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  


SUB opener (a$)
    WHEN EXCEPTION IN
         OPEN #1: NAME f$
         PRINT f$; " exists"
    USE
         PRINT f$; " not exists"
    END WHEN
    CLOSE #1
END SUB
 
LET f$ = "input.txt"
CALL opener (f$)
LET f$ = "\input.txt"
CALL opener (f$)
LET f$ = "docs\nul"
CALL opener (f$)
LET f$ = "\docs\nul"
CALL opener (f$)
 
LET f$ = "empty.tru"
CALL opener (f$)
LET f$ = "`Abdu'l-Bahá.txt"
CALL opener (f$)
END