PHP view special characters in a string

Question

Trying to figure out, what PHP is doing with newlines and special characters. I have a string, when I do var_dump($string) the output is:

string 'ls -al

    free -m' (length=16)

How do I view the special characters buried in here? For example need to see if they are \n or&#10 or whatever they are.

Thanks.

score 6 · Answer 1 · answered Sep 12 '12 at 06:27

6

The best way to see unprintable characters is by printing bin2hex($string). This gives you an actual binary dump of the string. Compare this with your favorite ASCII table or other table specific to the encoding your string is in.

answered Sep 12 '12 at 06:27

deceze

510,633
85
743
889

Ok, so the output of the hex is `6c73202d616c0d0a66726565202d6d` which using a converter from hex to ascii outputs `ls -al??free -m` notice the ??. Those should be \n. Any idea what the heck is going on? – Justin Sep 12 '12 at 07:03
1

The hex dump looks pretty normal. The `0d0a` in the middle is simply a CRLF Windows linefeed. – deceze Sep 12 '12 at 07:39

Alain Tiemblo · Answer 2 · 2012-09-12T06:33:41.097

If you're running your command in an unix environnement with PHP Cli, you may try using cat.

php file.php | cat -e

Else, you can handle var_dump into a string and display manually special chars :

$string = "test
test";

$dump = var_export($string, true);
for ($i = 0; ($i < strlen($dump)); $i++) {
    if ((ord($dump[$i]) < 32) || (ord($dump[$i]) > 127)) {
        echo '(' . ord($dump[$i]) . ')';
    } else {
        echo $dump[$i];
    }
}

// will output 'test(13)(10)test' on Windows, 'test(10)test' on Unix systems.

score 0 · Answer 3 · answered Sep 12 '12 at 06:47

0

You could use:

preg_match("/(&#[0-9]+;)|[\t\r\n]/", $string, $matches);
print_r($matches);

answered Sep 12 '12 at 06:47

dotoree

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PHP view special characters in a string

3 Answers3