Taco Hoekwater writes:

Hi David,

...

b) don't bother about the leak and use setenv instead.

Option b) would be somewhat more portable, I believe.

Rationale: it is not more portable, because win32 doesn't have it (and Solaris is unknown).

Great. The posixified manual page for "setenv" says this on Ubuntu: RATIONALE Unanticipated results may occur if setenv() changes the external variable environ. In particular, if the optional envp argument to main() is present, it is not changed, and thus may point to an obsolete copy of the environment (as may any other copy of environ). However, other than the aforementioned restriction, the developers of IEEE Std 1003.1-2001 intended that the traditional method of walking through the environment by way of the environ pointer must be supported. It was decided that setenv() should be required by this revision because it addresses a piece of missing functionality, and does not impose a significant burden on the implementor. There was considerable debate as to whether the System V putenv() function or the BSD setenv() function should be required as a mandatory function. The setenv() function was chosen because it permitted the implementation of the unsetenv() function to delete environmental variables, without specifying an additional interface. The putenv() function is available as an XSI extension. So it would appear that Posix chose to standardize one interface, and win32 picked another (the term "standardize" does not apply here really). Anyway, option a) presumably also would require to place the table keeping score of environment variables into Lua context 0, in order to make sure that it remains available until LuaTeX exits. -- David Kastrup

Taco Hoekwater writes:

...

Anyway, option a) presumably also would require to place the table keeping score of environment variables into Lua context 0, in order to make sure that it remains available until LuaTeX exits.

There is an os.env table already, but it is initialized only once. In any case, I will probably move to the 'ex' interface soon instead of my own code+LuaFileSystem:

http://lua-users.org/wiki/ExtensionProposal

Well, one probably needs to wait at least until the namespace question discussed on that page has been cleared. A good security model will probably remain an area good for headaches. -- David Kastrup

Arthur Reutenauer writes:

[setenv]

...

Rationale: it is not more portable, because win32 doesn't have it (and Solaris is unknown).

No, Solaris doesn't have it either.

That's the great thing about standards. People can agree on the best thing to do, and then ignore it. Sorry, I just assumed from reading the Posix manpage for that functionality that one could expect setenv but not putenv in general. Maybe there are strict Posix systems without XSI (?) around, in which case one would need to use setenv. Perhaps a case for autoconf? -- David Kastrup

Taco Hoekwater writes:

David Kastrup wrote:

...

Maybe there are strict Posix systems without XSI (?) around, in which case one would need to use setenv.

That is true, we just haven't found one yet.

...

Perhaps a case for autoconf?

I much prefer to have a target-specific compiles via the makefile, like lua itself does. Autotools is a disaster unless you are willing to ignore all commercial platforms (including quite a few unices).

Hm? The GNU stuff is portable across a lot of platforms, not least because of using autoconf.

But I have not gotten around to setting that up, so for the moment I simply write adhoc code with a few ifdefs.

The problem with the ifdefs is that the person writing a particular line of code rarely has access to the dozen or more platforms where it might need to run on. So he does not necessarily know what to put in that ifdef. Autoconf might not be the prettiest system around, but as far as I can see, it does its job. -- David Kastrup

Here I was speaking of Solaris 9 (dating back to 1999), I have yet to check for Solaris 10

Solaris 10 has setenv and is POSIX.1-2001 compliant (see http://docs.sun.com/app/docs/doc/816-5168/6mbb3hrr3?a=view for setenv and http://docs.sun.com/app/docs/doc/816-5175/6mbba7f3i?a=view for an overview of the standards Solaris conform to).