[PHP] Error recovery - fatal errors
I would like, in my app, to recover from as many run-time errors as possible, so that I can tidy up. And unsolicited output generated by the standard error system is really unhelpful as it becomes part of the ajax reply to the browser. So I've added my own error handler, but it seems that I can't catch fatal errors. The error in question comes from doing something like: $res = $dbh-query ($sql); with $sql being an SQL statement, and $dbh being a database handle. I recently had a case where $dbh was NULL, which triggers a fatal error from SQLite. In principle such a bug should show up quickly, but this one had lain untriggered for about a year. It seems to me somewhat arbitrary for this to be designated a fatal error. Is there a way I can catch these? Most SQLite error situations I'm solving with try/catch but no luck with this one so far. Error handling in library packages seems somewhat arbitrary - e.g. opendir may give an E_WARNING, but closedir, readdir don't. tim -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] mysql problems [SOLVED]
Sean Greenslade wrote:
[MASSIVE
SNIP]
Well, from what I saw while wading through your
code, you allow
unsanitized
variables to be
concatenated to your queries. Big no-no! For ANY
client-generated variable, always sanitize with
mysql_real_escape_string.
In
fact, sanitize all your
variables. It can't hurt.
Also, please don't take a
request for your entire code too literally. We
don't like to see
pages and pages and pages of code, just the pertinent
bits.
--
--Zootboy
Sent from my PC.
Thanks to all, but it was an infinite loop. there was a
while ($_parent != 0) { } loop. In the loop the database
is queried. If the returned number of rows is greater than 0 then
perform then grab a $_parent from the database. At some point, there
must be a parent that is = 0 and the loop breaks. However, if the
page is called with category number that doesn't exist, then the if/then
clause is never true and $_parent never gets set to 0. I simply
added and else clause.
while ($_parent != 0)
{
if
($num_rows 0)
{
perform some action
}
else
{
$_parent =
0;
}
}
and that solved the
problem.
Thank you, everyone for your help.
Curtis
RE: [PHP] mysql problems [SOLVED]
[SNIP]
added and else clause.
while ($_parent != 0)
{
if
($num_rows 0)
{
perform some action
}
else
{
$_parent =
0;
}
}
and that solved the
problem.
Thank you, everyone for your help.
Curtis
A small remark:
I think it is good programming practice to place such static if-clauses before
the while statement.
This prevents a lot of redundant checks and thus saves time.
Best regards,
Jasper
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Re: [PHP] Error recovery - fatal errors
On 14 May 2011 12:33, Tim Streater t...@clothears.org.uk wrote: I would like, in my app, to recover from as many run-time errors as possible, so that I can tidy up. And unsolicited output generated by the standard error system is really unhelpful as it becomes part of the ajax reply to the browser. So I've added my own error handler, but it seems that I can't catch fatal errors. The error in question comes from doing something like: Fatal errors are fatal - if you could recover from them, they wouldn't be fatal. $res = $dbh-query ($sql); with $sql being an SQL statement, and $dbh being a database handle. I recently had a case where $dbh was NULL, which triggers a fatal error from SQLite. In principle such a bug should show up quickly, but this one had lain untriggered for about a year. It seems to me somewhat arbitrary for this to be designated a fatal error. Is there a way I can catch these? Most SQLite error situations I'm solving with try/catch but no luck with this one so far. You've got something wrong: either $dbh is not null or the error is not from sqlite. I'm guessing the former. To avoid situations like that, do proper error checking (i.e. actually check that your database connection was opened succesfully). Error handling in library packages seems somewhat arbitrary - e.g. opendir may give an E_WARNING, but closedir, readdir don't. You can avoid all problems with error output by turning off error displays in php.ini (set display_errors = off) - use error logging instead. That's the recommended setting for production servers. Regards Peter -- hype WWW: plphp.dk / plind.dk LinkedIn: plind BeWelcome/Couchsurfing: Fake51 Twitter: kafe15 /hype -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
