"When screen is invoked, it executes initialization commands that are contained in two files "/etc/screenrc" and then ".screenrc" in the user's home directory.These defaults can be overridden in the following ways: For the global screenrc file screen searches for the environment variable $SYSSCREENRC (this override feature may be disabled at compile-time). The user specific screenrc file is searched for in $SCREENRC, then $HOME/.screenrcIf the command line option -c it given, it specifies the screenrc file to use. No other file is searched and sourced even if they exist. "