Is there a way to get the list of available locales in PHP?

Part of the confusion here is that PHP has two concepts called "locale" that are pretty much totally separate.

The first is the older one, which basically just uses the C locale features. That's what's behind setlocale and the locale support in some of PHP's functions (like money_format for example). This is what other answers that mention running locale -a on the command line and using setlocale are talking about.

PHP's Locale class and the other related functionality from the intl extension is newer, and doesn't work the same way. Instead of using the libc locale stuff, it uses a library called ICU, which ships its own locale data. PHP does provide a method to determine which locales are supported by this system: ResourceBundle::getLocales. The documentation is a little wooly here, but you can call this as a static method and pass the blank string to use ICU's default resources, thus getting a list of the supported locales for intl:

ResourceBundle::getLocales('');

I don't think there is a built in functions for this. You need to ask the operating system which locales are installed.

For example, if you run on a unix system you will need to execute the command:

$ locale -a

I also now solved this problem. Here's what happened.

<?phpreturn array(    'aa_DJ' => 'Afar (Djibouti)',    'aa_ER' => 'Afar (Eritrea)',    'aa_ET' => 'Afar (Ethiopia)',    'af_ZA' => 'Afrikaans (South Africa)',    'sq_AL' => 'Albanian (Albania)',    'sq_MK' => 'Albanian (Macedonia)',    'am_ET' => 'Amharic (Ethiopia)',    'ar_DZ' => 'Arabic (Algeria)',    'ar_BH' => 'Arabic (Bahrain)',    'ar_EG' => 'Arabic (Egypt)',    'ar_IN' => 'Arabic (India)',    'ar_IQ' => 'Arabic (Iraq)',    'ar_JO' => 'Arabic (Jordan)',    'ar_KW' => 'Arabic (Kuwait)',    'ar_LB' => 'Arabic (Lebanon)',    'ar_LY' => 'Arabic (Libya)',    'ar_MA' => 'Arabic (Morocco)',    'ar_OM' => 'Arabic (Oman)',    'ar_QA' => 'Arabic (Qatar)',    'ar_SA' => 'Arabic (Saudi Arabia)',    'ar_SD' => 'Arabic (Sudan)',    'ar_SY' => 'Arabic (Syria)',    'ar_TN' => 'Arabic (Tunisia)',    'ar_AE' => 'Arabic (United Arab Emirates)',    'ar_YE' => 'Arabic (Yemen)',    'an_ES' => 'Aragonese (Spain)',    'hy_AM' => 'Armenian (Armenia)',    'as_IN' => 'Assamese (India)',    'ast_ES' => 'Asturian (Spain)',    'az_AZ' => 'Azerbaijani (Azerbaijan)',    'az_TR' => 'Azerbaijani (Turkey)',    'eu_FR' => 'Basque (France)',    'eu_ES' => 'Basque (Spain)',    'be_BY' => 'Belarusian (Belarus)',    'bem_ZM' => 'Bemba (Zambia)',    'bn_BD' => 'Bengali (Bangladesh)',    'bn_IN' => 'Bengali (India)',    'ber_DZ' => 'Berber (Algeria)',    'ber_MA' => 'Berber (Morocco)',    'byn_ER' => 'Blin (Eritrea)',    'bs_BA' => 'Bosnian (Bosnia and Herzegovina)',    'br_FR' => 'Breton (France)',    'bg_BG' => 'Bulgarian (Bulgaria)',    'my_MM' => 'Burmese (Myanmar [Burma])',    'ca_AD' => 'Catalan (Andorra)',    'ca_FR' => 'Catalan (France)',    'ca_IT' => 'Catalan (Italy)',    'ca_ES' => 'Catalan (Spain)',    'zh_CN' => 'Chinese (China)',    'zh_HK' => 'Chinese (Hong Kong SAR China)',    'zh_SG' => 'Chinese (Singapore)',    'zh_TW' => 'Chinese (Taiwan)',    'cv_RU' => 'Chuvash (Russia)',    'kw_GB' => 'Cornish (United Kingdom)',    'crh_UA' => 'Crimean Turkish (Ukraine)',    'hr_HR' => 'Croatian (Croatia)',    'cs_CZ' => 'Czech (Czech Republic)',    'da_DK' => 'Danish (Denmark)',    'dv_MV' => 'Divehi (Maldives)',    'nl_AW' => 'Dutch (Aruba)',    'nl_BE' => 'Dutch (Belgium)',    'nl_NL' => 'Dutch (Netherlands)',    'dz_BT' => 'Dzongkha (Bhutan)',    'en_AG' => 'English (Antigua and Barbuda)',    'en_AU' => 'English (Australia)',    'en_BW' => 'English (Botswana)',    'en_CA' => 'English (Canada)',    'en_DK' => 'English (Denmark)',    'en_HK' => 'English (Hong Kong SAR China)',    'en_IN' => 'English (India)',    'en_IE' => 'English (Ireland)',    'en_NZ' => 'English (New Zealand)',    'en_NG' => 'English (Nigeria)',    'en_PH' => 'English (Philippines)',    'en_SG' => 'English (Singapore)',    'en_ZA' => 'English (South Africa)',    'en_GB' => 'English (United Kingdom)',    'en_US' => 'English (United States)',    'en_ZM' => 'English (Zambia)',    'en_ZW' => 'English (Zimbabwe)',    'eo' => 'Esperanto',    'et_EE' => 'Estonian (Estonia)',    'fo_FO' => 'Faroese (Faroe Islands)',    'fil_PH' => 'Filipino (Philippines)',    'fi_FI' => 'Finnish (Finland)',    'fr_BE' => 'French (Belgium)',    'fr_CA' => 'French (Canada)',    'fr_FR' => 'French (France)',    'fr_LU' => 'French (Luxembourg)',    'fr_CH' => 'French (Switzerland)',    'fur_IT' => 'Friulian (Italy)',    'ff_SN' => 'Fulah (Senegal)',    'gl_ES' => 'Galician (Spain)',    'lg_UG' => 'Ganda (Uganda)',    'gez_ER' => 'Geez (Eritrea)',    'gez_ET' => 'Geez (Ethiopia)',    'ka_GE' => 'Georgian (Georgia)',    'de_AT' => 'German (Austria)',    'de_BE' => 'German (Belgium)',    'de_DE' => 'German (Germany)',    'de_LI' => 'German (Liechtenstein)',    'de_LU' => 'German (Luxembourg)',    'de_CH' => 'German (Switzerland)',    'el_CY' => 'Greek (Cyprus)',    'el_GR' => 'Greek (Greece)',    'gu_IN' => 'Gujarati (India)',    'ht_HT' => 'Haitian (Haiti)',    'ha_NG' => 'Hausa (Nigeria)',    'iw_IL' => 'Hebrew (Israel)',    'he_IL' => 'Hebrew (Israel)',    'hi_IN' => 'Hindi (India)',    'hu_HU' => 'Hungarian (Hungary)',    'is_IS' => 'Icelandic (Iceland)',    'ig_NG' => 'Igbo (Nigeria)',    'id_ID' => 'Indonesian (Indonesia)',    'ia' => 'Interlingua',    'iu_CA' => 'Inuktitut (Canada)',    'ik_CA' => 'Inupiaq (Canada)',    'ga_IE' => 'Irish (Ireland)',    'it_IT' => 'Italian (Italy)',    'it_CH' => 'Italian (Switzerland)',    'ja_JP' => 'Japanese (Japan)',    'kl_GL' => 'Kalaallisut (Greenland)',    'kn_IN' => 'Kannada (India)',    'ks_IN' => 'Kashmiri (India)',    'csb_PL' => 'Kashubian (Poland)',    'kk_KZ' => 'Kazakh (Kazakhstan)',    'km_KH' => 'Khmer (Cambodia)',    'rw_RW' => 'Kinyarwanda (Rwanda)',    'ky_KG' => 'Kirghiz (Kyrgyzstan)',    'kok_IN' => 'Konkani (India)',    'ko_KR' => 'Korean (South Korea)',    'ku_TR' => 'Kurdish (Turkey)',    'lo_LA' => 'Lao (Laos)',    'lv_LV' => 'Latvian (Latvia)',    'li_BE' => 'Limburgish (Belgium)',    'li_NL' => 'Limburgish (Netherlands)',    'lt_LT' => 'Lithuanian (Lithuania)',    'nds_DE' => 'Low German (Germany)',    'nds_NL' => 'Low German (Netherlands)',    'mk_MK' => 'Macedonian (Macedonia)',    'mai_IN' => 'Maithili (India)',    'mg_MG' => 'Malagasy (Madagascar)',    'ms_MY' => 'Malay (Malaysia)',    'ml_IN' => 'Malayalam (India)',    'mt_MT' => 'Maltese (Malta)',    'gv_GB' => 'Manx (United Kingdom)',    'mi_NZ' => 'Maori (New Zealand)',    'mr_IN' => 'Marathi (India)',    'mn_MN' => 'Mongolian (Mongolia)',    'ne_NP' => 'Nepali (Nepal)',    'se_NO' => 'Northern Sami (Norway)',    'nso_ZA' => 'Northern Sotho (South Africa)',    'nb_NO' => 'Norwegian Bokmål (Norway)',    'nn_NO' => 'Norwegian Nynorsk (Norway)',    'oc_FR' => 'Occitan (France)',    'or_IN' => 'Oriya (India)',    'om_ET' => 'Oromo (Ethiopia)',    'om_KE' => 'Oromo (Kenya)',    'os_RU' => 'Ossetic (Russia)',    'pap_AN' => 'Papiamento (Netherlands Antilles)',    'ps_AF' => 'Pashto (Afghanistan)',    'fa_IR' => 'Persian (Iran)',    'pl_PL' => 'Polish (Poland)',    'pt_BR' => 'Portuguese (Brazil)',    'pt_PT' => 'Portuguese (Portugal)',    'pa_IN' => 'Punjabi (India)',    'pa_PK' => 'Punjabi (Pakistan)',    'ro_RO' => 'Romanian (Romania)',    'ru_RU' => 'Russian (Russia)',    'ru_UA' => 'Russian (Ukraine)',    'sa_IN' => 'Sanskrit (India)',    'sc_IT' => 'Sardinian (Italy)',    'gd_GB' => 'Scottish Gaelic (United Kingdom)',    'sr_ME' => 'Serbian (Montenegro)',    'sr_RS' => 'Serbian (Serbia)',    'sid_ET' => 'Sidamo (Ethiopia)',    'sd_IN' => 'Sindhi (India)',    'si_LK' => 'Sinhala (Sri Lanka)',    'sk_SK' => 'Slovak (Slovakia)',    'sl_SI' => 'Slovenian (Slovenia)',    'so_DJ' => 'Somali (Djibouti)',    'so_ET' => 'Somali (Ethiopia)',    'so_KE' => 'Somali (Kenya)',    'so_SO' => 'Somali (Somalia)',    'nr_ZA' => 'South Ndebele (South Africa)',    'st_ZA' => 'Southern Sotho (South Africa)',    'es_AR' => 'Spanish (Argentina)',    'es_BO' => 'Spanish (Bolivia)',    'es_CL' => 'Spanish (Chile)',    'es_CO' => 'Spanish (Colombia)',    'es_CR' => 'Spanish (Costa Rica)',    'es_DO' => 'Spanish (Dominican Republic)',    'es_EC' => 'Spanish (Ecuador)',    'es_SV' => 'Spanish (El Salvador)',    'es_GT' => 'Spanish (Guatemala)',    'es_HN' => 'Spanish (Honduras)',    'es_MX' => 'Spanish (Mexico)',    'es_NI' => 'Spanish (Nicaragua)',    'es_PA' => 'Spanish (Panama)',    'es_PY' => 'Spanish (Paraguay)',    'es_PE' => 'Spanish (Peru)',    'es_ES' => 'Spanish (Spain)',    'es_US' => 'Spanish (United States)',    'es_UY' => 'Spanish (Uruguay)',    'es_VE' => 'Spanish (Venezuela)',    'sw_KE' => 'Swahili (Kenya)',    'sw_TZ' => 'Swahili (Tanzania)',    'ss_ZA' => 'Swati (South Africa)',    'sv_FI' => 'Swedish (Finland)',    'sv_SE' => 'Swedish (Sweden)',    'tl_PH' => 'Tagalog (Philippines)',    'tg_TJ' => 'Tajik (Tajikistan)',    'ta_IN' => 'Tamil (India)',    'tt_RU' => 'Tatar (Russia)',    'te_IN' => 'Telugu (India)',    'th_TH' => 'Thai (Thailand)',    'bo_CN' => 'Tibetan (China)',    'bo_IN' => 'Tibetan (India)',    'tig_ER' => 'Tigre (Eritrea)',    'ti_ER' => 'Tigrinya (Eritrea)',    'ti_ET' => 'Tigrinya (Ethiopia)',    'ts_ZA' => 'Tsonga (South Africa)',    'tn_ZA' => 'Tswana (South Africa)',    'tr_CY' => 'Turkish (Cyprus)',    'tr_TR' => 'Turkish (Turkey)',    'tk_TM' => 'Turkmen (Turkmenistan)',    'ug_CN' => 'Uighur (China)',    'uk_UA' => 'Ukrainian (Ukraine)',    'hsb_DE' => 'Upper Sorbian (Germany)',    'ur_PK' => 'Urdu (Pakistan)',    'uz_UZ' => 'Uzbek (Uzbekistan)',    've_ZA' => 'Venda (South Africa)',    'vi_VN' => 'Vietnamese (Vietnam)',    'wa_BE' => 'Walloon (Belgium)',    'cy_GB' => 'Welsh (United Kingdom)',    'fy_DE' => 'Western Frisian (Germany)',    'fy_NL' => 'Western Frisian (Netherlands)',    'wo_SN' => 'Wolof (Senegal)',    'xh_ZA' => 'Xhosa (South Africa)',    'yi_US' => 'Yiddish (United States)',    'yo_NG' => 'Yoruba (Nigeria)',    'zu_ZA' => 'Zulu (South Africa)');