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How do I get PHP errors to display?

I have checked my PHP ini file (php.ini) and display_errors is set and also error reporting is E_ALL. I have restarted my Apache webserver.

I have even put these lines at the top of my script, and it doesn't even catch simple parse errors. For example, I declare variables with a "$" and I don't close statements";". But all my scripts show a blank page on these errors, but I want to actually see the errors in my browser output.

error_reporting(E_ALL);
ini_set('display_errors', 1);

What is left to do?

I've yet to nail down exactly why this works sometimes and not others, but for anyone wanting to quickly toggle errors in a php script (or enable them via a $_REQUEST parameter) these two lines will work most of the time.
well you can see details of the error by enabling xdebug from php ini file.
Most specific editors / IDEs like e.g. Notepad++,Eclipse have builtin syntax check and highlighting, They will show you issues like you described. Please don't turn on the display of errors on a live system. Hackers will love this, because in most cases paths are shown. You can define error / exeception handler. In this handler you could log the issue and send a mail to the developer, so that he can fix it immediately when an issue occurs. see php.net/manual/en/function.set-error-handler.php and php.net/manual/en/function.set-exception-handler.php

a
anthonyryan1

This always works for me:

ini_set('display_errors', '1');
ini_set('display_startup_errors', '1');
error_reporting(E_ALL);

However, this doesn't make PHP to show parse errors - the only way to show those errors is to modify your php.ini with this line:

display_errors = on

(if you don't have access to php.ini, then putting this line in .htaccess might work too):

php_flag display_errors 1

Also note that you can use these 3 lines, and then include('fileImWorkingOn.php');. Then you can catch the syntax errors too!
While I'm no SysOps, I think more people have an .htaccess file than php.ini, and these would both come before parsing, right? php_flag display_errors 1 for .htaccess
E_ALL isn't sufficient to display all errors in PHP 5.3. "E_STRICT became part of E_ALL in 5.4.0" - PHP Manual You need E_ALL | E_STRICT or -1 in that version.
Man, I'm going to tattoo these three lines
@JuanC.Roldán I literally come back to this answer three times a week.
C
Community

You can't catch parse errors when enabling error output at runtime, because it parses the file before actually executing anything (and since it encounters an error during this, it won't execute anything). You'll need to change the actual server configuration so that display_errors is on and the approriate error_reporting level is used. If you don't have access to php.ini, you may be able to use .htaccess or similar, depending on the server.

This question may provide additional info.


j
j0k

Inside your php.ini:

display_errors = on

Then restart your web server.


+①. On my ubuntu /etc/php5/apache2/php.ini
for restart (Debian, Ubuntu, etc.) sudo service apache2 restart
For restart on OS X sudo apachectl -k restart.
fun fact: you can locate your php.ini file loaded if you simply put in phpinfo(); into a blank php file. it's the 7th row down and called Loaded Configuration File
This doesn't work for me. In fact I can call ini_get('display_errors') and it returns an empty string (meaning it is turned off). And yes I checked to make sure it is the only line in the configuration file. The setting is getting overridden somehow and I can't figure out why and it is driving me nuts. Yes, I've searched everything in /etc/php.d/ and it is not one of those files either. Yes, I restarted the web server too. No, there is nothing in the .htaccess file. I'm using PHP 7.4.6.
a
andre

To display all errors you need to:

1. Have these lines in the PHP script you're calling from the browser (typically index.php):

error_reporting(E_ALL);
ini_set('display_errors', '1');

2.(a) Make sure that this script has no syntax errors

—or—

2.(b) Set display_errors = On in your php.ini

Otherwise, it can't even run those 2 lines!

You can check for syntax errors in your script by running (at the command line):

php -l index.php

If you include the script from another PHP script then it will display syntax errors in the included script. For example:

index.php

error_reporting(E_ALL);
ini_set('display_errors', '1');

// Any syntax errors here will result in a blank screen in the browser

include 'my_script.php';

my_script.php

adjfkj // This syntax error will be displayed in the browser

All I get when doing php -l phpfilename.php is a message that says "Errors parsing sql_lab.php". It doesn't tell me what the errors are.
In addition to the blank screen it will return an Error 500 which is way more safe to measure than just no content.
P
Peter Mortensen

Some web hosting providers allow you to change PHP parameters in the .htaccess file.

You can add the following line:

php_value display_errors 1

I had the same issue as yours and this solution fixed it.


And if you are in nginx environment then add the php value to your site (sites-available) configuration under the location ~\.php directive. fastcgi_param PHP_VALUE " error_reporting=E_ALL;\n display_errors=1;";
F
Frank Forte

You might find all of the settings for "error reporting" or "display errors" do not appear to work in PHP 7. That is because error handling has changed. Try this instead:

try{
     // Your code
} 
catch(Error $e) {
    $trace = $e->getTrace();
    echo $e->getMessage().' in '.$e->getFile().' on line '.$e->getLine().' called from '.$trace[0]['file'].' on line '.$trace[0]['line'];
}

Or, to catch exceptions and errors in one go (this is not backward compatible with PHP 5):

try{
     // Your code
} 
catch(Throwable $e) {
    $trace = $e->getTrace();
    echo $e->getMessage().' in '.$e->getFile().' on line '.$e->getLine().' called from '.$trace[0]['file'].' on line '.$trace[0]['line'];
}

Do you mean PHP7 or PHP7.1 ? I am confused, I tried as the validated answer proposed and it works, I think you are proposing something a bit different IMHO, indeed "no backward compatibility" and if you have to modify a full PHP < 7 code and need to add try{} catch() {} code everywhere in your already defined php code, I don't even want to think the mess that's going to be..
@FancyJohn, this could help: $bt = debug_backtrace(); print_r($bt);.
@ballangddang, I ran into the issue with PHP 7.0, where the only way I could get the error to display was using the try/catch blocks and specifically catching Error. If you rewrite all requests (except maybe JavaScript, CSS, Images, etc) to the index.php file, then have the try catch block there, it makes it easier. Yes, any system that does not have a single entry point would be a major headache to update.
Does PHP not show unhandled exceptions? Pretty sure it does?
It should show unhandled exceptions. If you turn on an output buffer at the start (so that you can send headers at any point before finally flushing the response body) maybe the exception message can get lost somewhere.
P
Peter Mortensen

This will work:

<?php
     error_reporting(E_ALL);
     ini_set('display_errors', 1);    
?>

October 2020: This worked for me. So easy. No messing around with .htaccess or php.ini. When you're done, just comment it out or remove it. PHP 7.4
P
Peter Mortensen

Use:

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

This is the best way to write it, but a syntax error gives blank output, so use the console to check for syntax errors. The best way to debug PHP code is to use the console; run the following:

php -l phpfilename.php

P
Peter Mortensen

Set this in your index.php file:

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

P
Peter Mortensen

Create a file called php.ini in the folder where your PHP file resides.

Inside php.ini add the following code (I am giving an simple error showing code):

display_errors = on

display_startup_errors = on

P
Peter Mortensen

As we are now running PHP 7, answers given here are not correct any more. The only one still OK is the one from Frank Forte, as he talks about PHP 7.

On the other side, rather than trying to catch errors with a try/catch you can use a trick: use include.

Here three pieces of code:

File: tst1.php

<?php
    error_reporting(E_ALL);
    ini_set('display_errors', 'On');
    // Missing " and ;
    echo "Testing
?>

Running this in PHP 7 will show nothing.

Now, try this:

File: tst2.php

<?php
    error_reporting(E_ALL);
    ini_set('display_errors', 'On');
    include ("tst3.php");
?>

File: tst3.php

<?php
    // Missing " and ;
    echo "Testing
?>

Now run tst2 which sets the error reporting, and then include tst3. You will see:

Parse error: syntax error, unexpected end of file, expecting variable (T_VARIABLE) or ${ (T_DOLLAR_OPEN_CURLY_BRACES) or {$ (T_CURLY_OPEN) in tst3.php on line 4


I've spent some time figuring this out. Why did they change php 5 behaviour?
C
Channaveer Hakari

I would usually go with the following code in my plain PHP projects.

if(!defined('ENVIRONMENT')){
    define('ENVIRONMENT', 'DEVELOPMENT');
}

$base_url = null;

if (defined('ENVIRONMENT'))
{
    switch (ENVIRONMENT)
    {
        case 'DEVELOPMENT':
            $base_url = 'http://localhost/product/';
            ini_set('display_errors', 1);
            ini_set('display_startup_errors', 1);
            error_reporting(E_ALL|E_STRICT);
            break;

        case 'PRODUCTION':
            $base_url = 'Production URL'; /* https://google.com */
            error_reporting(0);
            /* Mechanism to log errors */
            break;

        default:
            exit('The application environment is not set correctly.');
    }
}

j
jxmallett

If, despite following all of the above answers (or you can't edit your php.ini file), you still can't get an error message, try making a new PHP file that enables error reporting and then include the problem file. eg:

error_reporting(E_ALL);
ini_set('display_errors', 1);
require_once('problem_file.php');

Despite having everything set properly in my php.ini file, this was the only way I could catch a namespace error. My exact scenario was:

//file1.php
namespace a\b;
class x {
    ...
}

//file2.php
namespace c\d;
use c\d\x; //Dies because it's not sure which 'x' class to use
class x {
    ...
}

No, the error reporting is not a loglevel, it is a bitfield. Using 999999 is a very bad idea, use some power-of-two minus 1, for example 2047!
You're absolutely right, @peterh! I've changed it to E_ALL as this will enable reporting of all errors (except strict errors in php 5.4 and below).
c
chiborg

If you somehow find yourself in a situation where you can't modifiy the setting via php.ini or .htaccess you're out of luck for displaying errors when your PHP scripts contain parse errors. You'd then have to resolve to linting the files on the command line like this:

find . -name '*.php' -type f -print0 | xargs -0 -n1 -P8 php -l | grep -v "No syntax errors"

If your host is so locked down that it does not allow changing the value via php.ini or .htaccess, it may also disallow changing the value via ini_set. You can check that with the following PHP script:

<?php
if( !ini_set( 'display_errors', 1 ) ) {
  echo "display_errors cannot be set.";
} else {
  echo "changing display_errors via script is possible.";
}

find . -name '*.php' -type f -exec php -l {} \; | grep -v 'No syntax errors detected' is simpler
P
Peter Mortensen

You can do something like below:

Set the below parameters in your main index file:

    ini_set('display_errors', 1);
    ini_set('display_startup_errors', 1);

Then based on your requirement you can choose which you want to show:

For all errors, warnings and notices:

    error_reporting(E_ALL); OR error_reporting(-1);

For all errors:

    error_reporting(E_ERROR);

For all warnings:

    error_reporting(E_WARNING);

For all notices:

    error_reporting(E_NOTICE);

For more information, check here.


What is the "main index file"? File index.html?
P
Peter Mortensen

You can add your own custom error handler, which can provide extra debug information. Furthermore, you can set it up to send you the information via email.

function ERR_HANDLER($errno, $errstr, $errfile, $errline){
    $msg = "<b>Something bad happened.</b> [$errno] $errstr <br><br>
    <b>File:</b> $errfile <br>
    <b>Line:</b> $errline <br>
    <pre>".json_encode(debug_backtrace(), JSON_PRETTY_PRINT)."</pre> <br>";

    echo $msg;

    return false;
}

function EXC_HANDLER($exception){
    ERR_HANDLER(0, $exception->getMessage(), $exception->getFile(), $exception->getLine());
}

function shutDownFunction() {
    $error = error_get_last();
    if ($error["type"] == 1) {
        ERR_HANDLER($error["type"], $error["message"], $error["file"], $error["line"]);
    }
}

set_error_handler ("ERR_HANDLER", E_ALL & ~E_NOTICE & ~E_STRICT & ~E_DEPRECATED);
register_shutdown_function("shutdownFunction");
set_exception_handler("EXC_HANDLER");

P
Peter Mortensen

This code on top should work:

error_reporting(E_ALL);

However, try to edit the code on the phone in the file:

error_reporting =on

w
webcoder.co.uk

Accepted asnwer including extra options. In PHP files for in my DEVELOPMENT apache vhost (.htaccess if you can ensure it doesn't get into production):

ini_set('display_errors', '1');
ini_set('display_startup_errors', '1');
error_reporting(E_ALL);

However, this doesn't make PHP to show parse errors - the only way to show those errors is to modify your php.ini with this line:

display_errors = on

(if you don't have access to php.ini, then putting this line in .htaccess might work too):

// I've added some extra options that set E_ALL as per https://www.php.net/manual/en/errorfunc.configuration.php.
php_flag log_errors on
php_flag display_errors on
php_flag display_startup_errors on
php_value error_reporting 2147483647
php_value error_log /var/www/mywebsite.ext/logs/php.error.log

P
Peter Mortensen

The best/easy/fast solution that you can use if it's a quick debugging, is to surround your code with catching exceptions. That's what I'm doing when I want to check something fast in production.

try {
    // Page code
}
catch (Exception $e) {
    echo 'Caught exception: ',  $e->getMessage(), "\n";
}

For php7, catch (Throwable $e) is better... Or another catch block underneath catch(Error $e)
L
Lahiru Mirihagoda
    <?php
    // Turn off error reporting
    error_reporting(0);

    // Report runtime errors
    error_reporting(E_ERROR | E_WARNING | E_PARSE);

    // Report all errors
    error_reporting(E_ALL);

    // Same as error_reporting(E_ALL);
    ini_set("error_reporting", E_ALL);

    // Report all errors except E_NOTICE
    error_reporting(E_ALL & ~E_NOTICE);
    ?>

While your site is live, the php.ini file should have display_errors disabled for security reasons. However, for the development environment, display_errors can be enabled for troubleshooting.


j
jewelhuq

Just write:

error_reporting(-1);

M
Muhammad Adeel Malik

You can do this by changing the php.ini file and add the following

display_errors = on
display_startup_errors = on

OR you can also use the following code as this always works for me

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

P
Peter Mortensen

If you have Xdebug installed you can override every setting by setting:

xdebug.force_display_errors = 1;
xdebug.force_error_reporting = -1;

force_display_errors Type: int, Default value: 0, Introduced in Xdebug >= 2.3 If this setting is set to 1 then errors will always be displayed, no matter what the setting of PHP's display_errors is. force_error_reporting Type: int, Default value: 0, Introduced in Xdebug >= 2.3 This setting is a bitmask, like error_reporting. This bitmask will be logically ORed with the bitmask represented by error_reporting to dermine which errors should be displayed. This setting can only be made in php.ini and allows you to force certain errors from being shown no matter what an application does with ini_set().


b
baduker

You might want to use this code:

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

S
Shaikh Nadeem

Report all errors except E_NOTICE

error_reporting(E_ALL & ~E_NOTICE);

Display all PHP errors

error_reporting(E_ALL);  or ini_set('error_reporting', E_ALL);

Turn off all error reporting

error_reporting(0);

P
Peter Mortensen

If it is on the command line, you can run php with -ddisplay_errors=1 to override the setting in php.ini:

php -ddisplay_errors=1 script.php

K
Kwed
     error_reporting(1);
     ini_set('display_errors', '1');
     ini_set('display_startup_errors', '1');
     error_reporting(E_ALL);

Put this at the top of your page.


r
ropehapi

Input this on the top of your code

ini_set('display_errors', '1');
ini_set('display_startup_errors', '1');
error_reporting(E_ALL);

And in the php.ini file, insert this:

display_errors = on

This must work.


D
Devsaiful

You can show Php error in your display via simple ways. Firstly, just put this below code in your php.ini file.

display_errors = on;

(if you don't have access to php.ini, then putting this line in .htaccess might work too):

php_flag display_errors 1

OR you can also use the following code in your index.php file

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

N
NVRM

In Unix CLI, it's very practical to redirect only errors to a file:

./script 2> errors.log

From your script, either use var_dump() or equivalent as usual (both STDOUT and STDERR will receive the output), but to write only in the log file:

fwrite(STDERR, "Debug infos\n"); // Write in errors.log^

Then from another shell, for live changes:

tail -f errors.log

or simply

watch cat errors.log

How does that answer this question about PHP?
./script is a php CLI script (hashbang #!/usr/bin/php). You can redirect the php errors in a file this way. This is unix piping. This is not php as CGI.