Read EventLog(Win)/Syslog(*nix) in One Command

# 謎のコマンド ostype は uname を使ってなんとかすべし。
# Windows 環境下での uname の戻り値は環境差がきっと大きいです。
# あと、PS1_GET_EVENTLOG_OPT も需要に応じて適当に変更するとよし。
# Windows で nkf を使っている部分も環境に応じて調整するよろし！！
SYSLOG=/var/log/messages

# get application log output (*nix => syslog, windows => event log)
#   -f <logfile>    specify log file name (*nix only)
#   -n <count>      output the latest <count> lines
#   -m <word>       output the lines which contains the specified (alphanumeric) word in message
# more filters can be applied by external command such as grep, cut, etc.
#
# Requirements:
#   Windows: PowerShell 2.0 or later
getaplog()
{
  OPT_LOGPATH=$SYSLOG
  OPT_WORDINCL=""
  OPT_LINECOUNT=""
  OPT_ERROR=0

  OPTIND_OLD=$OPTIND
  OPTIND=1
  while getopts "f:m:n:" OPT; do
    case $OPT in
      f) OPT_LOGPATH="$OPTARG";;
      m) OPT_WORDINCL="$OPTARG";;
      n) OPT_LINECOUNT="$OPTARG";;
      ?) return 1;;
    esac
  done
  shift $(($OPTIND - 1))
  OPTIND=$OPTIND_OLD

  if [ `ostype` = "Windows" ]; then
    #PS1_GET_EVENTLOG_OPT="Application -Source XXX, YYY"
    PS1_GET_EVENTLOG_OPT="Application"
    if [ ! -z "$OPT_WORDINCL" ]; then
      PS1_GET_EVENTLOG_OPT="$PS1_GET_EVENTLOG_OPT -Message \"*$OPT_WORDINCL*\""
    fi
    if [ ! -z "$OPT_LINECOUNT" ]; then
      PS1_GET_EVENTLOG_OPT="$PS1_GET_EVENTLOG_OPT -Newest $OPT_LINECOUNT"
    fi

    yes "" | powershell -Command "\$OutputEncoding = [console]::OutputEncoding;" Get-EventLog $PS1_GET_EVENTLOG_OPT "| Sort-Object TimeGenerated | foreach { Write-Host (\$_.TimeGenerated.ToString('yyyy/MM/dd HH:mm:ss') + ' ' + \$_.MachineName + ' ' + \$_.Source + ': ' + \$_.Message) }" 2>/dev/null | nkf -s -w8
  else
    if [ ! -f "$OPT_LOGPATH" ]; then
      echo "getaplog: ${OPT_LOGPATH} file not exist" 2>&1
      return 1
    fi

    # lazy wildcard => regex conversion
    OPT_WORDINCL=`echo "$OPT_WORDINCL" | sed -e s/*/.*/g`

    if [ ! -z "$OPT_LINECOUNT" ]; then
      tail "-$OPT_LINECOUNT" $OPT_LOGPATH | grep "$OPT_WORDINCL"
    else
      grep "$OPT_WORDINCL" $OPT_LOGPATH
    fi
  fi
  return 0
}