shell编程测试文件权限

#!/bin/bash
#This script is used to test the file type.
#6/20/11
function usage()
{
  echo "Error:Must have a parameter."
  echo "Usage: "$0" filename"
  exit 1
}
function permission()
{
  if [ ! -e $1 ]
    then
      echo "Error:$1 file not find."
      return 1
  fi
  if [ -r $1 ]
    then
      PERMI="r"
  else
      PERMI="-"
  fi
  if [ -w $1 ]
    then
      PERMI=$PERMI"w"
  else
      PERMI=$PERMI"-"
  fi
  if [ -x $1 ]
    then
      PERMI=$PERMI"x"
  else
      PERMI=$PERMI"-"

  fi

  echo $PERMI

  return 0
}
if [ $# = 0 ]
  then
    usage
    exit 1
fi
if MESSAGE=`permission $1`
  then
   echo $1":"$MESSAGE
   exit 0
else
   echo $MESSAGE
   exit 1
fi