core/library/intl/scripts/currency/generate.php

<?php

/**
 * Generates the json files stored in resources/currency.
 *
 * The ISO currency list is used as a base, since it doesn't contain
 * deprecated currencies, unlike CLDR (v25 has 139 deprecated entries).
 */

set_time_limit(0);

// Downloaded from http://www.currency-iso.org/en/home/tables/table-a1.html
$isoCurrencies = '../c2.xml';
// Downloaded from http://unicode.org/Public/cldr/26/json-full.zip
$cldrCurrencies = '../json-full/main/en-US/currencies.json';
$currencyData = '../json-full/supplemental/currencyData.json';
if (!file_exists($isoCurrencies)) {
    die("The $isoCurrencies file was not found");
}
if (!file_exists($cldrCurrencies)) {
    die("The $cldrCurrencies file was not found");
}
if (!file_exists($currencyData)) {
    die("The $currencyData file was not found");
}
if (!function_exists('collator_create')) {
    // Reimplementing intl's collator would be a huge undertaking, so we
    // use it instead to presort the generated locale specific data.
    die('The intl extension was not found.');
}

// Locales listed without a "-" match all variants.
// Locales listed with a "-" match only those exact ones.
$ignoredLocales = array(
    // Interlingua is a made up language.
    'ia',
    // Valencian differs from its parent only by a single character (è/é).
    'ca-ES-VALENCIA',
    // Those locales are 90% untranslated.
    'aa', 'as', 'az-Cyrl', 'az-Cyrl-AZ', 'bem', 'dua', 'gv', 'haw', 'ig', 'ii',
    'kkj', 'kok', 'kw', 'lkt', 'mgo', 'nnh', 'nr', 'nso', 'om', 'os', 'pa-Arab',
    'pa-Arab-PK', 'qu', 'rw', 'sah', 'smn', 'ss', 'ssy', 'st', 'tg', 'tn', 'ts',
    'uz-Arab', 'uz-Arab-AF', 've', 'vo', 'xh', 'yi',
    // Special "grouping" locales.
    'root', 'en-US-POSIX', 'en-001', 'en-150', 'es-419',
);

// Assemble the base data.
$baseData = array();
$currencyData = json_decode(file_get_contents($currencyData), true);
$currencyData = $currencyData['supplemental']['currencyData']['fractions'];
$isoData = simplexml_load_file($isoCurrencies);
foreach ($isoData->CcyTbl->CcyNtry as $currency) {
    $attributes = (array) $currency->CcyNm->attributes();
    if (!empty($attributes) && !empty($attributes['@attributes']['IsFund'])) {
        // Ignore funds.
        continue;
    }
    $currency = (array) $currency;
    if (empty($currency['Ccy'])) {
        // Ignore placeholders like "Antarctica".
        continue;
    }
    if (substr($currency['CtryNm'], 0, 2) == 'ZZ' || in_array($currency['Ccy'], array('XUA', 'XSU', 'XDR'))) {
        // Ignore special currencies.
        continue;
    }

    $currencyCode = $currency['Ccy'];
    $baseData[$currencyCode] = array(
        'code' => $currencyCode,
        'numeric_code' => $currency['CcyNbr'],
    );
    // Take the fraction digits from CLDR, not ISO, because it reflects real
    // life usage more closely. If the digits aren't set, that means that the
    // default value (2) should be used.
    if (isset($currencyData[$currencyCode]['_digits'])) {
        $fractionDigits = $currencyData[$currencyCode]['_digits'];
        if ($fractionDigits != 2) {
            $baseData[$currencyCode]['fraction_digits'] = $fractionDigits;
        }
    }
}

// Write out base.json.
ksort($baseData);
$json = json_encode($baseData, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
file_put_contents('base.json', $json);

// Gather available locales.
$locales = array();
if ($handle = opendir('../json-full/main')) {
    while (false !== ($entry = readdir($handle))) {
        if (substr($entry, 0, 1) != '.') {
            $entryParts = explode('-', $entry);
            if (!in_array($entry, $ignoredLocales) && !in_array($entryParts[0], $ignoredLocales)) {
                $locales[] = $entry;
            }
        }
    }
    closedir($handle);
}

// Create the localizations.
$currencies = array();
foreach ($locales as $locale) {
    $data = json_decode(file_get_contents('../json-full/main/' . $locale . '/currencies.json'), true);
    $data = $data['main'][$locale]['numbers']['currencies'];
    foreach ($data as $currencyCode => $currency) {
        if (isset($baseData[$currencyCode])) {
            $currencies[$locale][$currencyCode] = array(
                'name' => $currency['displayName'],
                'symbol' => $currency['symbol'],
            );
        }
    }
}

// Identify localizations that are the same as the ones for the parent locale.
// For example, "fr-FR" if "fr" has the same data.
$duplicates = array();
foreach ($currencies as $locale => $localizedCurrencies) {
    if (strpos($locale, '-') !== FALSE) {
        $localeParts = explode('-', $locale);
        array_pop($localeParts);
        $parentLocale = implode('-', $localeParts);
        $diff = array_udiff($localizedCurrencies, $currencies[$parentLocale], function ($first, $second) {
            return ($first['name'] == $second['name']) ? 0 : 1;
        });

        if (empty($diff)) {
            // The duplicates are not removed right away because they might
            // still be needed for other duplicate checks (for example,
            // when there are locales like bs-Latn-BA, bs-Latn, bs).
            $duplicates[] = $locale;
        }
    }
}
// Remove the duplicates.
foreach ($duplicates as $locale) {
    unset($currencies[$locale]);
}

// Write out the localizations.
foreach ($currencies as $locale => $localizedCurrencies) {
    $collator = collator_create($locale);
    uasort($localizedCurrencies, function($a, $b) use ($collator) {
        return collator_compare($collator, $a['name'], $b['name']);
    });

    $json = json_encode($localizedCurrencies, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
    file_put_contents($locale . '.json', $json);
}