timing out users

celibate54

if upon user login i grab the timestamp would there be a way to time him out?

is the only way to use session expirations? also, anybody have an example of this?

If i have a time, how can i 'add/subtract' the time stamped with the current time to determine the difference in time?

i want to have a function run every 25 minutes and i need to figure out a way to find the difference in time

thanks!

onion2k

You don't need to actually time them out by expiring the session.

Just put the timestamp of when they were last active into the session, the when they come back check the difference between the timestamp in their session and the timestamp of now, and if the difference is greater than 25minutes*60seconds kick the user out to a DENIED page.

So you'd have something along the lines of:

if ($_SESSION['timestamp'] != 0) {
if ((mktime() - $_SESSION['timestamp']) > (25*60)) {
  //bye bye mister user
  header("Location: logout.php");
  exit;
} else {
  $_SESSION['timestamp'] = mktime();
}
} else {
  $_SESSION['timestamp'] = mktime();
}

EDIT: realised it wouldn't work first time round when $_SESSION['timestamp'] would be blank..

celibate54

so would i make this into a function and call the function at the bottom of every page?

also, what if he never clicks anything in the page and just closes explorer? then he would still be accounted for as 'on'

not a big deal, but i plan on having a max user limit set.

onion2k

You'd need to call it at the top of every page as its adding a header(), but yeah.

celibate54

eep why would i call it as the header ? and i edited my message above to include another question

thanks for the fast response btw
=))

also what if i need an ABSOLUTE maximum time allowed on?
so if they logged in at noon the MAX they can be on is until 2pm?

onion2k

If the user closes the browser then their session will end anyway, so thats not a worry.

If you need to set an absolute maximum, just work out the timestamp of the maximum allowed time, store that in the session, and if the next page is accessed after that time kick the user out to the logout.php page.

And you have to call all these things in the top of the script because otherwise the header() command doesn't work. It only redirects the user if nothing else has been sent to their browser.

celibate54

if i have this set as a function and i call the function at the top

wouldn't loading the page itself initiate the function call?

i'm still quite confused with how time works. I can't figure out how to add/subtract time still

onion2k

Yeah, you could make it a function and have the function call at the top of each page. Thats fine.

Time is easiest (in my opinion) if you work with timestamps. A timestamp is the number of seconds since 1970.

So if the timestamp now is 1083793879, then the timestamp a minute ago might be 1083793879-60, and in a minutes time it'll be 1083793879+60. Using the mktime() function you can calculate the time for any second since 1970. If you want to know the time in 2 hours you just call:

mktime()+(26060);

2hours 60minutes 60seconds.

If you want 3 weeks from now:

mktime()+(86400 7 3);

86400(seconds in a day) 7 days 3 weeks.

To work out the timestamp for my birthday:

mktime(0,0,0,3,28,1977);

To work out how old I am in weeks:

(mktime() - mktime(0,0,0,3,28,1977))/(606024*7);

1414.4 weeks old. Crumbs. I'm ancient.

celibate54

so you strongly believe that calculating time differences is the easiest way? it makes the database look so ugly though because you will see 10101091919191 in one column instead of May 5th, 2004 3:39pm (or 15:39)

Originally posted by onion2k
Yeah, you could make it a function and have the function call at the top of each page. Thats fine.

Time is easiest (in my opinion) if you work with timestamps. A timestamp is the number of seconds since 1970.

So if the timestamp now is 1083793879, then the timestamp a minute ago might be 1083793879-60, and in a minutes time it'll be 1083793879+60. Using the mktime() function you can calculate the time for any second since 1970. If you want to know the time in 2 hours you just call:

mktime()+(26060);

2hours 60minutes 60seconds.

If you want 3 weeks from now:

mktime()+(86400 7 3);

86400(seconds in a day) 7 days 3 weeks.

To work out the timestamp for my birthday:

mktime(0,0,0,3,28,1977);

To work out how old I am in weeks:

(mktime() - mktime(0,0,0,3,28,1977))/(606024*7);

1414.4 weeks old. Crumbs. I'm ancient.

:p

onion2k

To store the date/time in the database as a real date just use:

$sql = "insert into table (date) values ('".date("Y-m-d h:i:s",$timestamp)."')";

To get it back out again in lovely timestamp format:

$sql = "select UNIX_TIMESTAMP(date) as unix_date from table";

Simple.

celibate54

you've really been a great help, thanks =)

celibate54

right now i have
$registerDate = date("Y-m-d h:i:s", $timestamp);

when i insert it into the db it stores as
"1969-12-31 04:00:00"

that's obviously blatantly incorrect

am i not formatting it properly?

marky2coats

That looks fine to me. Looks like your timestamp may actualy be that value?

Mark.