       10 // OS test program
       20 //
       30 CASE SYS$(host) OF
       40 WHEN "MsDos"
       50   OS "ver"
       60 WHEN "Linux", "MacOS"
       70   OS "uname -a"
       80 OTHERWISE
       90   PRINT "Unknown host"
      100   SYS assert,FALSE
      110 ENDCASE
      120 //
      130 PRINT "Ok"
