How do I get cURL errors to go into the correct log file?

Question

I have a website running using Apache 2.2.22, PHP 5.3.10, and cURL 7.2.00. The relevant portions of the apache config is below, and you will notice that errors are sent to www.example.com_error.log.

<VirtualHost *:443>
    ServerName example.com
    ServerAlias www.example.com

    # *snip*

    ErrorLog ${APACHE_LOG_DIR}/example.com_error.log
    LogLevel warn
    CustomLog ${APACHE_LOG_DIR}/example.com_access.log combined
</VirtualHost>

However, when I use cURL from within PHP and turn verbose logging on using curl_setopt($connection, CURLOPT_VERBOSE, true); the output from cURL goes into Apache's error.log instead of the custom logfile I defined above. Why is this, and how can I get cURL's output to go into the correct log file?

Answer 1

Per some answers to this SO question, php logs to the default Apache server log (error.log) as you've already noticed. You can set the php log settings like so:

<VirtualHost *:443>
    ServerName example.com
    ServerAlias www.example.com

    # *snip*

    ErrorLog ${APACHE_LOG_DIR}/example.com_error.log
    LogLevel warn
    CustomLog ${APACHE_LOG_DIR}/example.com_access.log combined

    php_flag log_errors on
    php_flag display_errors on
    php_value error_reporting 2147483647
    php_value error_log ${APACHE_LOG_DIR}/php.error.log
</VirtualHost>

Alternatively, one answer in that SO question mentioned unsetting the error_log directive completely in php.ini to log to the relevant virtual host's logs, e.g. example.com_error.log.

Answer 2

According to curl documentation, You can set log file location with CURLOPT_STDERR.

See complete example in this answer