu.org/licenses/license-recommendations.en.html. They
   4 # recommend that small programs, < 300 lines, be licensed under the
   5 # Apache License 2.0. This file contains or is part of one or more small
   6 # programs. If a small program grows beyond 300 lines, I plan to change
   7 # to a recommended GPL license.
   8
   9 # Copyright 2024 Ian Kelling
  10
  11 # Licensed under the Apache License, Version 2.0 (the "License");
  12 # you may not use this file except in compliance with the License.
  13 # You may obtain a copy of the License at
  14
  15 #     http://www.apache.org/licenses/LICENSE-2.0
  16
  17 # Unless required by applicable law or agreed to in writing, software
  18 # distributed under the License is distributed on an "AS IS" BASIS,
  19 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  20 # See the License for the specific language governing permissions and
  21 # limitations under the License.
  22
  23
  24 # usage: wrt-reip PATTERN
  25 # Removes pattern from dnsmasq leases file and restart dnsmasq.
  26 # PATTERN should generally be an ip or a mac.
  27
  28 pattern=$1
  29
  30 exit_code=0
  31
  32 m() {
  33     printf "%s\n" "$*";
  34     "$@"
  35 }
  36
  37 m /etc/init.d/dnsmasq stop
  38
  39 tmp=/tmp/dhcp.leases.iank
  40 sed "/$pattern/d" /tmp/dhcp.leases >$tmp
  41
  42 if (( $(wc -l /tmp/dhcp.leases | awk '{print $1}') - 1 == $(wc -l $tmp | awk '{print $1}') )); then
  43   echo "info: found one less line after removing $pattern. installing new leases file"
  44   cp /tmp/dhcp.leases /tmp/dhcp.leases.iank-backup
  45   cat $tmp >/tmp/dhcp.leases
  46   m rm -f $tmp
  47 else
  48   exit_code=1
  49   cat <<EOF
  50 error: unexpected line count in /tmp/dhcp.leases.iank"
  51 try diffing /tmp/dhcp.leases{,.iank}
  52 EOF
  53 fi
  54
  55 m /etc/init.d/dnsmasq start
  56
  57 m exit $exit_code