[nycphp-talk] NEW PHundamentals Question - Error Handling
Jeff Siegel - PHundamentals
jeff.siegel at nyphp.org
Mon May 10 09:17:02 EDT 2004
Can you narrow this down in the context of PHP programming?
Not everything may be relevant (or maybe it is?) in the context of
building/programming a website.
Jeff
Tim Gales wrote:
> Indeed something can always go wrong.
>
> Good error handling should take a page
> out of basic journalism's playbook.
>
> when something goes wrong you want to
> know the five W's --
>
> Who, What, Where, When, and How.
>
> Roughly speaking there are three Where's:
>
> Hardware (e.g. disk full)
> OS or system (e.g. a process never gets
> environment scheduled for some reason --
> that is, it doesn't seem to
> be running for lack of a
> 'time slice')
> Software (this includes utility software
> like a compiler generating
> some sort of 'wrong stuff' and
> the developers' logic flaws in
> the application software)
>
> Basically the Who's are determine by what
> mode the code is running in. For example:
> kernel mode, user mode etc.
>
> The what's are generally governed by the
> Where's. For instance in unix-like operating
> systems events may be signaled. On a specific
> CPU the hardware may 'trap' to a vector
> interrupt when you try to divide by zero.
>
> In application software (or frameworks as well)
> there will quite likely be a list of possible
> exceptions.
>
> When's are not only the time according to
> the system clock, but also the order in
> which things have happened like a misbehaving
> routine was called just after calling some
> other routine (generally you can get this
> type of information from some sort of
> stack trace).
>
> Putting all the W's together show help
> to come up with an answer for the big 'W' --
> WHY did something go wrong?
>
> In trying to answer the big W you sometimes
> can find yourself sounding like a member on
> a congressional investigation committee.
> Saying to yourself things like:
> "What did this routine know -- and when did
> he know it".
>
>
> T. Gales & Associates
> 'Helping People Connect with Technology'
>
> http://www.tgaconnect.com
>
>
>
>>-----Original Message-----
>>From: talk-bounces at lists.nyphp.org
>>[mailto:talk-bounces at lists.nyphp.org] On Behalf Of Jeff
>>Siegel - PHundamentals
>>Sent: Monday, May 10, 2004 7:31 AM
>>To: NYPHP Talk
>>Subject: [nycphp-talk] NEW PHundamentals Question - Error Handling
>>
>>
>>"Something can always go wrong in an application so it is
>>essential that
>>your application have an error handler. What types of errors can be
>>safely ignored, and which ones should be trapped by an error handler?
>>What is the best way to handle those errors?"
>>
>>Jeff Siegel & Michael Southwell
>>The PHundamentals Team
>>
>>
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