error-logging – Make Me Engineer

Print PHP Call Stack

November 6, 2022 by Tarik

More readable than debug_backtrace(): $e = new \Exception; var_dump($e->getTraceAsString()); #2 /usr/share/php/PHPUnit/Framework/TestCase.php(626): SeriesHelperTest->setUp() #3 /usr/share/php/PHPUnit/Framework/TestResult.php(666): PHPUnit_Framework_TestCase->runBare() #4 /usr/share/php/PHPUnit/Framework/TestCase.php(576): PHPUnit_Framework_TestResult->run(Object(SeriesHelperTest)) #5 /usr/share/php/PHPUnit/Framework/TestSuite.php(757): PHPUnit_Framework_TestCase->run(Object(PHPUnit_Framework_TestResult)) #6 /usr/share/php/PHPUnit/Framework/TestSuite.php(733): PHPUnit_Framework_TestSuite->runTest(Object(SeriesHelperTest), Object(PHPUnit_Framework_TestResult)) #7 /usr/share/php/PHPUnit/TextUI/TestRunner.php(305): PHPUnit_Framework_TestSuite->run(Object(PHPUnit_Framework_TestResult), false, Array, Array, false) #8 /usr/share/php/PHPUnit/TextUI/Command.php(188): PHPUnit_TextUI_TestRunner->doRun(Object(PHPUnit_Framework_TestSuite), Array) #9 /usr/share/php/PHPUnit/TextUI/Command.php(129): PHPUnit_TextUI_Command->run(Array, true) #10 /usr/bin/phpunit(53): PHPUnit_TextUI_Command::main() #11 {main}”

Internal Error 500 Apache, but nothing in the logs?

October 8, 2022 by Tarik

Why are the 500 Internal Server Errors not being logged into your apache error logs? The errors that cause your 500 Internal Server Error are coming from a PHP module. By default, PHP does NOT log these errors. Reason being you want web requests go as fast as physically possible and it’s a security hazard … Read more

How do you log server errors on django sites

July 18, 2022 by Tarik

Well, when DEBUG = False, Django will automatically mail a full traceback of any error to each person listed in the ADMINS setting, which gets you notifications pretty much for free. If you’d like more fine-grained control, you can write and add to your settings a middleware class which defines a method named process_exception(), which … Read more

How to use ELMAH to manually log errors

July 13, 2022 by Tarik

Direct log writing method, working since ELMAH 1.0: try { some code } catch(Exception ex) { Elmah.ErrorLog.GetDefault(HttpContext.Current).Log(new Elmah.Error(ex)); } ELMAH 1.2 introduces a more flexible API: try { some code } catch(Exception ex) { Elmah.ErrorSignal.FromCurrentContext().Raise(ex); } There is a difference between the two solutions: Raise method applies ELMAH filtering rules to the exception. Log method … Read more

“[notice] child pid XXXX exit signal Segmentation fault (11)” in apache error.log [closed]

June 25, 2022 by Tarik

Attach gdb to one of the httpd child processes and reload or continue working and wait for a crash and then look at the backtrace. Do something like this: $ ps -ef|grep httpd 0 681 1 0 10:38pm ?? 0:00.45 /Applications/MAMP/Library/bin/httpd -k start 501 690 681 0 10:38pm ?? 0:00.02 /Applications/MAMP/Library/bin/httpd -k start … Now … Read more

Making Python loggers output all messages to stdout in addition to log file

June 10, 2022 by Tarik

All logging output is handled by the handlers; just add a logging.StreamHandler() to the root logger. Here’s an example configuring a stream handler (using stdout instead of the default stderr) and adding it to the root logger: import logging import sys root = logging.getLogger() root.setLevel(logging.DEBUG) handler = logging.StreamHandler(sys.stdout) handler.setLevel(logging.DEBUG) formatter = logging.Formatter(‘%(asctime)s – %(name)s – … Read more

Error handling in Bash [closed]

May 16, 2022 by Tarik

Use a trap! tempfiles=( ) cleanup() { rm -f “${tempfiles[@]}” } trap cleanup 0 error() { local parent_lineno=”$1″ local message=”$2″ local code=”${3:-1}” if [[ -n “$message” ]] ; then echo “Error on or near line ${parent_lineno}: ${message}; exiting with status ${code}” else echo “Error on or near line ${parent_lineno}; exiting with status ${code}” fi exit … Read more