<!--Copyright (C) 1988-2005 by the Institute of Global Environment and Society (IGES). See file COPYRIGHT for more information.--> <h2>!shell-command</h2> Any expression preceded by a <code>!</code> will be executed as a shell command from the GrADS command line. <H3>Usage Notes</H3> <P> Output from the shell command will be displayed in the Grads command window. If the shell command is executed from a Grads script, the output will not returned as a string buffer to the script.