Fellow monks,

We have run into a very strange issue with locales using comma as the decimal separator. Not sure where exactly the problem lies, but it seems that no matter if we say no locale; so we would be exempt from locale rules in a block — and this we need so numbers in JSON remain… well, numbers —, as long as we have an initialised Gtk2, we will get comma-separated floats.

~$ locale
< ... all set to hu_HU.UTF-8 ... >

[001] ~$ perl -e 'printf(q{%f}, 123.456);'
123.456000

[002] ~$ perl -e 'use locale; printf(q{%f}, 123.456);'
123.456000

[003] ~$ perl -e 'use locale; use POSIX; POSIX::setlocale("LC_ALL", "h
+u_HU.UTF-8"); printf q{%f}, 123.456;'
123.456000

[004] ~$ perl -e 'use Gtk2 -init; printf(q{%f}, 123.456);'
123,456000

[download]

I might not know my way around locale, but I thought the line in 003 would result in a comma... In any case, the moment Gtk2 enters the game, like in 004, it turns into a comma. Then we experimented further:

[005] ~$ perl -e 'use Gtk2 -init; print unpack("H*", 123.789) . "\n";'
3132332c373839

[006] ~$ perl -e 'use locale; print unpack("H*", 123.789) . "\n";' 
3132332e373839

[007] ~$ perl -e 'print unpack("H*", 123.789) . "\n";' 
3132332e373839

[008] ~$ perl -e 'use Gtk2 -init; print unpack("H*", "123.789") . "\n"
+;'
3132332e373839

[009] ~$ perl -e 'use Gtk2 -init; print unpack("H*", 123.789 . "") . "
+\n";'
3132332c373839

[download]

Notice how even unpack already only knows about the commaed string, once Gtk2 is in play — we haven’t found a way to stringify the number (in our real-world use case: the result of a time() command — without the locale mangling it.

So... any ideas? What are we doing wrong? Is there a way around this without forcing the locale to be C (or something “proper”) before Gtk2 gets initialised, ie. without actually breaking the entire locale thing?

In reply to Perl, Gtk2 and locale — a bit of a mess by Ralesk

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