Re^5: Character in 'b' format wrapped in unpack

When you do my $thing = chr( 12345 ); what does that "character" represent?
Is a Chinese character? Or Sanskrit? Or Cyrillic?
Is it utf-8; utf16; utf32?
Is it big-endian or little-endian?

It's Unicode. It's HANGZHOU NUMERAL TWENTY, in fact. UTF-8, UTF-16 both represent unicode codepoints, but encode them differently.

When you concatenate a different string to it, the result might depend on the version of Perl. See unicode_strings.

لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ

Comment on Re^5: Character in 'b' format wrapped in unpack

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Re^6: Character in 'b' format wrapped in unpack by BrowserUk (Patriarch) on Mar 29, 2015 at 23:04 UTC
It's Unicode. Great! Then this must be unicode also: perl -MDevel::Peek -E"$x = chr(129).chr(130).chr(42).chr(131).chr(132) +; Dump($x); substr( $x, 2, 1 ) = chr(~0); Dump($x); print $x" \| od -t +x1 SV = PV(0xbadc0) at 0x2c5aa8 REFCNT = 1 FLAGS = (POK,pPOK) PV = 0xb67a8 "\201\202*\203\204"\0 CUR = 5 LEN = 8 SV = PVMG(0x2b1078) at 0x2c5aa8 REFCNT = 2 FLAGS = (SMG,POK,pPOK,UTF8) IV = 0 NV = 0 PV = 0x2b3008 "\302\201\302\202\377\200\217\277\277\277\277\277\277\ +277\277\277\277\302\203\302\204"\0 [UTF8 "\x{81}\x{82}\x{ffffffffffff +ffff}\x{83}\x{84}"] CUR = 21 LEN = 24 MAGIC = 0x3177f8 MG_VIRTUAL = &PL_vtbl_utf8 MG_TYPE = PERL_MAGIC_utf8(w) MG_LEN = -1 Wide character in print at -e line 1. 0000000 c2 81 c2 82 ff 80 8f bf bf bf bf bf bf bf bf bf 0000020 bf c2 83 c2 84 0000025 [download] Broken! With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". I'm with torvalds on this In the absence of evidence, opinion is indistinguishable from prejudice. Agile (and TDD) debunked	[reply] [d/l]
Re^7: Character in 'b' format wrapped in unpack by ikegami (Patriarch) on Mar 29, 2015 at 23:24 UTC
Yes, that code is indeed garbage. Either 0xffffffffffffffff shouldn't have been added to the string, or the string shouldn't have been passed to `print`. Without an encoding layer, it expects the characters to be bytes (0..255).	[reply] [d/l]