what throws warnings please?

zmola

i've been trying to figure out what php functions can throw warnings and which don't.

for example, session_destroy(); will throw a warning if there is no session to destroy so use @session_destroy; to supress.

will trim($foobar); throw a warning when there is no whitespace to trim? i tried an example and it didn't. does that mean it will never throw a warning saying there is no space to trim?

how about stripslashes($foobar); when there are no slashes, magic_quotes, to strip? will this throw a warning if there are no slashes in the first place? i tried an example of this but my host has magic_quotes on so i'd really like to get an answer on this last paragraph.

super thanks!!!

the_Igel

Basically, function generates a warning in case it is given illegal data or parameters. For example, session_destroy dislikes when no session is available. On the other side, any string is correct data for trim, whether it has whitespaces on the ends or not.
Warning doesn't mean a function didn't perform an action; it means that function is unable to do anything it's supposed.

Hope it helps.

zmola

stripslashes works like trim then and doesn't throw warnings?

sorry if this seems like a silly question, but of all the stuff i read about when to strip, add, blah, foo, stripslashes scares me ;-)

the_Igel

Yes, stipslashes() shouldn't generate warnings.

And why do you care that much about warnings? You can turn them off using error_reporting() anyway.

Weedpacket

The manual usually says if a given function could throw a warning, and in which situations.

Why should trim() or stripslashes() throw warnings if there is no whitespace to trim or if there are no slashes to strip? Having those do nothing in such cases is perfectly consistent with their normal behaviour - who needs a warning from a function saying that it's done something normal?

zmola

the manual didn't mention that session_destroy would throw a warning if no session. i thought that if there wasn't a session to destroy, then session_destroy would know. however, it throws a warning. so... this got me thinking that maybe other functions that i initially thought wouldn't throw a warning actually would. i was trying to figure out why some functions do and some don't throw warnings is all. yours are probably rhetorical questions, but i figured i'd explain. :-) :-) :-)

now i'm off to trying to figure out this addslashes, stripslashes stuff. this is what i have so far:

php adds slashes to get, post, cookie, and db queries when magic_quotes is on so no need to do addslashes. when magic_quotes is on, do i need to stripslashes when presenting query results to the browser? i read a previous post on here and thought it said that i did, but i do have magic_quotes on and i do not stripslashes and things look right ::cornfuzeled::

the_Igel

If they do look right, why do you want to stipslash? Never try to fix a program that works 🙂