track_vars and $GLOBALS

MrAlaska

Hiya. I tried to post this question to the PHP developers newsgroup a few hours ago, but it is not showing up there so maybe my email is in cyberspace somewhere. While I was waiting for it to show up, I thought I might see if anybody here has any ideas.

It appears there is no setting to disable track_vars since version 4.0.3? Would it not be a potential performance benifit to disable tracking? Does this indicate a possible future move to abandon the $GLOBALS array and only track the arrays it now contains?

For backward compatibity I am currently writing my functions to only access the global variables through the $GLOBALS array. Is this a dangerous practice considering future code compatibility?

Bunkermaster

default param is on but it can be changed in php.ini... i think

philipolson

track_vars is dead, using autoglobals is the preferred method. Don't use $GLOBALS as this means you're relying on register_globals = on, a directive that now defaults to off (as of PHP 4.2.0).

There is talk of killing register_globals, in fact, some people consider it deprecated. For future code compatibilty, use the predefined autoglobal arrays instead.

Another option is import_request_variables().

MrAlaska

Originally posted by philipolson
track_vars is dead, using autoglobals is the preferred method. Don't use $GLOBALS as this means you're relying on register_globals = on, a directive that now defaults to off (as of PHP 4.2.0).

There is talk of killing register_globals, in fact, some people consider it deprecated. For future code compatibilty, use the predefined autoglobal arrays instead.

Another option is import_request_variables().

Killing register_globals would not bother me in the slightest, I am a proponent of declaring variables explicitly anyway for code flow purposes, not even mentioning the security issues.

The $GLOBALS array holds all the predefined variables at this point and does NOT depend on register_globals being on. As a matter of fact, if register_globals is off AND track_vars is off, I believe the $GLOBALS array is the only means of accessing any of the predifined variables. At any rate, it works fine for me at this time and I have register_globals turned OFF and error_reporting set to E_ALL.

track_vars registers the predefined variable arrays much like register_globals registers the variables themselves. Much like register_globals, it seems to have been provided for convenience. I am kind of surprised it is not in php.ini anymore and was wondering why.

philipolson

The reason is so a php script that uses predefined php variables (or autoglobals) will work regardless of php.ini settings. So, if someone uses $HTTP_GET_VARS it will work in PHP 9 nomatter what. Or $_GET for that matter. $HTTP_GET_VARS is now deprecated but most php developers feel they will be around forever.

I misread your post, and thought you wanted to get index.php?foo=bar as $GLOBALS['foo'] when of course that's not what you meant. Now noticing your number of posts ... it was a silly assumption on my part.

MrAlaska

That certainly makes sense for turning them on by default, but I would be happier to see the setting still available but accompanied with a warning not to use it l It seems to me one might realize at least a slight performance boost by disabling track_vars but it is an open source project so I suppose I could go in an 'fix' it if it meant that much to me.

Thank you.

The number of posts don't mean much. I am actually pretty new to programming and PHP. I just seem to be verbose online, even though I never have mastered making myself understood 😃