php base64_decode strange output

Question

I have a very strange output from base64_decode function. The output is a string with length of 18, however when I var_dump the string .. the length is 32! This affects the preg_match function that I'm applying for this string. Any idea why?

$input_line = base64_decode('OQA3ADgAMAA5ADgAMgA3ADQAMwA2ADAANwA5ADAAMAAwADAA');
var_dump($input_line);

Output

string(36) "978098274360790000"

Regards

There's probably unprintable characters in there, e.g. nuls. if you iterate over each character of $input_line and print out the ascii value of each char, you'll find where they're hiding.. probably at the end of the string. — Marc B
– Marc B, Commented Oct 15, 2013 at 20:47
If you force a datatype then does vardump still produce the same result? var_dump($input_line(int)); — MonkeyZeus
– MonkeyZeus, Commented Oct 15, 2013 at 20:47

user142162 · Accepted Answer · 2013-10-15 20:47:59Z

4

The string has a lot of non-printable characters (the NUL byte). You can see this by piping the value through a program like xxd:

0000000: 3900 3700 3800 3000 3900 3800 3200 3700  9.7.8.0.9.8.2.7.
0000010: 3400 3300 3600 3000 3700 3900 3000 3000  4.3.6.0.7.9.0.0.
0000020: 3000 3000                                0.0.

answered Oct 15, 2013 at 20:47

user142162

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Community · Accepted Answer · 2017-05-23 10:25:45Z

1

Thank you everyone especially @tim-cooper There are null bytes in the string and I found the solution here: How can I remove the NULL character from string

so basically:

str_replace("\0", "", $input_line);

edited May 23, 2017 at 10:25

CommunityBot

11 silver badge

answered Oct 15, 2013 at 20:53

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