How can the issue of receiving NULL when executing shell_exec be resolved?

When receiving NULL when executing shell_exec in PHP, it may be due to restrictions set in the php.ini file or the command not being found in the system's PATH. To resolve this issue, you can specify the full path to the command you want to execute or adjust the PHP configuration to allow the execution of the command.

$output = shell_exec('/full/path/to/your/command');
echo $output;