[Feature Request] Spawn the program once, keep reading its STDOUT

This would noticeably reduce resource/CPU utilization.

The idea is to launch the program only once and keep reading its STDOUT and display what was read when a certain marker is detected e.g. a zero byte or a given record separator string or a <tag>.

This way the frequency of content refresh is also determined by the invoked script/program; the refresh occurs as soon as new content is available from that program STDOUT.

This approach can significantly reduce the overhead that comes from launching the program every time the contents needs to be refreshed, especially when the refresh interval is short.