Wikipediaから国旗を取得する ref: http://qiita.com/matyapiro31/items/ba062c7f7d545929fa28

file0.html

<img alt="シエラレオネの国旗" 
src="//upload.wikimedia.org/wikipedia/commons/thumb/
1/17/Flag_of_Sierra_Leone.svg/
125px-Flag_of_Sierra_Leone.svg.png"
...
>

file1.txt

echo "cat /html/body/div[3]/div[3]/div[4]/dl[1]/dd/table/tr[1]/th[1]/a/img/@src" \
|xmllint --shell $URL

getcountryflag

#!/bin/bash

function fix_name() {
  if [ ${1} = "アルメニア共和国" ];then
    echo アルメニア
  elif [ ${1} = "オランダ王国" ];then
      echo オランダ
  elif [ ${1} = "ギリシャ共和国" ];then
      echo ギリシャ
  elif [ ${1} = "ジョージア" ];then
      echo グルジア
  elif [ ${1} = "スロバキア共和国" ];then
      echo スロバキア
  elif [ ${1} = "デンマーク王国" ];then
      echo デンマーク
      elif [ ${1} = "シーランド" ];then
      echo シーランド公国
  fi
}

function get_flag() {
  country="${1}"
  if [ ! -z $(fix_name "${country}") ];then
    country=$(fix_name "${country}")
  fi
  if [ ${LANG:0:2} = "en" -o $LANG = 'C' ];then
    LNG="en"
    dir="/html/body/div[3]/div[3]/div[4]/table[1]/tr[2]/td/table/tr[1]/td[1]/a/img/@src"
  elif [ ${LANG:0:2} = "ja" ];then
    LNG="ja"
    dir="/html/body/div[3]/div[3]/div[4]/dl[1]/dd/table/tr[1]/th[1]/a/img/@src"
  elif [ ${LANG:0:2} = "zh" ];then
    LNG="zh"
    dir="/html/body/div[3]/div[3]/div[4]/table[1]/tr[3]/td/table/tr[1]/td[1]/a/img/@src"
  else
    echo "Your language is not supported." >&2
  fi
  wget -qO- https://${LNG}.wikipedia.org/wiki/"${country}" > /tmp/country.tmp
  array=(`echo "cat ${dir}"|xmllint --shell /tmp/country.tmp|tail -2|head -1|sed -e 's/\// /g'`)
 # rm /tmp/country.tmp

  log=$(LANG=C wget  https://upload.wikimedia.org/wikipedia/commons/${array[5]}/${array[6]}/${array[7]} 2>&1)
  fname=( $(echo "$log"|tail -1) )
  if [ "${fname[5]}" != "Found." ];then
    if [ ${2} != "true" ];then
      flag=$(echo "${fname[5]:1:-1}"|sed -e "s/\\\'/\'/g")
      gimp "${flag}" & >/dev/null
    else
      echo Done.
    fi
  else
    echo Faild to get flag of ${country}.
  fi
}

#option detection.
if [ ${#@} = 0 ];then
  echo "getcountryflag [COUNTRY] [OPTION]
  -i : interpret mode.
-d: download only.
-h: show this help."
  exit 0
fi
while getopts "idh" opts
do
  if [ ${opts} = "i" ];then
    std_in="true"
  elif [ ${opts} = "d" ];then
    download_only="true"
  elif [ ${opts} = "h" ];then
    echo "getcountryflag [COUNTRY] [OPTION]
    -i : interpret mode.
-d: download only.
-h: show this help."
    exit 0
  fi
done

while [ ${std_in:-false} != "true" -a -n "${1}" ]
do
  if [ ${1:0:1} != "-" ];then
    get_flag "${1}" ${download_only:-false}
  fi
  shift
done

while [ ${std_in:-false} = "true" ]
do
  printf '> '
  read -r country
  if [ "${country}" = "exit" -o "${country}" = "quit" ];then
    exit 0
  fi
  if [ -n "${country}" ];then
    get_flag "${country}" ${download_only:-false}
  fi
done