Re: VMS

On Tue, 24 Jun 2025 04:52:21 GMT, Charlie Gibbs wrote:

On 2025-06-24, Robert Riches <spamtrap42@jacob21819.net> wrote:
 

IIUC, heap-based malloc _usually_ returns a larger allocation block
than you really asked for.  As long as malloc gave you at least 2 extra
bytes, you'd never see any misbehavior.  Even if it didn't give you 2
or more extra bytes, it's fairly likely you'd just get lucky and never
see the program crash or otherwise misbehavior in a significant way.

 
Or if malloc() rounds the size of the block up to, say, the next
multiple of 8, odds are good that you'll be clobbering an unused byte.
 

                                   For example, if you stomped on
the header of the next allocation block, as long as nothing ever read
and acted upon the data in said header, you'd never see it.

 
If you wrote a NUL to a byte that's normally zero, you might still get
away with it even if that header is referenced.
 
But worst case, a program that ran flawlessly for years might suddenly
bomb because you happened to write a different number of bytes to the
area than you normally do.  That one can be a nightmare to debug.

"Do you feel lucky, punk?" isn't a great programming philosophy.