setenv LC_ALL en_US.ISO8859-1
+or if you have the "env" application you can do in any shell
+
+ env LC_ALL=en_US.ISO8859-1 perl ...
+
If you do not know what shell you have, consult your local
helpdesk or the equivalent.
localeconv() takes no arguments, and returns B<a reference to> a hash.
The keys of this hash are variable names for formatting, such as
C<decimal_point> and C<thousands_sep>. The values are the
-corresponding, er, values. See L<POSIX (3)/localeconv> for a longer
+corresponding, er, values. See L<POSIX/localeconv> for a longer
example listing the categories an implementation might be expected to
provide; some provide more and others fewer. You don't need an
explicit C<use locale>, because localeconv() always observes the
}
print "\n";
+=head2 I18N::Langinfo
+
+Another interface for querying locale-dependent information is the
+I18N::Langinfo::langinfo() function, available at least in UNIX-like
+systems and VMS.
+
+The following example will import the langinfo() function itself and
+three constants to be used as arguments to langinfo(): a constant for
+the abbreviated first day of the week (the numbering starts from
+Sunday = 1) and two more constants for the affirmative and negative
+answers for a yes/no question in the current locale.
+
+ use I18N::Langinfo qw(langinfo ABDAY_1 YESSTR NOSTR);
+
+ my ($abday_1, $yesstr, $nostr) = map { langinfo } qw(ABDAY_1 YESSTR NOSTR);
+
+ print "$abday_1? [$yesstr/$nostr] ";
+
+In other words, in the "C" (or English) locale the above will probably
+print something like:
+
+ Sun? [yes/no]
+
+See L<I18N::Langinfo> for more information.
+
=head1 LOCALE CATEGORIES
The following subsections describe basic locale categories. Beyond these,
if you "use locale".
A B C D E a b c d e
- A a B b C c D d D e
+ A a B b C c D d E e
a A b B c C d D e E
a b c d e A B C D E
characters are in the current locale, in that locale's order:
use locale;
- print +(sort grep /\w/, map { chr() } 0..255), "\n";
+ print +(sort grep /\w/, map { chr } 0..255), "\n";
Compare this with the characters that you see and their order if you
state explicitly that the locale should be ignored:
no locale;
- print +(sort grep /\w/, map { chr() } 0..255), "\n";
+ print +(sort grep /\w/, map { chr } 0..255), "\n";
This machine-native collation (which is what you get unless S<C<use
locale>> has appeared earlier in the same block) must be used for
These functions aren't aware of such niceties as thousands separation and
so on. (See L<The localeconv function> if you care about these things.)
-Output produced by print() is B<never> affected by the
-current locale: it is independent of whether C<use locale> or C<no
-locale> is in effect, and corresponds to what you'd get from printf()
-in the "C" locale. The same is true for Perl's internal conversions
-between numeric and string formats:
+Output produced by print() is also affected by the current locale: it
+depends on whether C<use locale> or C<no locale> is in effect, and
+corresponds to what you'd get from printf() in the "C" locale. The
+same is true for Perl's internal conversions between numeric and
+string formats:
use POSIX qw(strtod);
use locale;
$n = 5/2; # Assign numeric 2.5 to $n
- $a = " $n"; # Locale-independent conversion to string
+ $a = " $n"; # Locale-dependent conversion to string
- print "half five is $n\n"; # Locale-independent output
+ print "half five is $n\n"; # Locale-dependent output
printf "half five is %g\n", $n; # Locale-dependent output
print "DECIMAL POINT IS COMMA\n"
if $n == (strtod("2,5"))[0]; # Locale-dependent conversion
+See also L<I18N::Langinfo> and C<RADIXCHAR>.
+
=head2 Category LC_MONETARY: Formatting of monetary amounts
The C standard defines the C<LC_MONETARY> category, but no function
does not quite meet your requirements: currency formatting is a hard nut
to crack.
+See also L<I18N::Langinfo> and C<CRNCYSTR>.
+
=head2 LC_TIME
Output produced by POSIX::strftime(), which builds a formatted
exists only to generate locale-dependent results, strftime() always
obeys the current C<LC_TIME> locale.
+See also L<I18N::Langinfo> and C<ABDAY_1>..C<ABDAY_7>, C<DAY_1>..C<DAY_7>,
+C<ABMON_1>..C<ABMON_12>, and C<ABMON_1>..C<ABMON_12>.
+
=head2 Other categories
The remaining locale category, C<LC_MESSAGES> (possibly supplemented
=item *
-Some systems are broken in that they allow the "C" locale to be
-overridden by users. If the decimal point character in the
-C<LC_NUMERIC> category of the "C" locale is surreptitiously changed
-from a dot to a comma, C<sprintf("%g", 0.123456e3)> produces a
-string result of "123,456". Many people would interpret this as
-one hundred and twenty-three thousand, four hundred and fifty-six.
-
-=item *
-
A sneaky C<LC_COLLATE> locale could result in the names of students with
"D" grades appearing ahead of those with "A"s.
=over 4
-=item B<Comparison operators> (C<lt>, C<le>, C<ge>, C<gt> and C<cmp>):
+=item *
+
+B<Comparison operators> (C<lt>, C<le>, C<ge>, C<gt> and C<cmp>):
Scalar true/false (or less/equal/greater) result is never tainted.
-=item B<Case-mapping interpolation> (with C<\l>, C<\L>, C<\u> or C<\U>)
+=item *
+
+B<Case-mapping interpolation> (with C<\l>, C<\L>, C<\u> or C<\U>)
Result string containing interpolated material is tainted if
C<use locale> is in effect.
-=item B<Matching operator> (C<m//>):
+=item *
+
+B<Matching operator> (C<m//>):
Scalar true/false result never tainted.
C<use locale> is in effect and the regular expression contains C<\w>,
C<\W>, C<\s>, or C<\S>.
-=item B<Substitution operator> (C<s///>):
+=item *
+
+B<Substitution operator> (C<s///>):
Has the same behavior as the match operator. Also, the left
operand of C<=~> becomes tainted when C<use locale> in effect
expression match involving C<\w>, C<\W>, C<\s>, or C<\S>; or of
case-mapping with C<\l>, C<\L>,C<\u> or C<\U>.
-=item B<Output formatting functions> (printf() and write()):
+=item *
+
+B<Output formatting functions> (printf() and write()):
+
+Results are never tainted because otherwise even output from print,
+for example C<print(1/7)>, should be tainted if C<use locale> is in
+effect.
-Success/failure result is never tainted.
+=item *
-=item B<Case-mapping functions> (lc(), lcfirst(), uc(), ucfirst()):
+B<Case-mapping functions> (lc(), lcfirst(), uc(), ucfirst()):
Results are tainted if C<use locale> is in effect.
-=item B<POSIX locale-dependent functions> (localeconv(), strcoll(),
+=item *
+
+B<POSIX locale-dependent functions> (localeconv(), strcoll(),
strftime(), strxfrm()):
Results are never tainted.
-=item B<POSIX character class tests> (isalnum(), isalpha(), isdigit(),
+=item *
+
+B<POSIX character class tests> (isalnum(), isalpha(), isdigit(),
isgraph(), islower(), isprint(), ispunct(), isspace(), isupper(),
isxdigit()):
into bankers, bikers, gamers, and so on. But, for now, it's the only
standard we've got. This may be construed as a bug.
+=head1 Unicode and UTF-8
+
+The support of Unicode is new starting from Perl version 5.6, and
+more fully implemented in the version 5.8. See L<perluniintro> and
+L<perlunicode> for more details.
+
+Usually locale settings and Unicode do not affect each other, but
+there are exceptions, see L<perlunicode/Locales> for examples.
+
=head1 BUGS
=head2 Broken systems
=head1 SEE ALSO
-L<POSIX (3)/isalnum>, L<POSIX (3)/isalpha>, L<POSIX (3)/isdigit>,
-L<POSIX (3)/isgraph>, L<POSIX (3)/islower>, L<POSIX (3)/isprint>,
-L<POSIX (3)/ispunct>, L<POSIX (3)/isspace>, L<POSIX (3)/isupper>,
-L<POSIX (3)/isxdigit>, L<POSIX (3)/localeconv>, L<POSIX (3)/setlocale>,
-L<POSIX (3)/strcoll>, L<POSIX (3)/strftime>, L<POSIX (3)/strtod>,
-L<POSIX (3)/strxfrm>.
+L<I18N::Langinfo>, L<perluniintro>, L<perlunicode>, L<open>,
+L<POSIX/isalnum>, L<POSIX/isalpha>,
+L<POSIX/isdigit>, L<POSIX/isgraph>, L<POSIX/islower>,
+L<POSIX/isprint>, L<POSIX/ispunct>, L<POSIX/isspace>,
+L<POSIX/isupper>, L<POSIX/isxdigit>, L<POSIX/localeconv>,
+L<POSIX/setlocale>, L<POSIX/strcoll>, L<POSIX/strftime>,
+L<POSIX/strtod>, L<POSIX/strxfrm>.
=head1 HISTORY