When will fopen fail?

[John Stanley]

markh at csd4.csd.uwm.edu (Mark William Hopkins) writes:

>    Assuming all the subdirectories are there and writeable (on UNIX or
> MS-DOS), when does
> 
> 		     FP = fopen("...", "w");
> 
> fail and return FP == NULL?

   On MS-DOS, under TC 2.0, all the time. Perror returns "no such file or
directory".