Task

Verify that a file called     input.txt     and   a directory called     docs     exist.



This should be done twice:  

   once for the current working directory,   and
   once for a file and a directory in the filesystem root.


Optional criteria (May 2015):   verify it works with:

   zero-length files
   an unusual filename:     `Abdu'l-Bahá.txt  


   OPEN(FIle=   'input.txt', OLD, IOStat=ios, ERror=99)
   OPEN(FIle='C:\input.txt', OLD, IOStat=ios, ERror=99)
! ...
99 WRITE(Messagebox='!') 'File does not exist. Error message ', ios 