#!/bin/sh

# TailMinus.sh
# 2008-07-21
# Chieh Cheng
# http://www.CynosureX.com/

# GNU General Public License (GPL) Version 2, June 1991

  scriptName=`echo $0 | sed s/\\\\/.*\\\\///g`

  perform ()
  {
    skipLines=$1
    file="$2"

    if [ -f "${file}" ]
    then
      lines=`cat "${file}" | wc -l`
      remain=`expr ${lines} - ${skipLines}`

      if [ ${remain} -gt 0 ]
      then
        tail -${remain} "${file}"
      fi
    else
      echo "${file} not found!"
    fi
  }

  usage ()
  {
    echo "  Usage:   ${scriptName} \"skip lines\" [ \"file\" ]"
    echo
    echo "           Specifying a file is optional."
    echo "           If file is not specified, then ${scriptName} reads"
    echo "           from the standard input."
  }

  if [ $# -gt 0 -a $# -lt 3 ]
  then
    skipLines=$1

    if [ $# -eq 2 ]
    then
      file="$2"
      perform ${skipLines} "${file}"
    else
      tmpFile=`GetTempPathName.ksh "${scriptName}"`
      while read line
      do
        echo "${line}" >> "${tmpFile}"
      done
      perform ${skipLines} "${tmpFile}"
      rm "${tmpFile}"
    fi
  else
    usage
  fi