Search results
Results from the WOW.Com Content Network
In most encodings, this is translated to a single code unit with a zero value. For instance, in UTF-8 it is a single zero byte. However, in Modified UTF-8 the null character is encoded as two bytes: 0xC0,0x80. This allows the byte with the value of zero, which is now not used for any character, to be used as a string terminator.
Null-terminated strings require that the encoding does not use a zero byte (0x00) anywhere; therefore it is not possible to store every possible ASCII or UTF-8 string. [ 8 ] [ 9 ] [ 10 ] However, it is common to store the subset of ASCII or UTF-8 – every character except NUL – in null-terminated strings.
The length of a string is the number of code units before the zero code unit. [1] The memory occupied by a string is always one more code unit than the length, as space is needed to store the zero terminator. Generally, the term string means a string where the code unit is of type char, which is exactly 8 bits on all modern machines.
For example, the null character (U+0000 NULL) is used in C-programming application environments to indicate the end of a string of characters. In this way, these programs only require a single starting memory address for a string (as opposed to a starting address and a length), since the string ends once the program reads the null character.
A numeric character reference refers to a character by its Universal Character Set/Unicode code point, and a character entity reference refers to a character by a predefined name. A numeric character reference uses the format &#nnnn; or &#xhhhh; where nnnn is the code point in decimal form, and hhhh is the code point in hexadecimal form.
However, you can encode a NULL char into a UTF8 stream with a 0xC0, 0x80 sequence, which then becomes a 0x0000 when converted to UTF16. - Richfife 16:09, 13 September 2013 (UTC) Zero is a valid code point, and the UTF-8 encoding of it is a NUL (\0) byte. An 0xC0, 0x80 sequence in a UTF-8 string is an invalid overlong encoding.
Each header consists of a name–value pair, where both the name and the value are null-terminated strings . The value can be an empty string, in which case the terminating null still remains. Neither name nor value can contain any embedded null bytes. These considerations are standard for C strings, but are often confusing for programmers used ...
Most shellcodes are written without the use of null bytes because they are intended to be injected into a target process through null-terminated strings. When a null-terminated string is copied, it will be copied up to and including the first null but subsequent bytes of the shellcode will not be processed.