getopts使用样例

使用getopts命令读取unix格式选项
    UNIX格式选项指如下格式的命令行参数：
    command -options parameters
 
    使用格式：
    getopts option_string variable
 
    具体使用方法请参考getopts的在线文档(man getopts).
 
    示例如下：
 
         #newdate
         if [ $# -lt 1 ]
         then
             date
         else
            while getopts mdyDHMSTjJwahr OPTION
            do
               case $OPTION
               in
                  m) date '+%m ';;  # Month of Year
                  d) date '+%d ';;  # Day of Month
                  y) date '+%y ';;  # Year
                  D) date '+%D ';;  # MM/DD/YY
                  H) date '+%H ';;  # Hour
                  M) date '+%M ';;  # Minute
                  S) date '+%S ';;  # Second
                  T) date '+%T ';;  # HH:MM:SS
                  j) date '+%j ';;  # day of year
                  J) date '+%y%j ';;# 5 digit Julian date
                  w) date '+%w ';;  # Day of the Week
                  a) date '+%a ';;  # Day abbreviation
                  h) date '+%h ';;  # Month abbreviation
                  r) date '+%r ';;  # AM-PM time
                  \?) echo "Invalid option $OPTION";;
               esac
            done
         fi
 
         $ newdate -J
         94031
         $ newdate -a -h -d
         Mon
         Jan
         31
         $ newdate -ahd
         Mon
         Jan
         31
         $
 
 
         示例程序：复制程序
 
         # Syntax: duplicate [-c integer] [-v] filename
         #    where integer is the number of duplicate copies
         #    and -v is the verbose option
 
         COPIES=1
         VERBOSE=N
 
 
         while getopts vc: OPTION
         do
            case $OPTION
            in
               c) COPIES=$OPTARG;;
               v) VERBOSE=Y;;
               \?) echo "Illegal Option"
                   exit 1;;
            esac
         done
 
         if [ $OPTIND -gt $# ]
         then
            echo "No file name specified"
            exit 2
         fi
 
 
         shift `expr $OPTIND -1`
 
         FILE=
         COPY=0
 
         while [ $COPIES -gt $COPY ]
         do
            COPY=`expr $COPY + 1`
            cp $FILE $$
            if [ VERBOSE = Y ]
            then
               echo $$
            fi
         done
 
 
         $ duplicate -v fileA
         fileA1
         $ duplicate -c 3 -v fileB
         fileB1
         fileB2
         fileB3