setlocale
setlocale provides the mechanism for controlling locale-specific features of the library. The category argument allows parts of the library to be localized as necessary without changing the entire locale-specific environment. Specifying the locale argument as a string gives an implementation maximum flexibility in providing a set of locales. For instance, an implementation could map the argument string into the name of a file containing appropriate localization parameters --- these files could then be added and modified without requiring any recompilation of a localizable program.
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