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Why the plugin failed to work? First, check your php version. This plugin requires php 5. Version 1.1 may work under php4, but has not been tested yet. Then, check your php code and make sure it is correct. If problems still exist, visit Plugin Homepage to report a bug.

I just wish to display <exec>...</exec> rather than execute any code, what should I do? Use <exec off>...</exec> instead; it won't execute anything but display <exec>...</exec> and text in it.