diff options
Diffstat (limited to 'manual/locale.texi')
| -rw-r--r-- | manual/locale.texi | 146 |
1 files changed, 114 insertions, 32 deletions
diff --git a/manual/locale.texi b/manual/locale.texi index 8bfd653edb..ee1c3a1201 100644 --- a/manual/locale.texi +++ b/manual/locale.texi @@ -29,6 +29,7 @@ will follow the conventions preferred by the user. * Setting the Locale:: How a program specifies the locale with library functions. * Standard Locales:: Locale names available on all systems. +* Locale Names:: Format of system-specific locale names. * Locale Information:: How to access the information for the locale. * Formatting Numbers:: A dedicated function to format numbers. * Yes-or-No Questions:: Check a Response against the locale. @@ -99,14 +100,16 @@ locale named @samp{espana-castellano} to use the standard conventions of most of Spain. The set of locales supported depends on the operating system you are -using, and so do their names. We can't make any promises about what -locales will exist, except for one standard locale called @samp{C} or -@samp{POSIX}. Later we will describe how to construct locales. -@comment (@pxref{Building Locale Files}). +using, and so do their names, except that the standard locale called +@samp{C} or @samp{POSIX} always exist. @xref{Locale Names}. + +In order to force the system to always use the default locale, the +user can set the @code{LC_ALL} environment variable to @samp{C}. @cindex combining locales -A user also has the option of specifying different locales for different -purposes---in effect, choosing a mixture of multiple locales. +A user also has the option of specifying different locales for +different purposes---in effect, choosing a mixture of multiple +locales. @xref{Locale Categories}. For example, the user might specify the locale @samp{espana-castellano} for most purposes, but specify the locale @samp{usa-english} for @@ -120,7 +123,7 @@ which locales apply. However, the user can choose to use each locale for a particular subset of those purposes. @node Locale Categories, Setting the Locale, Choosing Locale, Locales -@section Categories of Activities that Locales Affect +@section Locale Categories @cindex categories for locales @cindex locale categories @@ -128,7 +131,11 @@ The purposes that locales serve are grouped into @dfn{categories}, so that a user or a program can choose the locale for each category independently. Here is a table of categories; each name is both an environment variable that a user can set, and a macro name that you can -use as an argument to @code{setlocale}. +use as the first argument to @code{setlocale}. + +The contents of the environment variable (or the string in the second +argument to @code{setlocale}) has to be a valid locale name. +@xref{Locale Names}. @vtable @code @comment locale.h @@ -172,7 +179,7 @@ for affirmative and negative responses. @comment locale.h @comment ISO @item LC_ALL -This is not an environment variable; it is only a macro that you can use +This is not a category; it is only a macro that you can use with @code{setlocale} to set a single locale for all purposes. Setting this environment variable overwrites all selections by the other @code{LC_*} variables or @code{LANG}. @@ -355,13 +362,7 @@ The symbols in this section are defined in the header file @file{locale.h}. @c strndup @ascuheap @acsmem @c strcasecmp_l ok (C locale) The function @code{setlocale} sets the current locale for category -@var{category} to @var{locale}. A list of all the locales the system -provides can be created by running - -@pindex locale -@smallexample - locale -a -@end smallexample +@var{category} to @var{locale}. If @var{category} is @code{LC_ALL}, this specifies the locale for all purposes. The other possible values of @var{category} specify an @@ -386,10 +387,9 @@ is passed in as @var{locale} parameter. When you read the current locale for category @code{LC_ALL}, the value encodes the entire combination of selected locales for all categories. -In this case, the value is not just a single locale name. In fact, we -don't make any promises about what it looks like. But if you specify -the same ``locale name'' with @code{LC_ALL} in a subsequent call to -@code{setlocale}, it restores the same combination of locale selections. +If you specify the same ``locale name'' with @code{LC_ALL} in a +subsequent call to @code{setlocale}, it restores the same combination +of locale selections. To be sure you can use the returned string encoding the currently selected locale at a later time, you must make a copy of the string. It is not @@ -405,20 +405,15 @@ for @var{category}. If a nonempty string is given for @var{locale}, then the locale of that name is used if possible. +The effective locale name (either the second argument to +@code{setlocale}, or if the argument is an empty string, the name +obtained from the process environment) must be valid locale name. +@xref{Locale Names}. + If you specify an invalid locale name, @code{setlocale} returns a null pointer and leaves the current locale unchanged. @end deftypefun -The path used for finding locale data can be set using the -@code{LOCPATH} environment variable. The default path for finding -locale data is system specific. It is computed from the value given -as the prefix while configuring the C library. This value normally is -@file{/usr} or @file{/}. For the former the complete path is: - -@smallexample -/usr/lib/locale -@end smallexample - Here is an example showing how you might use @code{setlocale} to temporarily switch to a new locale. @@ -458,7 +453,7 @@ locale categories, and future versions of the library will do so. For portability, assume that any symbol beginning with @samp{LC_} might be defined in @file{locale.h}. -@node Standard Locales, Locale Information, Setting the Locale, Locales +@node Standard Locales, Locale Names, Setting the Locale, Locales @section Standard Locales The only locale names you can count on finding on all operating systems @@ -492,7 +487,94 @@ with the environment, rather than trying to specify some non-standard locale explicitly by name. Remember, different machines might have different sets of locales installed. -@node Locale Information, Formatting Numbers, Standard Locales, Locales +@node Locale Names, Locale Information, Standard Locales, Locales +@section Locale Names + +The following command prints a list of locales supported by the +system: + +@pindex locale +@smallexample + locale -a +@end smallexample + +@strong{Portability Note:} With the notable exception of the standard +locale names @samp{C} and @samp{POSIX}, locale names are +system-specific. + +Most locale names follow XPG syntax and consist of up to four parts: + +@smallexample +@var{language}[_@var{territory}[.@var{codeset}]][@@@var{modifier}] +@end smallexample + +Beside the first part, all of them are allowed to be missing. If the +full specified locale is not found, less specific ones are looked for. +The various parts will be stripped off, in the following order: + +@enumerate +@item +codeset +@item +normalized codeset +@item +territory +@item +modifier +@end enumerate + +For example, the locale name @samp{de_AT.iso885915@@euro} denotes a +German-language locale for use in Austria, using the ISO-8859-15 +(Latin-9) character set, and with the Euro as the currency symbol. + +In addition to locale names which follow XPG syntax, systems may +provide aliases such as @samp{german}. Both categories of names must +not contain the slash character @samp{/}. + +If the locale name starts with a slash @samp{/}, it is treated as a +path relative to the configured locale directories; see @code{LOCPATH} +below. The specified path must not contain a component @samp{..}, or +the name is invalid, and @code{setlocale} will fail. + +@strong{Portability Note:} POSIX suggests that if a locale name starts +with a slash @samp{/}, it is resolved as an absolute path. However, +@theglibc{} treats it as a relative path under the directories listed +in @code{LOCPATH} (or the default locale directory if @code{LOCPATH} +is unset). + +Locale names which are longer than an implementation-defined limit are +invalid and cause @code{setlocale} to fail. + +As a special case, locale names used with @code{LC_ALL} can combine +several locales, reflecting different locale settings for different +categories. For example, you might want to use a U.S. locale with ISO +A4 paper format, so you set @code{LANG} to @samp{en_US.UTF-8}, and +@code{LC_PAPER} to @samp{de_DE.UTF-8}. In this case, the +@code{LC_ALL}-style combined locale name is + +@smallexample +LC_CTYPE=en_US.UTF-8;LC_TIME=en_US.UTF-8;LC_PAPER=de_DE.UTF-8;@dots{} +@end smallexample + +followed by other category settings not shown here. + +@vindex LOCPATH +The path used for finding locale data can be set using the +@code{LOCPATH} environment variable. This variable lists the +directories in which to search for locale definitions, separated by a +colon @samp{:}. + +The default path for finding locale data is system specific. A typical +value for the @code{LOCPATH} default is: + +@smallexample +/usr/share/locale +@end smallexample + +The value of @code{LOCPATH} is ignored by privileged programs for +security reasons, and only the default directory is used. + +@node Locale Information, Formatting Numbers, Locale Names, Locales @section Accessing Locale Information There are several ways to access locale information. The simplest |