php return 500 error but no error log_问答_开发者

I am having an issue when I have a php application that is returning an internal server error (500) however nothing is showing up in the error log.

Now I know there are error with what I am trying to run, I know I have missing some files and what not but something should show in the apache error log (otherwise how are I supposed to know exactly what I am missing).

I created a test script is errors it in under the same vhost configuration and those error show up fine so everything seems configured right as far as php/apache. Are there certain php errors that does show up in the error log (php is configure to display any type of notice, warning, , error, fatal error, etc...)?

This is running on ubunut 10.04 with the standard apache and php 开发者_如何学Gofrom the ubuntu repo with apt-get.

Scan your source files to find @.

From php documentation site

Currently the "@" error-control operator prefix will even disable error reporting for critical errors that will terminate script execution. Among other things, this means that if you use "@" to suppress errors from a certain function and either it isn't available or has been mistyped, the script will die right there with no indication as to why.

Copy and paste the following into a new .htaccess file and place it on your website's root folder :

php_flag  display_errors                  on
php_flag  display_startup_errors          on

Errors will be shown directly in your page.

That's the best way to debug quickly but don't use it for long time because it could be a security breach.

If you still have 500 error and no logs you can try to execute from command line:

php -f file.php

it will not work exactly like in a browser (from server) but if there is syntax error in your code, you will see error message in console.

Maybe something turns off error output. (I understand that you are trying to say that other scripts properly output their errors to the errorlog?)

You could start debugging the script by determining where it exits the script (start by adding a echo 1; exit; to the first line of the script and checking whether the browser outputs 1 and then move that line down).

In the past, I had no error logs in two cases:

The user under which Apache was running had no permissions to modify php_error_log file.
Error 500 occurred because of bad configuration of .htaccess, for example wrong rewrite module settings. In this situation errors are logged to Apache error_log file.

For Symfony projects, be sure to check files in the project'es app/logs

More details available on this post :
How to debug 500 Error in Symfony 2

Btw, other frameworks or CMS share this kind of behaviour.

Here is another reason why errors might not be visible:

I had the same issue. In my case, I had copied the source from a production environment. Hence the ENVIRONMENT variable defined in index.php was set to 'production'. This caused error_reporting to be set to 0 (no logging). Just set it to 'development' and you should start seeing error messages in apache log.

Turned out the 500 was due to a semi colon missing in database config :-)

Another case which happened to me, is I did a CURL to some of my pages, and got internal server error and nothing was in the apache logs, even when I enabled all error reporting.

My problem was that in the CURL I set curl_setopt($CR, CURLOPT_FAILONERROR, true);

Which then didn't show me my error, though there was one, this happened because the error was on a framework level and not a PHP one, so it didn't appear in the logs.

You need to enable the PHP error log.

This is due to some random glitch in the web server when you have a php error, it throws a 500 internal error (i have the same issue).

If you look in the PHP error log, you should find your solution.

see here in the doc of how to enable it in the php.ini

Be sure your file permissions are correct. If apache doesn't have permission to read the file then it can't write to the log.

What happened for me when this was an issue, was that the site had used too much memory, so I'm guessing that it couldn't write to an error log or displayed the error. For clarity, it was a Wordpress site that did this. Upping the memory limit on the server showed the site again.

SOLVED I struggled with this and later on, I realized that I was working on PHP 5.6, so I upgraded to PHP 7.0, then I released there were comments placed by git for conflicting codes. I found something like this in my code <<<<<<<< But solved it.

If you

Are getting an intermittent Error 500 when submitting forms, and
You can't get a PHP error message to display even with display_errors(-1)

Then the problem may be

Your web hosting company may have a ModSecurity plugin installed, that checks $_POST for certain regex matches

You can verify this by

Going to /home/youraccount/log/.../.../error.log, which should have the detailed error logs that you can't see in browser

The fix is

Go into your web hosting control panel, find a setting that says "Extra Web Security?" or similar, and turn it off for that domain. You should be able to google for info specific to your web hosting company.