2.9BSD/usr/contrib/mh/strings/sysed.c

/*
 * This is the editor invoked by the various message composition
 * programs.  It SHOULD be a 2-D scope editor, such as Rand's Ned
 * or Berkeley's ex, but any editor will work.  If you don't have
 * a scope editor, you might want to default to prompter, but it
 * works very marginally with forw and dist.
 */

char    *sysed =        "/bin/ex";