what does this sed expr. match actually? s/^.*EngineLog ERROR://

sed Expression 's/^.*EngineLog ERROR://开发者_运维技巧'

It matches anything that starts 0 or more characters then EngineLog ERROR: and then replaces it with nothing

Example all output the same: EngineLog ERROR:
:

1EngineLog ERROR:
1 EngineLog ERROR:
EngineLog ERROR: