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.\" Automatically generated by Pod::Man 4.11 (Pod::Simple 3.35) .\" .\" Standard preamble: .\" ======================================================================== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. \*(C+ will .\" give a nicer C++. Capital omega is used to do unbreakable dashes and .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff, .\" nothing in troff, for use with C<>. .tr \(*W- .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} .el\{\ . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . ds C` . ds C' 'br\} .\" .\" Escape single quotes in literal strings from groff's Unicode transform. .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" .\" If the F register is >0, we'll generate index entries on stderr for .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index .\" entries marked with X<> in POD. Of course, you'll have to process the .\" output yourself in some meaningful fashion. .\" .\" Avoid warning from groff about undefined register 'F'. .de IX .. .nr rF 0 .if \n(.g .if rF .nr rF 1 .if (\n(rF:(\n(.g==0)) \{\ . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF .\" .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2). .\" Fear. Run. Save yourself. No user-serviceable parts. . \" fudge factors for nroff and troff .if n \{\ . ds #H 0 . ds #V .8m . ds #F .3m . ds #[ \f1 . ds #] \fP .\} .if t \{\ . ds #H ((1u-(\\\\n(.fu%2u))*.13m) . ds #V .6m . ds #F 0 . ds #[ \& . ds #] \& .\} . \" simple accents for nroff and troff .if n \{\ . ds ' \& . ds ` \& . ds ^ \& . ds , \& . ds ~ ~ . ds / .\} .if t \{\ . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u" . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u' . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u' . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u' . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u' . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u' .\} . \" troff and (daisy-wheel) nroff accents .ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V' .ds 8 \h'\*(#H'\(*b\h'-\*(#H' .ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#] .ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H' .ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u' .ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#] .ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#] .ds ae a\h'-(\w'a'u*4/10)'e .ds Ae A\h'-(\w'A'u*4/10)'E . \" corrections for vroff .if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u' .if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u' . \" for low resolution devices (crt and lpr) .if \n(.H>23 .if \n(.V>19 \ \{\ . ds : e . ds 8 ss . ds o a . ds d- d\h'-1'\(ga . ds D- D\h'-1'\(hy . ds th \o'bp' . ds Th \o'LP' . ds ae ae . ds Ae AE .\} .rm #[ #] #H #V #F C .\" ======================================================================== .\" .IX Title "Encode::Guess 3" .TH Encode::Guess 3 "2019-10-24" "perl v5.30.2" "Perl Programmers Reference Guide" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "NAME" Encode::Guess \-\- Guesses encoding from data .SH "SYNOPSIS" .IX Header "SYNOPSIS" .Vb 1 \& # if you are sure $data won\*(Aqt contain anything bogus \& \& use Encode; \& use Encode::Guess qw/euc\-jp shiftjis 7bit\-jis/; \& my $utf8 = decode("Guess", $data); \& my $data = encode("Guess", $utf8); # this doesn\*(Aqt work! \& \& # more elaborate way \& use Encode::Guess; \& my $enc = guess_encoding($data, qw/euc\-jp shiftjis 7bit\-jis/); \& ref($enc) or die "Can\*(Aqt guess: $enc"; # trap error this way \& $utf8 = $enc\->decode($data); \& # or \& $utf8 = decode($enc\->name, $data) .Ve .SH "ABSTRACT" .IX Header "ABSTRACT" Encode::Guess enables you to guess in what encoding a given data is encoded, or at least tries to. .SH "DESCRIPTION" .IX Header "DESCRIPTION" By default, it checks only ascii, utf8 and \s-1UTF\-16/32\s0 with \s-1BOM.\s0 .PP .Vb 1 \& use Encode::Guess; # ascii/utf8/BOMed UTF .Ve .PP To use it more practically, you have to give the names of encodings to check (\fIsuspects\fR as follows). The name of suspects can either be canonical names or aliases. .PP \&\s-1CAVEAT:\s0 Unlike \s-1UTF\-\s0(16|32), \s-1BOM\s0 in utf8 is \s-1NOT AUTOMATICALLY STRIPPED.\s0 .PP .Vb 2 \& # tries all major Japanese Encodings as well \& use Encode::Guess qw/euc\-jp shiftjis 7bit\-jis/; .Ve .PP If the \f(CW$Encode::Guess::NoUTFAutoGuess\fR variable is set to a true value, no heuristics will be applied to \s-1UTF8/16/32,\s0 and the result will be limited to the suspects and \f(CW\*(C`ascii\*(C'\fR. .IP "Encode::Guess\->set_suspects" 4 .IX Item "Encode::Guess->set_suspects" You can also change the internal suspects list via \f(CW\*(C`set_suspects\*(C'\fR method. .Sp .Vb 2 \& use Encode::Guess; \& Encode::Guess\->set_suspects(qw/euc\-jp shiftjis 7bit\-jis/); .Ve .IP "Encode::Guess\->add_suspects" 4 .IX Item "Encode::Guess->add_suspects" Or you can use \f(CW\*(C`add_suspects\*(C'\fR method. The difference is that \&\f(CW\*(C`set_suspects\*(C'\fR flushes the current suspects list while \&\f(CW\*(C`add_suspects\*(C'\fR adds. .Sp .Vb 5 \& use Encode::Guess; \& Encode::Guess\->add_suspects(qw/euc\-jp shiftjis 7bit\-jis/); \& # now the suspects are euc\-jp,shiftjis,7bit\-jis, AND \& # euc\-kr,euc\-cn, and big5\-eten \& Encode::Guess\->add_suspects(qw/euc\-kr euc\-cn big5\-eten/); .Ve .ie n .IP "Encode::decode(""Guess"" ...)" 4 .el .IP "Encode::decode(``Guess'' ...)" 4 .IX Item "Encode::decode(Guess ...)" When you are content with suspects list, you can now .Sp .Vb 1 \& my $utf8 = Encode::decode("Guess", $data); .Ve .IP "Encode::Guess\->guess($data)" 4 .IX Item "Encode::Guess->guess($data)" But it will croak if: .RS 4 .IP "\(bu" 4 Two or more suspects remain .IP "\(bu" 4 No suspects left .RE .RS 4 .Sp So you should instead try this; .Sp .Vb 1 \& my $decoder = Encode::Guess\->guess($data); .Ve .Sp On success, \f(CW$decoder\fR is an object that is documented in Encode::Encoding. So you can now do this; .Sp .Vb 1 \& my $utf8 = $decoder\->decode($data); .Ve .Sp On failure, \f(CW$decoder\fR now contains an error message so the whole thing would be as follows; .Sp .Vb 3 \& my $decoder = Encode::Guess\->guess($data); \& die $decoder unless ref($decoder); \& my $utf8 = $decoder\->decode($data); .Ve .RE .IP "guess_encoding($data, [, \fIlist of suspects\fR])" 4 .IX Item "guess_encoding($data, [, list of suspects])" You can also try \f(CW\*(C`guess_encoding\*(C'\fR function which is exported by default. It takes \f(CW$data\fR to check and it also takes the list of suspects by option. The optional suspect list is \fInot reflected\fR to the internal suspects list. .Sp .Vb 5 \& my $decoder = guess_encoding($data, qw/euc\-jp euc\-kr euc\-cn/); \& die $decoder unless ref($decoder); \& my $utf8 = $decoder\->decode($data); \& # check only ascii, utf8 and UTF\-(16|32) with BOM \& my $decoder = guess_encoding($data); .Ve .SH "CAVEATS" .IX Header "CAVEATS" .IP "\(bu" 4 Because of the algorithm used, \s-1ISO\-8859\s0 series and other single-byte encodings do not work well unless either one of \s-1ISO\-8859\s0 is the only one suspect (besides ascii and utf8). .Sp .Vb 5 \& use Encode::Guess; \& # perhaps ok \& my $decoder = guess_encoding($data, \*(Aqlatin1\*(Aq); \& # definitely NOT ok \& my $decoder = guess_encoding($data, qw/latin1 greek/); .Ve .Sp The reason is that Encode::Guess guesses encoding by trial and error. It first splits \f(CW$data\fR into lines and tries to decode the line for each suspect. It keeps it going until all but one encoding is eliminated out of suspects list. \s-1ISO\-8859\s0 series is just too successful for most cases (because it fills almost all code points in \ex00\-\exff). .IP "\(bu" 4 Do not mix national standard encodings and the corresponding vendor encodings. .Sp .Vb 3 \& # a very bad idea \& my $decoder \& = guess_encoding($data, qw/shiftjis MacJapanese cp932/); .Ve .Sp The reason is that vendor encoding is usually a superset of national standard so it becomes too ambiguous for most cases. .IP "\(bu" 4 On the other hand, mixing various national standard encodings automagically works unless \f(CW$data\fR is too short to allow for guessing. .Sp .Vb 6 \& # This is ok if $data is long enough \& my $decoder = \& guess_encoding($data, qw/euc\-cn \& euc\-jp shiftjis 7bit\-jis \& euc\-kr \& big5\-eten/); .Ve .IP "\(bu" 4 \&\s-1DO NOT PUT TOO MANY SUSPECTS\s0! Don't you try something like this! .Sp .Vb 2 \& my $decoder = guess_encoding($data, \& Encode\->encodings(":all")); .Ve .PP It is, after all, just a guess. You should alway be explicit when it comes to encodings. But there are some, especially Japanese, environment that guess-coding is a must. Use this module with care. .SH "TO DO" .IX Header "TO DO" Encode::Guess does not work on \s-1EBCDIC\s0 platforms. .SH "SEE ALSO" .IX Header "SEE ALSO" Encode, Encode::Encoding