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diff --git a/winsup/doc/setup-locale.xml b/winsup/doc/setup-locale.xml deleted file mode 100644 index de0532f62..000000000 --- a/winsup/doc/setup-locale.xml +++ /dev/null @@ -1,432 +0,0 @@ -<?xml version="1.0" encoding='UTF-8'?> -<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook V4.5//EN" - "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd"> - -<sect1 id="setup-locale"><title>Internationalization</title> - -<sect2 id="setup-locale-ov"><title>Overview</title> - -<para> -Internationalization support is controlled by the <envar>LANG</envar> and -<envar>LC_xxx</envar> environment variables. You can set all of them -but Cygwin itself only honors the variables <envar>LC_ALL</envar>, -<envar>LC_CTYPE</envar>, and <envar>LANG</envar>, in this order, according -to the POSIX standard. The content of these variables should follow the -POSIX standard for a locale specifier. The correct form of a locale -specifier is</para> - -<screen> - language[[_TERRITORY][.charset][@modifier]] -</screen> - -<para>"language" is a lowercase two character string per ISO 639-1, or, -if there is no ISO 639-1 code for the language (for instance, "Lower Sorbian"), -a three character string per ISO 639-3.</para> - -<para>"TERRITORY" is an uppercase two character string per ISO 3166, charset is -one of a list of supported character sets. The modifier doesn't matter -here (though some are recognized, see below). If you're interested in the -exact description, you can find it in the online publication of the POSIX -manual pages on the homepage of the -<ulink url="http://www.opengroup.org/">Open Group</ulink>.</para> - -<para>Typical locale specifiers are</para> - -<screen> - "de_CH" language = German, territory = Switzerland, default charset - "fr_FR.UTF-8" language = french, territory = France, charset = UTF-8 - "ko_KR.eucKR" language = korean, territory = South Korea, charset = eucKR - "syr_SY" language = Syriac, territory = Syria, default charset -</screen> - -<para> -If the locale specifier does not follow the above form, Cygwin checks -if the locale is one of the locale aliases defined in the file -<filename>/usr/share/locale/locale.alias</filename>. If so, and if -the replacement localename is supported by the underlying Windows, -the locale is accepted, too. So, given the default content of the -<filename>/usr/share/locale/locale.alias</filename> file, the below -examples would be valid locale specifiers as well. -</para> - -<screen> - "catalan" defined as "ca_ES.ISO-8859-1" in locale.alias - "japanese" defined as "ja_JP.eucJP" in locale.alias - "turkish" defined as "tr_TR.ISO-8859-9" in locale.alias -</screen> - -<para>The file <filename>/usr/share/locale/locale.alias</filename> is -provided by the gettext package under Cygwin.</para> - -<para> -At application startup, the application's locale is set to the default -"C" or "POSIX" locale. Under Cygwin 1.7.2 and later, this locale defaults -to the ASCII character set on the application level. If you want to stick -to the "C" locale and only change to another charset, you can define this -by setting one of the locale environment variables to "C.charset". For -instance</para> - -<screen> - "C.ISO-8859-1" -</screen> - -<note><para>The default locale in the absence of the aforementioned locale -environment variables is "C.UTF-8".</para></note> - -<para>Windows uses the UTF-16 charset exclusively to store the names -of any object used by the Operating System. This is especially important -with filenames. Cygwin uses the setting of the locale environment variables -<envar>LC_ALL</envar>, <envar>LC_CTYPE</envar>, and <envar>LANG</envar>, to -determine how to convert Windows filenames from their UTF-16 representation -to the singlebyte or multibyte character set used by Cygwin.</para> - -<para> -The setting of the locale environment variables at process startup -is effective for Cygwin's internal conversions to and from the Windows UTF-16 -object names for the entire lifetime of the current process. Changing -the environment variables to another value changes the way filenames are -converted in subsequently started child processes, but not within the same -process.</para> - -<para> -However, even if one of the locale environment variables is set to -some other value than "C", this does <emphasis>only</emphasis> affect -how Cygwin itself converts filenames. As the POSIX standard requires, -it's the application's responsibility to activate that locale for its -own purposes, typically by using the call</para> - -<screen> - setlocale (LC_ALL, ""); -</screen> - -<para>early in the application code. Again, so that this doesn't get -lost: If the application calls setlocale as above, and there is none -of the important locale variables set in the environment, the locale -is set to the default locale, which is "C.UTF-8".</para> - -<para>But what about applications which are not locale-aware? Per POSIX, -they are running in the "C" or "POSIX" locale, which implies the ASCII -charset. The Cygwin DLL itself, however, will nevertheless use the locale -set in the environment (or the "C.UTF-8" default locale) for converting -filenames etc.</para> - -<para>When the locale in the environment specifies an ASCII charset, -for example "C" or "en_US.ASCII", Cygwin will still use UTF-8 -under the hood to translate filenames. This allows for easier -interoperability with applications running in the default "C.UTF-8" locale. -</para> - -<para> -Starting with Cygwin 1.7.2, the language and territory are used to -fetch locale-dependent information from Windows. If the language and -territory are not known to Windows, the <function>setlocale</function> -function fails.</para> - -<para>The following modifiers are recognized. Any other modifier is simply -ignored for now.</para> - -<itemizedlist mark="bullet"> - -<listitem><para> -For locales which use the Euro (EUR) as currency, the modifier "@euro" -can be added to enforce usage of the ISO-8859-15 character set, which -includes a character for the "Euro" currency sign. -</para></listitem> - -<listitem><para> -The default script used for all Serbian language locales (sr_BA, sr_ME, sr_RS, -and the deprecated sr_CS and sr_SP) is cyrillic. With the "@latin" modifier -it gets switched to the latin script with the respective collation behaviour. -</para></listitem> - -<listitem><para> -The default charset of the "be_BY" locale (Belarusian/Belarus) is CP1251. -With the "@latin" modifier it's UTF-8. -</para></listitem> - -<listitem><para> -The default charset of the "tt_RU" locale (Tatar/Russia) is ISO-8859-5. -With the "@iqtelif" modifier it's UTF-8. -</para></listitem> - -<listitem><para> -The default charset of the "uz_UZ" locale (Uzbek/Uzbekistan) is ISO-8859-1. -With the "@cyrillic" modifier it's UTF-8. -</para></listitem> - -<listitem><para> -There's a class of characters in the Unicode character set, called the -"CJK Ambiguous Width" characters. For these characters, the width -returned by the wcwidth/wcswidth functions is usually 1. This can be a -problem with East-Asian languages, which historically use character sets -where these characters have a width of 2. Therefore, wcwidth/wcswidth -return 2 as the width of these characters when an East-Asian charset such -as GBK or SJIS is selected, or when UTF-8 is selected and the language is -specified as "zh" (Chinese), "ja" (Japanese), or "ko" (Korean). This is -not correct in all circumstances, hence the locale modifier "@cjknarrow" -can be used to force wcwidth/wcswidth to return 1 for the ambiguous width -characters. -</para></listitem> - -</itemizedlist> - -</sect2> - -<sect2 id="setup-locale-how"><title>How to set the locale</title> - -<itemizedlist mark="bullet"> - -<listitem><para> -Assume that you've set one of the aforementioned environment variables to some -valid POSIX locale value, other than "C" and "POSIX". Assume further that -you're living in Japan. You might want to use the language code "ja" and the -territory "JP", thus setting, say, <envar>LANG</envar> to "ja_JP". You didn't -set a character set, so what will Cygwin use now? Starting with Cygwin 1.7.2, -the default character set is determined by the default Windows ANSI codepage -for this language and territory. Cygwin uses a character set which is the -typical Unix-equivalent to the Windows ANSI codepage. For instance:</para> - -<screen> - "en_US" ISO-8859-1 - "el_GR" ISO-8859-7 - "pl_PL" ISO-8859-2 - "pl_PL@euro" ISO-8859-15 - "ja_JP" EUCJP - "ko_KR" EUCKR - "te_IN" UTF-8 -</screen> -</listitem> - -<listitem><para> -You don't want to use the default character set? In that case you have to -specify the charset explicitly. For instance, assume you're from Japan and -don't want to use the japanese default charset EUC-JP, but the Windows -default charset SJIS. What you can do, for instance, is to set the -<envar>LANG</envar> variable in the <command>mintty</command> Cygwin Terminal -in the "Text" section of its "Options" dialog. If you're starting your -Cygwin session via a batch file or a shortcut to a batch file, you can also -just set LANG there:</para> - -<screen> - @echo off - - C: - chdir C:\cygwin\bin - set LANG=ja_JP.SJIS - bash --login -i -</screen> - -<note><para>For a list of locales supported by your Windows machine, use the new -<command>locale -a</command> command, which is part of the Cygwin package. -For a description see <xref linkend="locale"></xref></para></note> - -<note><para>For a list of supported character sets, see -<xref linkend="setup-locale-charsetlist"></xref> -</para></note> -</listitem> - -<listitem><para> -Last, but not least, most singlebyte or doublebyte charsets have a big -disadvantage. Windows filesystems use the Unicode character set in the -UTF-16 encoding to store filename information. Not all characters -from the Unicode character set are available in a singlebyte or doublebyte -charset. While Cygwin has a workaround to access files with unusual -characters (see <xref linkend="pathnames-unusual"></xref>), a better -workaround is to use always the UTF-8 character set.</para> - -<para><emphasis>UTF-8 is the only multibyte character set which can represent -every Unicode character.</emphasis></para> - -<screen> - set LANG=es_MX.UTF-8 -</screen> - -<para>For a description of the Unicode standard, see the homepage of the -<ulink url="http://www.unicode.org/">Unicode Consortium</ulink>. -</para></listitem> - -</itemizedlist> - -</sect2> - -<sect2 id="setup-locale-console"><title>The Windows Console character set</title> - -<para>Sometimes the Windows console is used to run Cygwin applications. -While terminal emulations like the Cygwin Terminal <command>mintty</command> -or <command>xterm</command> have a distinct way to set the character set -used for in- and output, the Windows console hasn't such a way, since it's -not an application in its own right.</para> - -<para>This problem is solved in Cygwin as follows. When a Cygwin -process is started in a Windows console (either explicitly from cmd.exe, -or implicitly by, for instance, running the -<filename>C:\cygwin\Cygwin.bat</filename> batch file), the Console character -set is determined by the setting of the aforementioned -internationalization environment variables, the same way as described in -<xref linkend="setup-locale-how"></xref>. </para> - -<para>What is that good for? Why not switch the console character set with -the applications requirements? After all, the application knows if it uses -localization or not. However, what if a non-localized application calls -a remote application which itself is localized? This can happen with -<command>ssh</command> or <command>rlogin</command>. Both commands don't -have and don't need localization and they never call -<function>setlocale</function>. Setting one of the internationalization -environment variable to the same charset as the remote machine before -starting <command>ssh</command> or <command>rlogin</command> fixes that -problem.</para> - -</sect2> - -<sect2 id="setup-locale-problems"><title>Potential Problems when using Locales</title> - -<para> -You can set the above internationalization variables not only when -starting the first Cygwin process, but also in your Cygwin shell on the -fly, even switch to yet another character set, and yet another. In bash -for instance:</para> - -<screen> - <prompt>bash$</prompt> export LC_CTYPE="nl_BE.UTF-8" -</screen> - -<para>However, here's a problem. At the start of the first Cygwin process -in a session, the Windows environment is converted from UTF-16 to UTF-8. -The environment is another of the system objects stored in UTF-16 in -Windows.</para> - -<para>As long as the environment only contains ASCII characters, this is -no problem at all. But if it contains native characters, and you're planning -to use, say, GBK, the environment will result in invalid characters in -the GBK charset. This would be especially a problem in variables like -<envar>PATH</envar>. To circumvent the worst problems, Cygwin converts -the <envar>PATH</envar> environment variable to the charset set in the -environment, if it's different from the UTF-8 charset.</para> - -<note><para>Per POSIX, the name of an environment variable should only -consist of valid ASCII characters, and only of uppercase letters, digits, and -the underscore for maximum portability.</para></note> - -<para>Symbolic links, too, may pose a problem when switching charsets on -the fly. A symbolic link contains the filename of the target file the -symlink points to. When a symlink had been created with older versions -of Cygwin, the current ANSI or OEM character set had been used to store -the target filename, dependent on the old <envar>CYGWIN</envar> -environment variable setting <envar>codepage</envar> (see <xref -linkend="cygwinenv-removed-options"></xref>. If the target filename -contains non-ASCII characters and you use another character set than -your default ANSI/OEM charset, the target filename of the symlink is now -potentially an invalid character sequence in the new character set. -This behaviour is not different from the behaviour in other Operating -Systems. So, if you suddenly can't access a symlink anymore which -worked all these years before, maybe it's because you switched to -another character set. This doesn't occur with symlinks created with -Cygwin 1.7 or later. </para> - -<para>Another problem you might encounter is that older versions of -Windows did not install all charsets by default. If you are running -Windows XP or older, you can open the "Regional and Language Options" -portion of the Control Panel, select the "Advanced" tab, and select -entries from the "Code page conversion tables" list. The following -entries are useful to cygwin: 932/SJIS, 936/GBK, 949/EUC-KR, 950/Big5, -20932/EUC-JP.</para> - -</sect2> - -<sect2 id="setup-locale-charsetlist"><title>List of supported character sets</title> - -<para>Last but not least, here's the list of currently supported character -sets. The left-hand expression is the name of the charset, as you would use -it in the internationalization environment variables as outlined above. -Note that charset specifiers are case-insensitive. <literal>EUCJP</literal> -is equivalent to <literal>eucJP</literal> or <literal>eUcJp</literal>. -Writing the charset in the exact case as given in the list below is a -good convention, though. -</para> - -<para>The right-hand side is the number of the equivalent Windows -codepage as well as the Windows name of the codepage. They are only -noted here for reference. Don't try to use the bare codepage number or -the Windows name of the codepage as charset in locale specifiers, unless -they happen to be identical with the left-hand side. Especially in case -of the "CPxxx" style charsets, always use them with the trailing "CP".</para> - -<para>This works:</para> - -<screen> - set LC_ALL=en_US.CP437 -</screen> - -<para>This does <emphasis>not</emphasis> work:</para> - -<screen> - set LC_ALL=en_US.437 -</screen> - -<para>You can find a full list of Windows codepages on the Microsoft MSDN page -<ulink url="http://msdn.microsoft.com/en-us/library/dd317756(VS.85).aspx">Code Page Identifiers</ulink>.</para> - -<screen> - Charset Codepage - ------------------- ------------------------------------------- - ASCII 20127 (US_ASCII) - - CP437 437 (OEM United States) - CP720 720 (DOS Arabic) - CP737 737 (OEM Greek) - CP775 775 (OEM Baltic) - CP850 850 (OEM Latin 1, Western European) - CP852 852 (OEM Latin 2, Central European) - CP855 855 (OEM Cyrillic) - CP857 857 (OEM Turkish) - CP858 858 (OEM Latin 1 + Euro Symbol) - CP862 862 (OEM Hebrew) - CP866 866 (OEM Russian) - CP874 874 (ANSI/OEM Thai) - CP932 932 (Shift_JIS, not exactly identical to SJIS) - CP1125 1125 (OEM Ukraine) - CP1250 1250 (ANSI Central European) - CP1251 1251 (ANSI Cyrillic) - CP1252 1252 (ANSI Latin 1, Western European) - CP1253 1253 (ANSI Greek) - CP1254 1254 (ANSI Turkish) - CP1255 1255 (ANSI Hebrew) - CP1256 1256 (ANSI Arabic) - CP1257 1257 (ANSI Baltic) - CP1258 1258 (ANSI/OEM Vietnamese) - - ISO-8859-1 28591 (ISO-8859-1) - ISO-8859-2 28592 (ISO-8859-2) - ISO-8859-3 28593 (ISO-8859-3) - ISO-8859-4 28594 (ISO-8859-4) - ISO-8859-5 28595 (ISO-8859-5) - ISO-8859-6 28596 (ISO-8859-6) - ISO-8859-7 28597 (ISO-8859-7) - ISO-8859-8 28598 (ISO-8859-8) - ISO-8859-9 28599 (ISO-8859-9) - ISO-8859-10 - (not available) - ISO-8859-11 - (not available) - ISO-8859-13 28603 (ISO-8859-13) - ISO-8859-14 - (not available) - ISO-8859-15 28605 (ISO-8859-15) - ISO-8859-16 - (not available) - - Big5 950 (ANSI/OEM Traditional Chinese) - EUCCN or euc-CN 936 (ANSI/OEM Simplified Chinese) - EUCJP or euc-JP 20932 (EUC Japanese) - EUCKR or euc-KR 949 (EUC Korean) - GB2312 936 (ANSI/OEM Simplified Chinese) - GBK 936 (ANSI/OEM Simplified Chinese) - GEORGIAN-PS - (not available) - KOI8-R 20866 (KOI8-R Russian Cyrillic) - KOI8-U 21866 (KOI8-U Ukrainian Cyrillic) - PT154 - (not available) - SJIS - (not available, almost, but not exactly CP932) - TIS620 or TIS-620 874 (ANSI/OEM Thai) - - UTF-8 or utf8 65001 (UTF-8) -</screen> - -</sect2> - -</sect1> |