IPアドレス文字列のチェック

2020 Apr. 12.
2020 Apr. 11.

自分なりに作ってみた。

単体コード

#!/bin/bash

# check IPv4 address string is correct


Command=`basename $0` 

# usage
function usage() {
cat << EOP
usage: ${Command} IPv4-address
EOP
}

if [ $# -ne 1 ]
then
  echo "Failed."
  usage
  exit 1
fi

# get VPN Gate server address 
IP=$1

## check IP
# count dots
NumDot=`echo -n $IP | sed -e 's@[^.]@@g' | wc -c`
if [ ${NumDot} -ne 3 ]; then
  echo "Number of dot in IP-address is not 3."
  exit 1
fi

# check number and digit of number
TmpIP=${IP}
LengthTmpIP=${#TmpIP}
while [ ${LengthTmpIP} -gt 0 ]
do
  # get top strings before 1st dot
  StrIPpart=`echo ${TmpIP} | grep -oP '^[0-9]*'`
  if [ ${#StrIPpart} -lt 1 ]
  then
    echo "No number in some area in IP-address."
    exit 1
  fi

  # store IPtmp for next loop
  TmpIP=`echo ${TmpIP} | sed -e "s/^${StrIPpart}//"`

  # if head of TmpIP is ".", remove "."
  HeadLetter=`echo ${TmpIP:0:1}`
  if [[ $HeadLetter = "." ]]
  then
    TmpIP=${TmpIP#.}

    # if TmpIP has no letter, then finish loop
    if [ ${#TmpIP} -lt 1 ]
    then
      break
    fi
  fi

  # check StrIPpart is number
  expr $StrIPpart + 1 >/dev/null 2>&1
  if [ $? -gt 1 ]
  then
    echo "Non-number-letters are included in IP-address."
    exit 1
  fi

  # check StarIPpart is 0-255
  if [[ $StrIPpart -lt 0 || $StrIPpart -gt 255 ]]
  then
    echo "Number of IP-address is out of range[0-255]."
    exit 1
  fi
  LengthTmpIP=${#TmpIP}
done

exit 0

プログラム中で関数として利用

function checkIPstr() {
  local IP=$1
  local NumDot=`echo -n $IP | sed -e 's@[^.]@@g' | wc -c`
  local TmpIP=${IP}
  local LengthTmpIP=${#TmpIP}
  local StrIPpart=""
  local HeadLetter=""

  ## check IP
  # count dots
  if [ ${NumDot} -ne 3 ]; then
    echo "Number of dot in IP-address is not 3."
    return 1
  fi

  if [ $LengthTmpIP -lt 8 ]
  then
    echo "Too few address-letters."
    return 1
  fi

  # check number and digit of number
  while [ ${LengthTmpIP} -gt 0 ]
  do
    # get top strings before 1st dot
    StrIPpart=`echo ${TmpIP} | grep -oP '^[0-9]*'`
    if [ ${#StrIPpart} -lt 1 ]
    then
      echo "No number in some area in IP-address."
      return 1
    fi

    # store IPtmp for next loop
    TmpIP=`echo ${TmpIP} | sed -e "s/^${StrIPpart}//"`

    # if head of TmpIP is ".", remove "."
    HeadLetter=`echo ${TmpIP:0:1}`
    if [[ $HeadLetter = "." ]]
    then
      TmpIP=${TmpIP#.}

      # if TmpIP has no letter, then finish loop
      if [ ${#TmpIP} -lt 1 ]
      then
        break
      fi
    fi

    # check StrIPpart is number
    expr $StrIPpart + 1 >/dev/null 2>&1
    if [ $? -gt 1 ]
    then
      echo "Non-number-letters are included in IP-address."
      return 1
    fi

    # check StarIPpart is 0-255
    if [[ $StrIPpart -lt 0 || $StrIPpart -gt 255 ]]
    then
      echo "Number of IP-address is out of range[0-255]."
      return 1
    fi
    LengthTmpIP=${#TmpIP}
  done

  return 0
}


##############
#### main ####
##############

# get IP-address 
IP=$1

## check IP-address-string
RetCheckIPstr=`checkIPstr $IP`
if [ $? -gt 0 ]
then
  echo $RetCheckIPstr
  exit 1
fi
exit 0