setlocale(3C) setlocale(3C)
NAME
setlocale(), getlocale() - set and get the locale of a program
SYNOPSIS
Obsolescent Interfaces
DESCRIPTION
The function sets, queries, or restores the aspect of a program's locale that is specified by the category argument. A program's locale
refers to those areas of the program's Native Language Support (NLS) environment for which the following values of category have been
defined:
Affects behavior of all categories below, as well as all
nl_langinfo(3C) items.
Affects behavior of regular expressions and the NLS
string collation functions (see string(3C), and regexp(5)).
Affects behavior of regular expressions, character classification,
and conversion functions (see ctype(3C), wctype(3C), wconv(3C), conv(3C), and regexp(5)). The category also
affects the behavior of all routines that process multibyte characters (see multibyte(3C)).
Affects the language in which messages are displayed and the
processing of affirmative and negative responses (see catopen(3C) and nl_langinfo(3C)).
Affects behavior of functions that handle monetary values (see
localeconv(3C) and strfmon(3C)).
Affects handling of the radix character in the formatted
input/output functions (see printf(3S), scanf(3S) and vprintf(3S)) and the string conversion functions (see
ecvt(3C) and strtod(3C)). also affects the numeric values found in the localeconv structure.
Affects the behavior of time conversion functions (see
getdate(3C), strftime(3C), and strptime(3C)).
All nl_langinfo(3C) items are affected by the setting of one of the categories listed above. See langinfo(5) to determine which categories
affect each item.
The value of the locale argument determines the action taken by locale is a pointer to a character string.
Note that while can be called concurrently from multiple threads, the locale data structures that get updated are not protected against
reads by other threads. Hence it is up to the application developer to ensure proper synchronization when changing locales.
Setting the Locale of a Program
To set the program's locale for category, accepts one of the following values as the locale argument: locale name, or (the empty string).
The actions prescribed by these values are as follows:
locale name If locale is a valid locale name (see lang(5)), sets that part of the NLS environment associated with category
as defined for that locale.
If the value of locale is set to sets that part of the NLS environment associated with category as defined for the locale (see
lang(5)). The locale is the default prior to successfully calling
Same as
If the value of locale is the empty string, the setting of that part of the NLS environment associated with category depends
upon the setting of the following environment variables in the user's environment (see environ(5)):
If category is any defined value other than sets that category as specified by the value of the environment.
This is also the case if is not set to the corresponding environment variable. If the environment variable is
not set or is set to the empty string, sets the category as specified by the value of the environment variable.
If is not set or is set to the empty string, then sets the category to the locale. For example,
sets the program's NLS environment associated with the category to the value specified by the user's environment
variable. All other aspects of the NLS environment are unaffected.
If category is then all categories are set corresponding to the value of if is set, or if is not set, except for
those categories in which the corresponding environment variable is set to a valid language name (see lang(5)).
In this case the value of the environment variable overrides the values of and for that category. If the values
of both and are not set or are set to the empty string, then the locale is used.
The following usage of results in the program's locale being set according to the user's language requirements:
Querying the Locale of a Program
queries the current NLS environment pertaining to category, if the value of locale is NULL. The query operation does not change the envi-
ronment. The purpose of performing a query is to save that aspect of the user's current NLS environment associated with category, in the
value returned by such that it can be restored with a subsequent call to
Restoring the Locale of a Program
To restore a category within the program locale, a call is made with the same category argument and the return string of the previous call
given as the locale argument.
returns a pointer to a structure (see The members of the structure contain information about the setting of each category. type determines
what information is contained in the structure. The only supported value of type is:
The structure member corresponding to each category contains a string
with the name of the locale currently set for that category. The string does not include modifier informa-
tion.
Obsolescent Interfaces
and set and get the locale of a program..
RETURN VALUE
If the pointer to a string is given for locale and the selection can be honored, the function returns a pointer to the string associated
with the specified category for the new locale. The maximum length of this string is bytes (see If the selection cannot be honored, the
function returns a null pointer and the program's locale is not changed.
A null pointer for locale causes to return a string associated with the category for the program's current locale.
The string returned by is such that a subsequent call with that string as the locale argument and its associated category restores that
part of the program's locale.
ERRORS
If a language name given through the locale argument does not identify a valid language name, or if the language name is more than 256
characters, or if the language is not available on the system (see lang(5)), then a null pointer is returned and the program's locale is
not changed. The same behavior occurs when the call:
is made and any category related environment variable in the user's environment identifies an invalid language name or a language that is
not available on the system.
If the category argument is not a defined category value, a null pointer is returned and the program's locale is not changed.
returns a string that reflects the current setting of that aspect of the NLS environment corresponding to the category argument. If this
return string is used in a subsequent call and the category arguments of the two calls do not match, the locale remains unchanged and a
null pointer is returned.
EXAMPLES
To set a program's entire locale based on the language requirements specified via the user's environment variables:
If in the example the user's environment variables were set as follows:
the and category items would be set to correspond to the language definition, the category items would be set to correspond to the language
definition for collation and the category items would be set corresponding to the language definition.
Using the same example, if the following call was made:
the contents of would be:
The next example shows the precedence of the environment variable:
with the following settings in the user's environment:
All categories will be loaded with
Another example showing the precedence of the environment variable:
with the following settings in the user's environment:
All categories will be loaded with
Another example with the environment variable:
with the following settings in the user's environment:
The category will be set to but all other categories will be set to
To set the date/time formats to
To set the collating sequence to the locale:
To set monetary handling to the value of the user's environment variable:
Note that if the environment variable is not set or is empty, the value of the user's environment variable is used.
To query a user's locale:
To restore the locale saved in the above example:
To query only the part of the user's locale pertaining to the category:
To restore the category of the user's locale saved in the above example:
WARNINGS
The format of the return string from is implementation specific, is not standardized across vendor's platforms, and is subject to change in
future releases. The return string is valid only for the life of the process invoking the and should only be used for restoring a previ-
ously stored locale setting within the same process.
Using as the locale argument is not recommended. An example of such incorrect usage is:
returns a character string which can be a language name, an empty string, or a null pointer; depending on the setting of the user's envi-
ronment variable. Each of these values as the locale argument define a specific action to be taken by Therefore the action taken by
depends upon the value returned from the call. To ensure that sets the program's locale based upon the setting of the user's environment
variables the following usage is recommended:
The value returned by points to an area that is overwritten during the next call to Be sure to copy these values to another area if they
are to be used after a subsequent call.
is an HP proprietary interface, which will be in a future release, and is not portable to other vendor's platforms.
The structure returned through a call to is overwritten during the next call to Be sure to save these values if they are to be used after a
subsequent call.
It should be noted that the locale state is common to all threads within a process.
and are obsolescent interfaces supported for compatibility with existing DCE applications. New multithreaded applications should use and
Any program that calls before with the oflag parameter set to may behave differently in this release than in previous releases because of
the addition of to In the past, was directed to the desired language by Now, with the oflag parameter set to is controlled by can modify
the category. For example, if the environment variables are set as follows:
and the following call to is made:
followed by a call to then will open the message catalogs for rather than
If you use and compile/link your application archive on PA-RISC systems, please note that has a dependency on that will require a change to
the compile/link command.
Compile:
Or compile with and
The option is positionally dependent and should occur at the beginning of the compile line. For optimum compatibility in future releases,
avoid using archive with other shared libraries except for as needed above.
AUTHOR
and were developed by OSF and HP.
FILES
SEE ALSO
locale(1), localedef(1M), conv(3C), ctype(3C), ecvt(3C), getdate(3C), multibyte(3C), nl_langinfo(3C), regcomp(3C), string(3C), perror(3C),
strfmon(3C), strftime(3C), string(3C), strptime(3C), strtod(3C), wcsftime(3C), wcstring(3C), printf(3S), scanf(3S), vprintf(3S), wconv(3C),
wctype(3C), wcstod(3C), wcstol(3C), environ(5), lang(5), langinfo(5), thread_safety(5).
STANDARDS CONFORMANCE
setlocale(3C)