Re: Reading environment variables in ADA?

[Simon Wright <simon@pogner.demon.co.uk>]

eachus@spectre.mitre.org (Robert I. Eachus) writes:

> In article <6vfgvo$ja0$1@nnrp1.dejanews.com> dewarr@my-dejanews.com writes:
> 
>   > I find this a specious argument, it would equally well apply to constants
>   > at the global level which you allowed C to modify, and there is no way of
>   > generating inefficient code to allow this to "work" whatever that means.
> 
>   > A constant is a constant, it cannot be modified after declaration
>   > time. If you have your C code modify it that is morally equivalent
>   > to having C destroy your Ada generated code by poking at it. This
>   > is just plain junk buggy code, and it is absurd to generate
>   > deliberately suboptimal code so that this particularly bug can be
>   > got away with!
> 
>    Agreed, it is absurd, but it is also, unfortunately, practical
> advice, especially in the case of environment variables. (See the
> man page from SunOS atttached.) I don't like creating storage leaks,
> but the Ada version of putenv I use explicitly allocates heap space
> and forgets about it after the return.  Much easier than finding the
> insidious bugs caused when it is called with a stack or constant
> value.

[putenv man page snipped]

and I recently got bitten by openlog on Solaris for the same reason.

However, I certainly don't think that compilers should generate
inefficient code because of potential OS/library problems like this, as
Robert seemed to say; programmers may have to write inefficient code,
of course.