On Fri, 30 May 2003, Simon Burge wrote:

    8<   snip   >8

> I've got the following in a program I use (a multi-timezone hack for
> xclock).  This is near the start of the program:
>
>         /*
>          * XXX: The longestlen, longest, setenv business is described
>          * in Clock.c - look for
>          *      XXX - this is not pretty
>          */
>         int i, longestlen;
>         char *longest;
>
>         ntimezones = argc - 1;
>         timezones = (char **)malloc(argc * sizeof(char *));
>
>         longestlen = 0;
>         for (i = 0; i < ntimezones; i++) {
>             timezones[i] = argv[i + 1];
>             if (strlen(timezones[i]) > longestlen) {
>                 longest = timezones[i];
>                 longestlen = strlen(timezones[i]);
>             }
>         }
>         setenv("TZ", longest, 1);
>
> and this is in the loop where I want to call localtime with different
> timezones:
>
> #ifdef want_memory_leak
>                     setenv("TZ", tz, 1);
> #else
>                     /* XXX - this is not pretty!  but setenv() leaks memory :-( */
>                     char *envptr;
>                     envptr = getenv("TZ");
>                     strcpy(envptr, tz);
> #endif
>                     tm = *localtime(&time_value);

I actually thought of that, but then I found the following in the man
page for setenv(3) under Return Values:

	If getenv() is successful, the string returned should be
	considered read-only.

It would be really nice to solve this in a portable manner!  :)

> Not nice, but get's the job done.  Having something like a
> localtime_tz(3) with an extra arg for the timezone would be nice...

Yup, that would be a Good Thing.

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