【Linux】ドル円為替情報をwgetコマンドで取得する

はじめに

ドル円レートをスクリプトベースで取得したい、と思った際にネットを見ていると
ISホールディングの外為オンラインが提供する下記のリンク先がありました。

このトップページから/rateaj/getrateと潜ったページをブラウザで見ると以下のように表示されます。

{"quotes":[{"high":"1.9448","open":"1.9380","bid":"1.9416","currencyPairCode":"GBPNZD","ask":"1.9433","low":"1.9378"},{"high":"80.61","open":"80.58","bid":"80.34","currencyPairCode":"CADJPY","ask":"80.39","low":"80.18"},
...

本記事ではこれらをLinux機からコマンドベースで取得するワンライナーを紹介します。

コマンド実行環境

$ cat /etc/os-release
PRETTY_NAME="Debian GNU/Linux 9 (stretch)"

為替情報の取得ワンライナー

（下記コマンドの実行頻度等、不正アクセスと疑われないようご注意ください）

$ wget -O - -U "" http://www.gaitameonline.com/rateaj/getrate 2> /dev/null

上記で取得でき、実際の実行結果は以下です。

{"quotes":[{"high":"1.9448","open":"1.9380","bid":"1.9421","currencyPairCode":"GBPNZD","ask":"1.9438","low":"1.9378"},{"high":"80.61","open":"80.58","bid":"80.48","currencyPairCode":"CADJPY","ask":"80.53","low":"80.18"},{"high":"1.8193","open":"1.8137","bid":"1.8163","currencyPairCode":"GBPAUD","ask":"1.8172","low":"1.8136"},{"high":"72.28","open":"72.24","bid":"72.14","currencyPairCode":"AUDJPY","ask":"72.17","low":"71.82"},{"high":"1.0693","open":"1.0681","bid":"1.0688","currencyPairCode":"AUDNZD","ask":"1.0698","low":"1.0673"},{"high":"1.4658","open":"1.4623","bid":"1.4639","currencyPairCode":"EURCAD","ask":"1.4646","low":"1.4615"},{"high":"1.0989","open":"1.0969","bid":"1.0983","currencyPairCode":"EURUSD","ask":"1.0984","low":"1.0968"},{"high":"67.61","open":"67.58","bid":"67.44","currencyPairCode":"NZDJPY","ask":"67.50","low":"67.18"},{"high":"1.3343","open":"1.3328","bid":"1.3329","currencyPairCode":"USDCAD","ask":"1.3335","low":"1.3324"},{"high":"0.8995","open":"0.8984","bid":"0.8991","currencyPairCode":"EURGBP","ask":"0.8995","low":"0.8973"},{"high":"1.2215","open":"1.2201","bid":"1.2212","currencyPairCode":"GBPUSD","ask":"1.2215","low":"1.2199"},{"high":"7.009","open":"7.008","bid":"6.986","currencyPairCode":"ZARJPY","ask":"7.136","low":"6.950"},{"high":"1.0925","open":"1.0924","bid":"1.0910","currencyPairCode":"EURCHF","ask":"1.0915","low":"1.0897"},{"high":"108.02","open":"107.89","bid":"108.00","currencyPairCode":"CHFJPY","ask":"108.05","low":"107.71"},{"high":"0.6725","open":"0.6721","bid":"0.6721","currencyPairCode":"AUDUSD","ask":"0.6723","low":"0.6709"},{"high":"0.9957","open":"0.9957","bid":"0.9933","currencyPairCode":"USDCHF","ask":"0.9937","low":"0.9920"},{"high":"117.96","open":"117.89","bid":"117.88","currencyPairCode":"EURJPY","ask":"117.90","low":"117.56"},{"high":"1.2155","open":"1.2149","bid":"1.2130","currencyPairCode":"GBPCHF","ask":"1.2139","low":"1.2114"},{"high":"1.7491","open":"1.7427","bid":"1.7465","currencyPairCode":"EURNZD","ask":"1.7477","low":"1.7422"},{"high":"0.6291","open":"0.6289","bid":"0.6283","currencyPairCode":"NZDUSD","ask":"0.6289","low":"0.6274"},{"high":"107.49","open":"107.47","bid":"107.33","currencyPairCode":"USDJPY","ask":"107.34","low":"107.03"},{"high":"1.6366","open":"1.6307","bid":"1.6334","currencyPairCode":"EURAUD","ask":"1.6342","low":"1.6304"},{"high":"0.6694","open":"0.6694","bid":"0.6676","currencyPairCode":"AUDCHF","ask":"0.6682","low":"0.6657"},{"high":"131.27","open":"131.15","bid":"131.07","currencyPairCode":"GBPJPY","ask":"131.10","low":"130.71"}]}

以下、補足です。

結果の読み方

それぞれのラベルと意味の対応は以下です。

high	高値
open	始値
bid	売り気配値
currencyPairCode	為替コード
ask	買い気配値
low	安値

関係式としては一般的に
high > bid > ask > low が成り立ちます。

ちなみに米ドル⇔日本円のcurrencyPairCodeは「USDJPY」です。

スクリプトの解説

単純に以下で実行すると

$ wget -O - http://www.gaitameonline.com/rateaj/getrate 2> /dev/null

以下のエラーとなります。

<html>
<head><title>Request Rejected</title></head>
<body>セキュリティの制限によりご利用できません。<br>
以下の内容をお試しの上、ご利用できない場合は、
...
・プロキシサーバを利用している場合は設定解除<br>
・PCを再起動<br>
・ルータを再起動<br><br>
Restriction of security can't use it.<br>
When you're trying the following contents and I can't use it.<br>
You cut down support ID and please make a contact to our man to contact.<br><br>
...
・ When using a proxy server, setting is released.<br>
・ A PC is restarted.<br>
・ A router is restarted.<br>

ただこれは過去に心当たりがあります。

要はボットのような利用を禁止してか、ユーザエージェントを入れないとエラーになる模様です。
よって上記コマンドでアクセスを行う場合も節度ある利用が求められます。