>>>>> A good replacement for a broken putenv() is (assuming that `putenv'
>>>> is defined as `rpl_putenv'):
>>>>
>>>> #undef putenv
>>>> int rpl_putenv(s)
>>>> char *s;
>>>> {
>>>> char *t;
>>>> strcpy(t, s);
>>>> return putenv(t);
>>>> }
>>>> The strcpy() call has an undefined effect as it dereferences an
>>> uninitialised pointer. Perhaps you meant to put a call to xmalloc()
>>> or strdup() in there.
>>>> If so, what about those callers who already carefully did this: -
>>>> /* Assume no other thread will modify var or val; also assume
>>> * we already hold a mutex controlling access to putenv().
>>> */
>>> size_t len = strlen(var) + 1u + strlen(val);
>>> char *s = xmalloc(len + 1u);
>>> snprintf(s, len+1u, "%s=%s", var, val);
>>> rpl_putenv(s);
>>>> ... because then you would have a memory leak.
>>> I think I accenditly reversed the argumnts. In that case, I'll
>> replace the strcpy() with
>>
>> int n = 0;
>> while (*t++ = *s++)
>> ++n;
>> while (n-- > 0)
>> *t--;
>>
>> Samuel Lauber
>>
>> P.S. If you were wondering, the first `while' loop was in Chapter
>> 5 of `The C Programming Langauge'. The second `while' was added
>> to make sure that putenv() would get the address of the beginning
>> of the string.
> No, the first while loop is still wrong because "t" is never
> initialised. Also the second while loop is identical to just "n=0;"
> apart from the fact that it has undefined behaviour because it
> dereferences the uninitialised pointer, "t".
Ok, I give up! Any way to copy said string is very
welcome. If strcpy() does not do it's thing, what will?
Samuel Lauber
--
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