Re^3: error messages without program names or line numbers

Both excellent points, ++ to both of you, but the bigger problem (as I admittedly should have elaborated on) is how to catch errors I don't have dominion over?

For instance, a database error with RaiseError turned on will display a whole mess of crap.

of course, i think compile-time and/or syntax errors may occur before CGI::Carp can catch them, but I'm more concerned with outside forces, such as assorted modules.

__________
Build a man a fire, and he'll be warm for a day. Set a man on fire, and he'll be warm for the rest of his life.
- Terry Pratchett

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Re^4: error messages without program names or line numbers by jhourcle (Prior) on Aug 04, 2006 at 17:21 UTC
Odds are, if you pass errors from modules you didn't write, you're leaking information to the user that they either won't understand, or they will understand, and can potentially use to exploit the system. I'd recommend trapping all errors, and sending them to the error log, but sending a generic message to the user. (hopefully something more than 'something went wrong ... contact the system administrator'). You might trap and leave a different generic message in different sections of your code. Depending on what the site's doing (and how locked down it is in the first place), I might hide a more useful error code/message in the source, but typically, the error page is a feedback form to alert the sysadmin -- they can leave contact information if they wish, but I can also poll for HTTP_USER_AGENT and the like, and ask them what they were doing at the time it gave them problems. And I think it goes without saying -- if you're likely to error out due to database connections, don't track this in the database, and if you're likely to error out from writing files, don't write it to a log file w/out some other form of backup. Mail is usually good, so long as the partition w/ the mqueue doesn't fill up. (and you watch it to make sure mail's actually flowing)	[reply]
Re^4: error messages without program names or line numbers by cdarke (Prior) on Aug 04, 2006 at 20:08 UTC
In that case you can wrap an eval {...} block around calls to suspect external subs (or anywhere else). Error messages will be passed into $@ ($EVAL_ERROR) and you can do with them what you like. Either test for undef returned by eval, or $@ for a non-empty string, both of which indicate an error has occured.	[reply]