How to tell if I can open a file or not

[Gordon McMillan]

Donn Cave wrote: 


>One reason it's better than the C way:  sooner or later, you will check
>whether a file can be opened, go ahead to open it on the strength of
>this check, and find that it can't be opened anyway.  Your program
>crashes, the air traffic control system goes out to lunch and hundreds
>die. 
>
>After you check, there's a period of time before you actually open
>the file.  It's a brief window, but it's real, and many things can 
>happen in that time if the system is busy, including changes to the
>file's permission bits or even whether it exists.  Might as well
>just open the file, and if it works then you have a green light.

And hundreds of people die, anyway.

God-am-I-glad-I'm-off-air-traffic-control-ly y'rs

- Gordon