Log Errors on PHP Linux
How to log errors with vanilla PHP on Linux
Watch the full tutorial here:
html
<?php
ini_set("display_errors", 0);
ini_set("log_errors", 1);
ini_set('error_log', '/opt/lampp/htdocs/myproject/log/error.log');
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<?php echo $undefined_variable; ?>
</body>
</html>bash
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1. Create your log folder and file.
cmd: mkdir -p /opt/lampp/htdocs/myproject/logs
cmd: touch /opt/lampp/htdocs/myproject/logs/error.log
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2. Set ownership to Apache user (daemon for XAMPP).
cmd: sudo chown -R daemon:daemon /opt/lampp/htdocs/myproject/logs
note: Apache runs as daemon, so it needs ownership to write logs.
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3. Set secure permissions.
cmd: sudo chmod 750 /opt/lampp/htdocs/myproject/logs
cmd: sudo chmod 640 /opt/lampp/htdocs/myproject/logs/error.log
| Path | Permission | Meaning |
| ----------- | ---------- | ------------------------------------------- |
| `logs/` | `750` | `daemon` can read/write/enter, others cant |
| `error.log` | `640` | `daemon` can write, others can’t access it |
=============================================================================================
4. Set up PHP error logging in your script.
<?php
ini_set("display_errors", 0); // Hide errors from the screen
ini_set("log_errors", 1); // Enable logging
ini_set("error_log", "/opt/lampp/htdocs/myproject/logs/error.log"); // Custom log path
?>
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5. Restart Apache.
cmd: sudo /opt/lampp/lampp restart
Apache needs to reload configuration and file permissions.
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6. Test logging.
Add this to your PHP page to trigger a warning:
<?php echo $undefined_variable; ?>
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7. Optional: Give yourself read access.
Check if your are in the groud.
cmd: groups
Example of what your should see.
yourusername daemon adm cdrom sudo dip www-data plugdev lpadmin sambashare
If your user isn’t in the daemon group, but you still want to read the log:
cmd: sudo chmod g+r /opt/lampp/htdocs/myproject/logs/error.log
Or add yourself to the daemon group (requires logout/login):
cmd: sudo usermod -aG daemon yourusername
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Note.
If daemon dont work, check what apache is using.
cmd: ps aux | grep httpd
Example of what you should see:
root 14778 0.4 0.7 345472 27508 ? Ss 13:56 0:00 /opt/lampp/bin/httpd -k start -E /opt/lampp/logs/error_log -DSSL -DPHP
daemon 14785 0.0 0.3 339700 11444 ? S 13:56 0:00 /opt/lampp/bin/httpd -k start -E /opt/lampp/logs/error_log -DSSL -DPHP
daemon 14820 0.0 0.4 346008 15748 ? S 13:56 0:00 /opt/lampp/bin/httpd -k start -E /opt/lampp/logs/error_log -DSSL -DPHP
In my case apache run with daemon, But if you see.
root 14778 0.4 0.7 345472 27508 ? Ss 13:56 0:00 /opt/lampp/bin/httpd -k start -E /opt/lampp/logs/error_log -DSSL -DPHP
www-data 14785 0.0 0.3 339700 11444 ? S 13:56 0:00 /opt/lampp/bin/httpd -k start -E /opt/lampp/logs/error_log -DSSL -DPHP
www-data 14820 0.0 0.4 346008 15748 ? S 13:56 0:00 /opt/lampp/bin/httpd -k start -E /opt/lampp/logs/error_log -DSSL -DPHP
Change daemon for www-data.
cmd: sudo chown -R www-data:www-data /opt/lampp/htdocs/myproject/logs
cmd: sudo usermod -aG www-data yourusername
Remember to close session.
add this: (Require all denied) to your .htaccess in your log directory