Command: system
  
Syntax: 
  r = system_exec(s, i)
  
Description: 
  Pass a command string s to the command interpreter
  for execution. 
  
  r give the return code of the requested program .
  This is the abort or error code .
  
  The argument i indicates the manner in which to 
  return from the system call. 
  
  value of i      return action (not used in PEU )
  ----------------------- 
  0      - restore previous graphics mode
  (clears the screen)
  1      - make a beep sound, wait for a
  key press, then restore the
  graphics mode
  2      - do not restore graphics mode
  
Comments: 
  Action 2 should only be used when it is known that the system 
  call will not change the graphics mode. 
   
Example: 
     r = system("copy temp.txt c:\\temp.bak", 2)  --Dos , Windows
       -- note use of double backslash in literal string to get 
          single backslash
          
     r = system("cp -f temp.txt ../temp.bak", 2)  --Linux
     
     If there is no error r should be 0 .
     
See Also: 
  dir, current_dir, getenv, command_line, system_exec
  
