PHP - Add null character to string

Question

I'm trying to append a number of NULL characters '\0' to a string in PHP.

$s = 'hello';
while(strlen($s) < 32) $s .= '\0';

However, PHP adds 2 characters (\ and 0), instead of escaping the character and adding NULL. Does anyone know to add a NULL character to a string?

Nope, adding null does not increase the string length. Hence, the loop is infinite. — goocreations, Jul 30 '15 at 08:35

score 9 · Accepted Answer · answered Jul 30 '15 at 08:36

9

I don't know if \0 is correct in your case, but you should use ":

$s = 'hello';
while(strlen($s) < 32) $s .= "\0";

answered Jul 30 '15 at 08:36

t.h3ads

well, well, well. That worked. I thought ' and " are synonyms in PHP? – goocreations Jul 30 '15 at 08:37
2

Here is some further explanation: http://stackoverflow.com/questions/1318028/php-different-quotes – t.h3ads Jul 30 '15 at 08:38
Thanks. Learned something new. – goocreations Jul 30 '15 at 08:40

score 3 · Answer 2 · answered Jul 30 '15 at 08:42

3

Caused by ' you should use ".

Using simple quote PHP doesn't interpret code or special char like (\n\r\0), by using double quote PHP will.

answered Jul 30 '15 at 08:42

Disfigure

score 2 · Answer 3 · answered May 09 '16 at 20:43

2

This appears to work:

$result = str_pad($str, 32, "\0");
echo strlen($result); // output: 32

answered May 09 '16 at 20:43

Tim McKinney

score 0 · Answer 4 · answered Jul 30 '15 at 09:20

0

Try the following code

echo $str="Hello "; echo ' Length : '.strlen($str); while(strlen($str)<32) { $str.=' '; } echo '<br/>'; echo $str; echo ' Length : '.strlen($str);

Hope this will solve your problem

answered Jul 30 '15 at 09:20

karvin.developer

score 0 · Answer 5 · answered May 09 '20 at 01:40

0

Just the following line is enough:

$s = pack('a32', 'hello');

answered May 09 '20 at 01:40

mnrafg

5 Answers5