Convert hex values to characters - perl

I have strings like: "Film-DVD \x{bb}Once / The Swell Season (Collector's Edition\x{ab} John Carney" which are the result of Data::Dumper.
Now I want the hex-values \x{bb}, \x{ab} to be replaced with corresponding characters » and «.
I already tried:
$a =~ s/\\x\{(.{2})\}/chr(hex($1))/eg;
But this returns me "Film-DVD �Once / The Swell Season (Collector's Edition� John Carney"
Do you have any ideas what i could do?

The code you posted is correct.
The problem appears to be that you forgot to tell Perl to encode your output. This is normally done using
use open ':std', ':encoding(UTF-8)';

Related

Convert roman to words/number in Perl

I have an input from a file, and I need to convert the roman numerals in the input to words or integers.
In my article there are combination of strings, numbers, roman numbers, but i need only to change the roman to number, i used convert::number::roman but it takes whole text and of course its not roman
When I use roman, it should convert the value we put in:
$roman = roman(13);
$arabic = arabic($roman) if isroman($roman);
Please advise me?
If I understand the problem, you are trying to convert roman numerals contained inside a larger text. The simplest way to do this, though rather brute-force, would be to do an eval substitution. For example.
#!/usr/bin/env perl
use strict;
use warnings;
use Text::Roman 'roman2int';
my $text = <<'END';
Tim: Let's meet at half past VI.
Toady: Hmm, no good. How about quarter to IX?
END
$text =~ s/\b(\w+)\b/roman2int($1) || $1/ge;
print $text;
Since roman2int returns undef on failure to convert, we simply try to convert each word and if it succeeds use it else leave the original word. This of course will have problems, like words that are valid roman numerals, like I, IV, ID, DIM, etc etc. This is of course, up to you.
On a related note, it might be fun to run the code over a dictionary and see how many words are valid roman numerals :-)

Filtering microsoft 1252 characters out of an ASCII text file opened in utf8 mode in Perl

I have a reasonable size flat file database of text documents mostly saved in 8859 format which have been collected through a web form (using Perl scripts). Up until recently I was negotiating the common 1252 characters (curly quotes, apostrophes etc.) with a simple set of regex's:
$line=~s/\x91/\&\#8216\;/g; # smart apostrophe left
$line=~s/\x92/\&\#8217\;/g; # smart apostrophe right
... etc.
However since I decided I ought to be going Unicode, and have converted all my scripts to read in and output utf8 (which works a treat for all new material), the regex for these (existing) 1252 characters no longer works and my Perl html output outputs literally the 4 characters: '\x92' and '\x93' etc. (at least that's how it appears on a browser in utf8 mode, downloading (ftp not http) and opening in a text editor (textpad) it's different, a single undefined character remains, and opening the output file in Firefox default (no content type header) 8859 mode renders the correct character).
The new utf8 pragmas at the start of the script are:
use CGI qw(-utf8);
use open IO => ':utf8';
I understand this is due to utf8 mode making the characters double byte instead of single byte and applies to those chars in the 0x80 to 0xff range, having read up the article on wikibooks relating to this, however I was non the wiser as to how to filter them. Ideally I know I ought to resave all the documents in utf8 mode (since the flat file database now contains a mixture of 8859 and utf8), however I will need some kind of filter in the first place if I'm going to do this anyway.
And I could be wrong as to the 2-byte storage internally, since it did seem to imply that Perl handles stuff very differently according to various circumstances.
If anybody could provide me with a regex solution I would be very grateful. Or some other method. I have been tearing my hair out for weeks on this with various attempts and failed hacking. There's simply about 6 1252 characters that commonly need replacing, and with a filter method I could resave the whole flippin lot in utf8 and forget there ever was a 1252...
Encoding::FixLatin was specifically written to help fix data broken in the same manner as yours.
Ikegami already mentioned the Encoding::FixLatin module.
Another way to do it, if you know that each string will be either UTF-8 or CP1252, but not a mixture of both, is to read it as a binary string and do:
unless ( utf8::decode($string) ) {
require Encode;
$string = Encode::decode(cp1252 => $string);
}
Compared to Encoding::FixLatin, this has two small advantages: a slightly lower chance of misinterpreting CP1252 text as UTF-8 (because the entire string must be valid UTF-8) and the possibility of replacing CP1252 with some other fallback encoding. A corresponding disadvantage is that this code could fall back to CP1252 on strings that are not entirely valid UTF-8 for some other reason, such as because they were truncated in the middle of a multi-byte character.
You could also use Encode.pm's support for fallback.
use Encode qw[decode];
my $octets = "\x91 Foo \xE2\x98\xBA \x92";
my $string = decode('UTF-8', $octets, sub {
my ($ordinal) = #_;
return decode('Windows-1252', pack 'C', $ordinal);
});
printf "<%s>\n",
join ' ', map { sprintf 'U+%.4X', ord $_ } split //, $string;
Output:
<U+2018 U+0020 U+0046 U+006F U+006F U+0020 U+263A U+0020 U+2019>
Did you recode the data files? If not, opening them as UTF-8 won't work. You can simply open them as
open $filehandle, '<:encoding(cp1252)', $filename or die ...;
and everything (tm) should work.
If you did recode, something seem to have gone wrong, and you need to analyze what it is, and fix it. I recommend using hexdump to find out what actually is in a file. Text consoles and editors sometimes lie to you, hexdump never lies.

Why does Perl's LWP gives me a different encoding than the original website?

Lets say i have this code:
use strict;
use LWP qw ( get );
my $content = get ( "http://www.msn.co.il" );
print STDERR $content;
The error log shows something like "\xd7\x9c\xd7\x94\xd7\x93\xd7\xa4\xd7\xa1\xd7\x94"
which i'm guessing it's utf-16 ?
The website's encoding is with
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=windows-1255">
so why these characters appear and not the windows-1255 chars ?
And, another weird thing is that i have two servers:
the first server returning CP1255 chars and i can simply convert it to utf8,
and the current server gives me these chars and i can't do anything with it ...
is there any configuration file in apache/perl/module that is messing up the encoding ?
forcing something ... ?
The result in my website at the second server, is that the perl file and the headers are all utf8, so when i write text that aren't english chars, the content from the example above is showing ok ( even though it's weird utf chars ) but my own static text are look like "×ס'××ר××:"
One more thing that i tested is ...
Through perl:
my $content = `curl "http://www.anglo-saxon.co.il"`;
I get utf8 encoding.
Through Bash:
curl "http://www.anglo-saxon.co.il"
and here i get CP1255 ( Windows-1255 ) encoding ...
Also,
when i run the script in bash - it gives CP1255, and when run it through the web - then it's utf8 again ...
fixed the problem by changin the content from utf8 - to what is supposed to, and then back to utf8:
use Text::Iconv;
my $converter = Text::Iconv->new("utf8", "CP1255");
$content=$converter->convert($content);
my $converter = Text::Iconv->new("CP1255", "utf8");
$content=$converter->convert($content);
All of this manual encoding and decoding is unnecessary. The HTML is lying to you when it says that the page is encoded in windows-1255; the server says it's serving UTF-8, and it is. Blame Microsoft HTML-generation tools.
Anyway, since the server does return the correct encoding, this works:
my $response = LWP::UserAgent->new->get("http://www.msn.co.il/");
my $content = $res->decoded_content;
$content is now a perl character string, ready to do whatever you need. If you want to convert it to some other encoding, then calling Encode::encode on it is appropriate; do not use Encode::decode as it's already been decoded once.
http://www.msn.co.il is in UTF-8, and indicates that properly. The string "\xd7\x9c\xd7\x94\xd7\x93\xd7\xa4\xd7\xa1\xd7\x94" is also proper UTF-8 (להדפסה). I don't see the problem.
I think your second problem is due to you mixing different encodings (UTF-8 and Windows-1252). You might want to encode/decode your strings properly.
First, note that you should import get from LWP::Simple. Second, everything works fine with:
#!/usr/bin/perl
use strict; use warnings;
use LWP::Simple qw ( getstore );
getstore 'http://www.msn.co.il', 'test.html';
which indicates to me that the problem is the encoding of the filehandle to which you are sending the output.
The string with the hex values that you gave appears to be a UTF-8 encoding. You are getting this because Perl ‘likes to’ use UTF-8 when it deals with strings. The LWP::Simple->get() method automatically decodes the content from the server which includes undoing any Content-Encoding as well as converting to UTF-8.
You could dig into the internals and get a version that does change the character encoding (see HTTP::Message's decoded_content, which is used by HTTP::Response's decoded_content, which you can get from LWP::UserAgent's get). But it may be easier to re-encode the data in your desired encoding with something like
use Encode;
...;
$cp1255_bytes = encode('CP1255', decode('UTF_8', $utf8_bytes));
The mixed readable/garbage characters you see are due to mixing multiple, incompatible encodings in the same stream. Probably the stream is labeled as UTF-8 but you are putting CP1255 encoded characters into it. You either need to label the stream as CP1255 and put only CP1255-encoded data into it, or label it as UTF-8 and put only UTF-8-encoded data into it. Remind yourself that bytes are not characters and convert between them appropriately.

How can I create a Unicode character from its bytes when they are stored in different variables in Perl?

I am trying to Convert hex representations of Unicode characters to the characters they represent. The following example works fine:
#!/usr/bin/perl
use Encode qw( encode decode );
binmode(STDOUT, ':encoding(utf-8)');
my $encoded = encode('utf8', "\x{e382}\x{af}");
eval { $encoded = decode('utf8', $encoded, Encode::FB_CROAK); 1 }
or print("coaked\n");
print "$encoded\n";
However the hex digits are stored in 3 variables.
So if i replace the encode line with this:
my $encoded = encode('utf8', "\x{${byte1}${byte2}}\x{${byte3}}");
where
my $byte1 = "e3"; my $byte2 = "82"; my $byte3 = "af";
It fails as it tries to evaluate the \x immediately and sees the $ sign and { as characters.
Does anyone know how to get around this.
Instead of
my $encoded = encode('utf8', "\x{${byte1}${byte2}}\x{${byte3}}");
You can use
my $encoded = encode('utf8', chr(hex($byte1 . $byte2)) . chr(hex($byte3)));
hex() converts from hexadecimal, and chr() returns the unicode character for a given code point.
[Edit:]
Not related to your question, but I noticed you mix utf-8 and utf8 in your program. I don't know if this is a typo, but you should be a ware that these are not the same things in Perl:
utf-8 (with hyphen, case insensitive) is what the UTF-8 standard says, whereas utf8 (no hyphen, also case insensitive) is Perls internal encoding, which is more loosely defined (it allows codepoints that are not valid unicode codepoints). In general, you should stick to utf-8 (perlunifaq has the details).
trendel's answer seems pretty good, but Encode::Escape offers an alternative solution:
use Encode::Escape::Unicode;
my $hex = '263a';
my $escaped = "\\x{" . $hex . "}\n";
print encode 'utf8', decode 'unicode-escape', $escaped;
First off, think hard about why you ended up with three variables, $byte1, $byte2, $byte3, each holding one byte's worth of data, as a two-character string, in hex. This part of your program seems hard because of a poor design decision further up. Fix that bad decision, and this part of the code will fall out naturally.
That being said, what you want to do, I think, is this:
my $byte1 = "e3"; my $byte2 = "82"; my $byte3 = "af";
my $str = chr(hex($byte1 . $byte2)) . chr(hex($byte3))
The encoding stuff is a red herring; you shouldn't be worrying about encodings in the middle of your program, only when you do IO.
I'm assuming in the above that you want to get out a two character string, U+E382 followed by U+AF. That's what you actually asked for. However, since there is no U+E382, since it's in the middle of the private use area, that's probably not what you actually wanted. Please try to reword the question? Perhaps ask a more basic question, and describe what you are trying to achieve, rather then how you are going about trying to do it?

How can I convert a binary number into a string character using Perl script?

How can I convert a binary number into a string character using Perl script?
If you mean binary to ASCII like this webpage, this should do the trick:
#!/usr/bin/perl
$binarySample = "01010100011001010111001101110100"; # "Test" in binary
$chars = length($binarySample);
#packArray = pack("B$chars",$binarySample);
print "#packArray\n";
output:
Test
chr(0x41) or chr(65) turns the number 65 (41 in hex) into the letter "A", is this what you are looking for?
Strings can contain either binary data or text characters; nothing special is needed.
Tell us more about what you are trying to do, and that might shed some light on what you mean by "convert" or "binary".