Php get string bytes

Строка в байтовый массив в php

Как я могу получить массив байтов из некоторой строки, которая может содержать числа, буквы и т. Д.? Если вы знакомы с Java, я ищу ту же функциональность метода getBytes ().

Я попробовал такой сниппет:

но безуспешно, поэтому любая помощь будет оценена по достоинству.

PS: Зачем мне это вообще ?? Ну, мне нужно отправить массив байтов через fputs () на сервер, написанный на Java …

@Sparr прав, но я предполагаю, что вы ожидали массив byte[] например byte[] в C #. Это то же самое решение, что и Sparr, но вместо HEX вы ожидали int presentation ( диапазон от 0 до 255 ) каждого char . Вы можете сделать следующее:

$byte_array = unpack('C*', 'The quick fox jumped over the lazy brown dog'); var_dump($byte_array); // $byte_array should be int[] which can be converted // to byte[] in C# since values are range of 0 - 255 

Используя var_dump вы можете видеть, что элементы являются int ( not string ).

 array(44) < [1]=>int(84) [2]=> int(104) [3]=> int(101) [4]=> int(32) [5]=> int(113) [6]=> int(117) [7]=> int(105) [8]=> int(99) [9]=> int(107) [10]=> int(32) [11]=> int(102) [12]=> int(111) [13]=> int(120) [14]=> int(32) [15]=> int(106) [16]=> int(117) [17]=> int(109) [18]=> int(112) [19]=> int(101) [20]=> int(100) [21]=> int(32) [22]=> int(111) [23]=> int(118) [24]=> int(101) [25]=> int(114) [26]=> int(32) [27]=> int(116) [28]=> int(104) [29]=> int(101) [30]=> int(32) [31]=> int(108) [32]=> int(97) [33]=> int(122) [34]=> int(121) [35]=> int(32) [36]=> int(98) [37]=> int(114) [38]=> int(111) [39]=> int(119) [40]=> int(110) [41]=> int(32) [42]=> int(100) [43]=> int(111) [44]=> int(103) > 

print_r(unpack("H*","The quick fox jumped over the lazy brown dog")) Array ( [1] => 54686520717569636b20666f78206a756d706564206f76657220746865206c617a792062726f776e20646f67 ) 

При необходимости вы можете разделить результат на два столбца с шестнадцатеричным символом.

Вы можете попробовать следующее:

$in_str = 'this is a test'; $hex_ary = array(); foreach (str_split($in_str) as $chr) < $hex_ary[] = sprintf("%02X", ord($chr)); >echo implode(' ',$hex_ary); 

В PHP строки – это потоки. Что именно ты пытаешься сделать?

Ps. Зачем мне это вообще ?? Ну, мне нужно отправить через fputs () bytearray на сервер, написанный в java …

fputs принимает строку в качестве аргумента. Скорее всего, вам просто нужно передать свою строку. На стороне Java вещи вы должны декодировать данные в любой кодировке, которую вы используете в php (по умолчанию iso-8859-1).

PHP не имеет явного типа byte , но его string уже является эквивалентом массива байтов Java. Вы можете безопасно писать fputs($connection, «The quick brown fox …») . Единственное, что вы должны знать, это кодирование символов, они должны быть одинаковыми с обеих сторон. Используйте mb_convert_encoding (), когда вы сомневаетесь.

Я нашел несколько функций, определенных в http://tw1.php.net/unpack , очень полезными.
Они могут скрывать строку в байтовый массив и наоборот.

Возьмите byteStr2byteArray () в качестве примера:

 $msg = "abcdefghijk"; $byte_array = byteStr2byteArray($msg); for($i=0;$i ?> 

Источник

How to Get the Byte Values of a String in PHP

How can I get the single bytes from a multibyte PHP string variable in a binary-safe way?

you can get a bytearray by unpacking the utf8_encoded string $a:

$a = utf8_encode('Fön');
$b = unpack('C*', $a); 
var_dump($b);

used format C* for «unsigned char»

• String to byte array in php
• http://www.php.net/manual/en/function.unpack.php
• http://www.php.net/manual/en/function.pack.php

String to byte array in php

@Sparr is right, but I guess you expected byte array like byte[] in C#. It’s the same solution as Sparr did but instead of HEX you expected int presentation (range from 0 to 255) of each char . You can do as follows:

$byte_array = unpack('C*', 'The quick fox jumped over the lazy brown dog');
var_dump($byte_array); // $byte_array should be int[] which can be converted 
// to byte[] in C# since values are range of 0 - 255

By using var_dump you can see that elements are int (not string ).

 array(44) < [1]=>int(84) [2]=> int(104) [3]=> int(101) [4]=> int(32)
[5]=> int(113) [6]=> int(117) [7]=> int(105) [8]=> int(99) [9]=> int(107)
[10]=> int(32) [11]=> int(102) [12]=> int(111) [13]=> int(120) [14]=> int(32)
[15]=> int(106) [16]=> int(117) [17]=> int(109) [18]=> int(112) [19]=> int(101)
[20]=> int(100) [21]=> int(32) [22]=> int(111) [23]=> int(118) [24]=> int(101)
[25]=> int(114) [26]=> int(32) [27]=> int(116) [28]=> int(104) [29]=> int(101)
[30]=> int(32) [31]=> int(108) [32]=> int(97) [33]=> int(122) [34]=> int(121)
[35]=> int(32) [36]=> int(98) [37]=> int(114) [38]=> int(111) [39]=> int(119)
[40]=> int(110) [41]=> int(32) [42]=> int(100) [43]=> int(111) [44]=> int(103) >

Be careful: the output array is of 1-based index (as it was pointed out in the comment)

PHP Read Byte Range from String or File

You should be able to do this with fseek and fread .

$byteOffset = 1024;
$readLength = 256;
$fileHandle = fopen('myfile', 'r');
fseek($fileHandle, $byteOffset);
$bytes = fread($fileHandle, $readLength);

String to byte/binary arrays in PHP

I think you are asking for the equivalent to the Perl pack/unpack functions. If that is the case, I suggest you look at the PHP pack/unpack functions:

How can I convert array of bytes to a string in PHP?

If by array of bytes you mean:

$bytes = array(255, 0, 55, 42, 17, );

array_map()

$string = implode(array_map("chr", $bytes));

foreach()

Which is the compact version of:

$string = "";
foreach ($bytes as $chr) $string .= chr($chr);
>
// Might be a bit speedier due to not constructing a temporary array.

pack()

But the most advisable alternative could be to use pack(«C*», [$array. ]) , even though it requires a funky array workaround in PHP to pass the integer list:

$str = call_user_func_array("pack", array_merge(array("C*"), $bytes)));

That construct is also more useful if you might need to switch from bytes C* (for ASCII strings) to words S* (for UCS2) or even have a list of 32bit integers L* (e.g. a UCS4 Unicode string).

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PHP strlen

Summary: in this tutorial, you’ll learn how to use the PHP strlen() function to get the length of a string.

Introduction to the PHP strlen() function

The strlen() function returns the length of a specified string. Here’s the syntax of the strlen() function:

strlen ( string $string ) : intCode language: PHP (php)

The strlen() function has one parameter $string , which is the string to measure the length. The strlen() function returns the length of the $string in bytes or zero if the $string is empty.

It’s important to note that the strlen() function returns the number of bytes rather than the number of characters. If each character is 1 byte, the number of bytes is the same as the number of characters.

However, if you deal with the multibyte string, e.g., UTF-8, the number of bytes is higher than the number of characters.

To get the number of characters in a multibyte string, you should use the mb_strlen() function instead:

mb_strlen ( string $string , string|null $encoding = null ) : intCode language: PHP (php)

The mb_strlen() function has an additional $encoding that specifies the character encoding of the $string .

The mb_strlen() function returns the number of characters in the $string having character $encoding . The mb_strlen() returns one for each multibyte character.

PHP strlen() function examples

Let’s take some examples of using the strlen() function.

1) Simple strlen() function example

The following example uses the strlen() function to return the length of the string PHP:

 $str = 'PHP'; echo strlen($str); // 3Code language: PHP (php)

2) Using the strlen() with a multibyte string

The following multibyte string has five characters. However, its size is 15 bytes.

'こんにちは'Code language: PHP (php)

By the way, こんにちは is a greeting in Japanese. It means hello in English.

The strlen() function returns 15 bytes for the string ‘こんにちは’ :

 $message = 'こんにちは'; echo strlen($message); // 15 bytes Code language: PHP (php)

But the mb_strlen() function returns five characters for that string:

 $message = 'こんにちは'; echo mb_strlen($message); // 5 charactersCode language: PHP (php)

Summary

• Use the PHP strlen() function to get the number of bytes of a string.
• Use the PHP mb_strlen() function to get the number of characters in a string with a specific encoding.

Источник

Work Out Size In Bytes Of A PHP String

Note: This post is over two years old and so the information contained here might be out of date. If you do spot something please leave a comment and we will endeavour to correct.

I found this very handy function on the php.net site in the user comments for the strlen() function. It accepts a string in ASCII or UTF-8 format and finds out how long that string is in bytes.

The function works by going through the string and adding how many bytes each character represents. For normal ASCII values this is a single byte so 1 is added to the total. Unicode characters can be up to 6 bytes and so the rest of this function works out how many bytes the character takes up by using AND calculations.

); switch(true)< case(($ord_var_c >= 0x20) && ($ord_var_c ; >; return $d; >

This string is useful if you want to know how large a string is in bytes, but have only a small amount of control over how the string will be presented. For example, if you download a web page and want to know how large it is in bytes you can pass the content of the page into this function.

You might think that the Content-Length header could be used here, but you can’t rely on this header to be returned from every site. Some sites will simply omit the line, whilst others will just put a default amount there.

Phil is the founder and administrator of #! code and is an IT professional working in the North West of the UK. Graduating in 2003 from Aberystwyth University with an MSc in Computer Science Phil has previously worked as a database administrator, on an IT help desk, systems trainer, web architect, usability consultant, blogger and SEO specialist. Phil has lots of experience building and maintaining PHP websites as well as working with associated technologies like JavaScript, HTML, CSS, XML, Flex, Apache, MySQL and Linux.

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Comments

It returned the string lenght not the size in byte.

Submitted by Anonymous on Sat, 04/07/2012 — 22:00

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