ztail

   1 #!/bin/bash
   2 # Usage : ztail [ -n 10 ] /var/log/foo
   3 #
   4 # Implements ztail -f /var/log/foo
   5 #
   6 # License: GPLv2
   7 # Author: Martin Langhoff <martin.langhoff@gmail.com>
   8 # Copyright: Remote Learner US - http://www.remote-learner.net/
   9 #
  10 mydir=$(dirname "${BASH_SOURCE[0]}")
  11
  12 taillines=10
  13
  14 while : ; do
  15         case "$1" in
  16                 -n)
  17                         taillines=$2
  18                         shift; shift ;;
  19                 *)
  20                         break ;;
  21         esac
  22 done
  23 logfile=$1
  24
  25 # flush before we get underway
  26 killall -s SIGUSR1 compresslog
  27
  28 ## setup trigger flush in a background loop
  29 (   sleep 1 # give time for the tailing to get started
  30         err=0
  31         while true ; do
  32                 killall -s SIGUSR1 compresslog 2>/dev/null
  33                 if [ $? -ne 0 ]; then
  34                         if [ $err -eq 0]; then
  35                                 echo "WARNING - ztail: compresslog is not running" >&2
  36                                 echo "WARNING - ztail:   or we are not root." >&2
  37                                 err=1
  38                         fi
  39                 fi
  40                 sleep 1
  41         done ) &
  42 FLUSHTRIGGERD=$!
  43 trap "kill $FLUSHTRIGGERD" SIGHUP SIGINT SIGTERM
  44
  45 $mydir/zcatfollow -n $taillines $logfile
  46
  47 kill $FLUSHTRIGGERD 2>/dev/null