Negative testing with mktime()

HeidiR

I'm doing some negative testing with mktime() to try to get mktime() to return FALSE. However, it appears that any values I send mktime, including special character, do not produce an error (FALSE return). What am I missing???

dagon

dont know why you want to but:

$test=mktime(1, 2, 3, 4, 5, 201111111);
var_dump($test); //bool(false)

bradgrafelman

What did you try? If I pass a string to any of mktime()'s arguments, I get boolean FALSE as expected.

HeidiR

That's odd. I ran your same code by it self in a test script and got: int(63402374185323). What's with that?

dagon

what php version are you running? "63402374185323" is not a valid unixtime

bradgrafelman

dagon;10970997 wrote:
what php version are you running? "63402374185323" is not a valid unixtime

Why wouldn't that be a valid Unix timestamp?

HeidiR

dagon;10970997 wrote:
what php version are you running? "63402374185323" is not a valid unixtime

php version is 5.2.15.

Running the following code produces: int(63402374185323)

$test=mktime(1, 2, 3, 4, 5, 201111111);
var_dump($test);

dagon

bradgrafelman;10971001 wrote:
Why wouldn't that be a valid Unix timestamp?

being lazy i dropped it in to the first online converter i found and it said it was invalid, other's however don't - my bad.

dagon

HeidiR;10971002 wrote:
php version is 5.2.15.

Running the following code produces: int(63402374185323)

$test=mktime(1, 2, 3, 4, 5, 201111111);
var_dump($test);

i don't have that php version, i see no bug report for mktime that can explain this. you are running this on a page with nothing else?

bradgrafelman

Well I can see why some would call it invalid; that integer obviously exceeds the 32-bit boundary (2^31-1) for an int32 number, but it sounds like HeidiR's PHP binary was compiled against 64-bit libraries instead.

@: If the above answer makes sense, and you still want proof that mktime() does indeed behave as expected, try this instead:

$test=mktime(0, 0, 0, 12, 5, 292277026596); 
var_dump($test);

That should return boolean FALSE on a 64-bit machine, while this:

$test=mktime(0, 0, 0, 12, 3, 292277026596); 
var_dump($test);

should not.

dagon

your too good at this bradgrafelman, im going to stop trying to answer questions and mow the lawn.

HeidiR

bradgrafelman;10971005 wrote:
Well I can see why some would call it invalid; that integer obviously exceeds the 32-bit boundary (2^31-1) for an int32 number, but it sounds like HeidiR's PHP binary was compiled against 64-bit libraries instead.

@: If the above answer makes sense, and you still want proof that mktime() does indeed behave as expected, try this instead:
$test=mktime(0, 0, 0, 12, 5, 292277026596); 
var_dump($test);
That should return boolean FALSE on a 64-bit machine, while this:
$test=mktime(0, 0, 0, 12, 3, 292277026596); 
$test=mktime(0, 0, 0, 12, 5, 292277026596); 
var_dump($test);
should not.

That for the info guys!

I tried the following two line of code, which returned: int(9223372036854655200)

$test=mktime(0, 0, 0, 12, 5, 292277026596); 
var_dump($test);

Also as a note, I noticed that mktime() returns a float.

bradgrafelman

Crap, that's still within the range of 2^63-1... my bad. Try increasing the year by one - that should give you FALSE.

HeidiR wrote:
Also as a note, I noticed that mktime() returns a float.

Er... no, it doesn't. The letters "int" in both the PHP manual as well as your var_dump() output you posted above stand for integer, not float.

HeidiR

Thanks for the info. Changing the code to:

mktime(0,0,0,12,3,292277026598);

Returned:

int(-9223372036791824416)

HeidiR

It's odd that mktime() seems to only do minimal error checking of parms. After some additional testing, if found the following results:

$t=mktime(0,0,0,12,3,292277026596);
var_dump($t);

$t=mktime(0,0,0,12,3,292277026597);
var_dump($t);

$t=mktime(900000000000,900000000000,900000000000,900000000000,900000000000,900000000000);
var_dump($t);

int(9223372036854655200)
int(-9223372036823360416)
int(-6044405109589065632)

It appears that once the parm value exceeds the value limit of a long var, the function returns a negative value. No warnings are produced. Instead of returning FALSE for an error, the function just returns an invalid result.

bradgrafelman

On a 32-bit version of PHP, the function does return boolean false for values that are out-of-range instead of wrapping around.

I think this is probably a bug in the 64-bit version of PHP, however since php.net doesn't really seem to care about 64-bit all that much yet, I'm not sure how much effort they'd invest towards looking into this.

Still, you should take all of the info we've discovered in this thread and report what you've found as a bug to the developers and post back here with the bug id# so we can see what they have to say about it.

HeidiR

Reported PHP Bug #53608 - mktime() produces invalid results under 64-bit