Strange string behaviour with character '¡' - php

Please, have a look at this:
$str = '¡hola!'; // '¡' is the spanish opening exclamation mark
echo $str{0}; // prints nothing
echo $str{1}; // prints �
echo $str{2}; // prints h
The php script has UTF-8 encoding and I get the same results executing it as apache module or CLI.
PHP version: 5.4.6
Why I'm getting this strange results?


Indexing a string by [] or {} is not multi-byte safe.
Use multibyte-functions instead, like mb_substr


This is due to the fact that ¡ is actually a multibyte character in UTF, which PHP does not handle properly through array access ([0]). You'll want to look into the multibyte functions instead: http://php.net/manual/en/book.mbstring.php
This should work as you expect:
$str = '¡hola!';
echo mb_substr($str, 0, 1, 'UTF-8'); // prints ¡
echo mb_substr($str, 1, 1, 'UTF-8'); // prints h
echo mb_substr($str, 2, 1, 'UTF-8'); // prints o

Related

PHP: Convert Extended Ascii file to UTF-8

i don't have any chance to get a valid utf-8 as output...
$fx = file_get_contents("Extended Ascii file.txt"); // example only has chr(129), but could be mixed Extended Ascii + UTF8
// not working:
//$fx = html_entity_decode($fx, ENT_QUOTES, "UTF-8");
//$fx = mb_convert_encoding($fx, 'UTF-8', 'ASCII');
//$fx = utf8_encode($fx);
//$fx = iconv('ASCII', 'UTF-8//IGNORE', $fx);
echo '"chr('.ord($fx[0]).')"=>"'.$fx[0].'"<br><br>'; // result: "chr(129)"=>"�"
$fx = strtr($fx, [chr(128)=>'Ç',chr(129)=>'ü',chr(130)=>'é',chr(131)=>'â',chr(132)=>'ä',chr(133)=>'à',chr(134)=>'å',chr(135)=>'ç',chr(136)=>'ê',chr(137)=>'ë',chr(138)=>'è',chr(139)=>'ï',chr(140)=>'î',chr(141)=>'ì',chr(142)=>'Ä',chr(143)=>'Å',chr(144)=>'É',chr(145)=>'æ',chr(146)=>'Æ',chr(147)=>'ô',chr(148)=>'ö',chr(149)=>'ò',chr(150)=>'û',chr(151)=>'ù',chr(152)=>'ÿ',chr(153)=>'Ö',chr(154)=>'Ü',chr(155)=>'ø',chr(156)=>'£',chr(157)=>'Ø',chr(158)=>'×',chr(159)=>'ƒ',chr(160)=>'á',chr(161)=>'í',chr(162)=>'ó',chr(163)=>'ú',chr(164)=>'ñ',chr(165)=>'Ñ',chr(166)=>'ª',chr(167)=>'º',chr(168)=>'¿',chr(169)=>'®',chr(170)=>'¬',chr(171)=>'½',chr(172)=>'¼',chr(173)=>'¡',chr(174)=>'«',chr(175)=>'»',chr(176)=>'░',chr(177)=>'▒',chr(178)=>'▓',chr(179)=>'│',chr(180)=>'┤',chr(181)=>'Á',chr(182)=>'Â',chr(183)=>'À',chr(184)=>'©',chr(185)=>'╣',chr(186)=>'║',chr(187)=>'╗',chr(188)=>'╝',chr(189)=>'¢',chr(190)=>'¥',chr(191)=>'┐',chr(192)=>'└',chr(193)=>'┴',chr(194)=>'┬',chr(195)=>'├',chr(196)=>'─',chr(197)=>'┼',chr(198)=>'ã',chr(199)=>'Ã',chr(200)=>'╚',chr(201)=>'╔',chr(202)=>'╩',chr(203)=>'╦',chr(204)=>'╠',chr(205)=>'═',chr(206)=>'╬',chr(207)=>'¤',chr(208)=>'ð',chr(209)=>'Ð',chr(210)=>'Ê',chr(211)=>'Ë',chr(212)=>'È',chr(213)=>'ı',chr(214)=>'Í',chr(215)=>'Î',chr(216)=>'Ï',chr(217)=>'┘',chr(218)=>'┌',chr(219)=>'█',chr(220)=>'▄',chr(221)=>'¦',chr(222)=>'Ì',chr(223)=>'▀',chr(224)=>'Ó',chr(225)=>'ß',chr(226)=>'Ô',chr(227)=>'Ò',chr(228)=>'õ',chr(229)=>'Õ',chr(230)=>'µ',chr(231)=>'þ',chr(232)=>'Þ',chr(233)=>'Ú',chr(234)=>'Û',chr(235)=>'Ù',chr(236)=>'ý',chr(237)=>'Ý',chr(238)=>'¯',chr(239)=>'´',chr(240)=>'≡',chr(241)=>'±',chr(242)=>'‗',chr(243)=>'¾',chr(244)=>'¶',chr(245)=>'§',chr(246)=>'÷',chr(247)=>'¸',chr(248)=>'°',chr(249)=>'¨',chr(250)=>'·',chr(251)=>'¹',chr(252)=>'³',chr(253)=>'²',chr(254)=>'■',chr(255)=>'nbsp']);
echo '"chr('.ord($fx[0]).')"=>"'.$fx[0].'"<br><br>'; // result: "chr(195)"=>"�"
How to convert or remove � ?
28.05.2020 Update: Solution found, thanks to Andrea Pollini!
Some notes:
iconv('UTF-8', 'UTF-8//IGNORE', $fx); // IGNORE is broken in PHP since - https://www.php.net/manual/en/function.iconv.php#108643 - use mb_convert_encoding
Here was my real problem (i figured it out later after many tests):
$P["T"] .= $text; // here was the problem, array is converting strings... (don't know why?)
changed to:
ini_set('mbstring.substitute_character', "none"); // mb_convert_encoding set remove unknown
$P["T"] .= mb_convert_encoding($text, 'UTF-8', 'UTF-8');
Now it's working. But if somebody knows why arrays are converting strings and how to disable that, would be great. :)

first configure in order to discard extended characters
<?php
ini_set('mbstring.substitute_character', "none");
?>
next you can use mb_convert_encoding
mb_convert_encoding($fx, "UTF-8", mb_detect_encoding($fx, "UTF-8, ISO-8859-1, ISO-8859-15", true));
you can add the encoding you need in mb_detect_encoding

PHP Default String Encoding

Could someone explain why the output is ASCII in the last three tests below?
I get the same results on my own system, PHPTester.net, and PhpFiddle.org.
echo mb_internal_encoding(); // UTF-8
$str = 'foobar';
echo mb_check_encoding($str, 'UTF-8'); // true
echo mb_detect_encoding($str); // ASCII
$encoded = utf8_encode($str);
echo mb_detect_encoding($encoded); // ASCII
$converted = mb_convert_encoding($str, 'UTF-8');
echo mb_detect_encoding($converted); // ASCII

That would be because there are no characters in foobar that cannot be represented in ASCII.
mb_check_encoding($str, 'UTF-8') works because ASCII text is innately compatible with UTF-8 (deliberately so)
But in the absence of multi-byte characters, there's no discernible difference between the two. Proof of this: 'foobar' === utf8_encode('foobar') // true

How to convert a Unicode text-block to UTF-8 (HEX) code point?

I have a Unicode text-block, like this:
ụ
ư
ứ
Ỳ
Ỷ
Ỵ
Đ
Now, I want to convert this orginal Unicode text-block into a text-block of UTF-8 (HEX) code point (see the Hexadecimal UTF-8 column, on this page: https://en.wikipedia.org/wiki/UTF-8), by PHP; like this:
\xe1\xbb\xa5
\xc6\xb0
\xe1\xbb\xa9
\xe1\xbb\xb2
\xe1\xbb\xb6
\xe1\xbb\xb4
\xc4\x90
Not like this:
0x1EE5
0x01B0
0x1EE9
0x1EF2
0x1EF6
0x1EF4
0x0110
Is there any way to do it, by PHP?
I have read this topic (PHP: Convert unicode codepoint to UTF-8). But, it is not similar to my question.
I am sorry, I don't know much about Unicode.

I think you're looking for the bin2hex() function:
Convert binary data into hexadecimal representation
And format by prepending \x to each byte (00-FF)
function str_hex_format ($bin) {
return '\x'.implode('\x', str_split(bin2hex($bin), 2));
}
For your sample:
// utf8 encoded input
$arr = ["ụ","ư","ứ","Ỳ","Ỷ","Ỵ","Đ"];
foreach($arr AS $v)
echo $v . " => " . str_hex_format($v) . "\n";
See test at eval.in (link expires)
ụ => \xe1\xbb\xa5
ư => \xc6\xb0
ứ => \xe1\xbb\xa9
Ỳ => \xe1\xbb\xb2
Ỷ => \xe1\xbb\xb6
Ỵ => \xe1\xbb\xb4
Đ => \xc4\x90
Decode example: $str = str_hex_format("ụưứỲỶỴĐ"); echo $str;
\xe1\xbb\xa5\xc6\xb0\xe1\xbb\xa9\xe1\xbb\xb2\xe1\xbb\xb6\xe1\xbb\xb4\xc4\x90
echo hex2bin(str_replace('\x', "", $str));
ụưứỲỶỴĐ
For more info about escape sequence \x in double quoted strings see php manual.

PHP treats strings as arrays of characters, regardless of encoding. If you don't need to delimit the UTF8 characters, then something like this works:
$str='ụưứỲỶỴĐ';
foreach(str_split($str) as $char)
echo '\x'.str_pad(dechex(ord($char)),'0',2,STR_PAD_LEFT);
Output:
\xe1\xbb\xa5\xc6\xb0\xe1\xbb\xa9\xe1\xbb\xb2\xe1\xbb\xb6\xe1\xbb\xb4\xc4\x90
If you need to delimit the UTF8 characters (i.e. with a newline), then you'll need something like this:
$str='ụưứỲỶỴĐ';
foreach(array_slice(preg_split('~~u',$str),1,-1) as $UTF8char){ // split before/after every UTF8 character and remove first/last empty string
foreach(str_split($UTF8char) as $char)
echo '\x'.str_pad(dechex(ord($char)),'0',2,STR_PAD_LEFT);
echo "\n"; // delimiter
}
Output:
\xe1\xbb\xa5
\xc6\xb0
\xe1\xbb\xa9
\xe1\xbb\xb2
\xe1\xbb\xb6
\xe1\xbb\xb4
\xc4\x90
This splits the string into UTF8 characters using preg_split and the u flag. Since preg_split returns the empty string before the first character and the empty string after the last character, we need to array_slice the first and last characters. This can be easily modified to return an array, for example.
Edit:
A more "correct" way to do this is this:
echo trim(json_encode(utf8_encode('ụưứỲỶỴĐ')),'"');

The main thing you need to do is to tell PHP to interpret the incoming Unicode characters correctly. Once you do that, you can then convert them to UTF-8 and then to hex as needed.
This code frag takes your example character in Unicode, converts them to UTF-8, and then dumps the hex representation of those characters.
<?php
// Hex equivalent of "ụưứỲỶỴĐ" in Unicode
$unistr = "\x1E\xE5\x01\xB0\x1E\xE9\x1E\xF2\x1E\xF6\x1E\xF4\x01\x10";
echo " length=" . mb_strlen($unistr, 'UCS-2BE') . "\n";
// Here's the key statement, convert from Unicode 16-bit to UTF-8
$utf8str = mb_convert_encoding($unistr, "UTF-8", 'UCS-2BE');
echo $utf8str . "\n";
for($i=0; $i < mb_strlen($utf8str, 'UTF-8'); $i++) {
$c = mb_substr($utf8str, $i, 1, 'UTF-8');
$hex = bin2hex($c);
echo $c . "\t" . $hex . "\t" . preg_replace("/([0-9a-f]{2})/", '\\\\x\\1', $hex) . "\n";
}
?>
Produces
length=7
ụưứỲỶỴĐ
ụ e1bba5 \xe1\xbb\xa5
ư c6b0 \xc6\xb0
ứ e1bba9 \xe1\xbb\xa9
Ỳ e1bbb2 \xe1\xbb\xb2
Ỷ e1bbb6 \xe1\xbb\xb6
Ỵ e1bbb4 \xe1\xbb\xb4
Đ c490 \xc4\x90

String cannot start with Å, Ä, Ö

Why is it, when i shorten a string. Letter "å, ä, ö" becomes "?"?
If i use the Name "Örjan" it becomes "Orjan".
But when i use "Björn", it works all fine?
PHP
//Create initials
$usr_fname_f_letter = $_POST['usr_fname'];
$usr_fname_f_letter = $usr_fname_f_letter[0];
$usr_lname_f_letter = $_POST['usr_lname'];
$usr_lname_f_letter = $usr_lname_f_letter[0];
$usr_inits = $usr_fname_f_letter .= $usr_lname_f_letter;
echo $_POST['usr_fname'];
echo '<br>';
echo $_POST['usr_lname'];
echo '<br>';
echo $usr_fname_f_letter;
echo '<br>';
echo $usr_lname_f_letter;
echo '<br>';
echo $usr_inits;
echo '<br>';
RESULT
Örjan
Björnsson
�B
B
�B

$usr_fname_f_letter = $usr_fname_f_letter[0];
simply takes the first (zero offset) byte from $usr_fname_f_letter; but you're using a multibyte character set and that's like chopping part of a character in half.
Use
mb_substr($usr_fname_f_letter, 0, 1, 'UTF-8')
because the mb_* functions are multi-byte character set aware; and work in characters, not in bytes

I assume your encoding is utf-8 and you are probably printing only part of a multibyte character.
Try to use multibyte safe function, like mb_substr:
mb_substr($str, 0, 1, "UTF-8");

Detecting the right character encoding in PHP?

I'm trying to detect the character encoding of a string but I can't get the right result.
For example:
$str = "€ ‚ ƒ „ …" ;
$str = mb_convert_encoding($str, 'Windows-1252' ,'HTML-ENTITIES') ;
// Now $str should be a Windows-1252-encoded string.
// Let's detect its encoding:
echo mb_detect_encoding($str,'Windows-1252, ISO-8859-1, UTF-8') ;
That code outputs ISO-8859-1 but it should be Windows-1252.
What's wrong with this?
EDIT:
Updated example, in response to #raina77ow.
$str = "€‚ƒ„…" ; // no white-spaces
$str = mb_convert_encoding($str, 'Windows-1252' ,'HTML-ENTITIES') ;
$str = "Hello $str" ; // let's add some ascii characters
echo mb_detect_encoding($str,'Windows-1252, ISO-8859-1, UTF-8') ;
I get the wrong result again.

The problem with Windows-1252 in PHP is that it will almost never be detected, because as soon as your text contains any characters outside of 0x80 to 0x9f, it will not be detected as Windows-1252.
This means that if your string contains a normal ASCII letter like "A", or even a space character, PHP will say that this is not valid Windows-1252 and, in your case, fall back to the next possible encoding, which is ISO 8859-1. This is a PHP bug, see https://bugs.php.net/bug.php?id=64667.

Although strings encoded with ISO-8859-1 and CP-1252 have different byte code representation:
<?php
$str = "€ ‚ ƒ „ …" ;
foreach (array('Windows-1252', 'ISO-8859-1') as $encoding)
{
$new = mb_convert_encoding($str, $encoding, 'HTML-ENTITIES');
printf('%15s: %s detected: %10s explicitly: %10s',
$encoding,
implode('', array_map(function($x) { return dechex(ord($x)); }, str_split($new))),
mb_detect_encoding($new),
mb_detect_encoding($new, array('ISO-8859-1', 'Windows-1252'))
);
echo PHP_EOL;
}
Results:
Windows-1252: 802082208320842085 detected: explicitly: ISO-8859-1
ISO-8859-1: 3f203f203f203f203f detected: ASCII explicitly: ISO-8859-1
...from what we can see here it looks like there is problem with second paramater of mb_detect_encoding. Using mb_detect_order instead of parameter yields very similar results.

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