locale(3perl)           Perl Programmers Reference Guide           locale(3perl)

       locale - Perl pragma to use or avoid POSIX locales for built-in

       DO NOT USE this pragma in scripts that have multiple threads active.  The
       locale is not local to a single thread.  Another thread may change the
       locale at any time, which could cause at a minimum that a given thread is
       operating in a locale it isn't expecting to be in.  On some platforms,
       segfaults can also occur.  The locale change need not be explicit; some
       operations cause perl to change the locale itself.  You are vulnerable
       simply by having done a "use locale".

           @x = sort @y;      # Native-platform/Unicode code point sort order
               use locale;
               @x = sort @y;  # Locale-defined sort order
           @x = sort @y;      # Native-platform/Unicode code point sort order
                              # again

       This pragma tells the compiler to enable (or disable) the use of POSIX
       locales for built-in operations (for example, LC_CTYPE for regular
       expressions, LC_COLLATE for string comparison, and LC_NUMERIC for number
       formatting).  Each "use locale" or "no locale" affects statements to the
       end of the enclosing BLOCK.

       See perllocale for more detailed information on how Perl supports

       On systems that don't have locales, this pragma will cause your
       operations to behave as if in the "C" locale; attempts to change the
       locale will fail.

perl v5.34.0                       2021-07-18                      locale(3perl)