@section @code{environ}
@findex environ
-POSIX specification: @url{http://www.opengroup.org/susv3xsh/environ.html}
+POSIX specification: @url{http://www.opengroup.org/onlinepubs/9699919799/functions/environ.html}
-Gnulib module: ---
+Gnulib module: environ
Portability problems fixed by Gnulib:
@itemize
+@item
+POSIX does not require this variable to be declared, and it is indeed not
+declared on some platforms:
+MacOS X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, IRIX 6.5, Solaris 10.
+@item
+On MacOS X 10, this variable is not declared. Up to MacOS X 10.4, one can use
+@smallexample
+extern char **environ;
+@end smallexample
+to get the variable declared. This does not work any more, however, in
+shared libraries on MacOS X 10.5. Here is a workaround: Instead, one can use
+@smallexample
+#include <crt_externs.h>
+#define environ (*_NSGetEnviron())
+@end smallexample
+This works at all versions of MacOS X.
@end itemize
Portability problems not fixed by Gnulib:
@itemize
@item
-This variable is missing on some platforms:
-MacOS X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, IRIX 6.5, OSF/1 5.1, Cygwin.
-@item
The address of this variable is not a compile-time constant on some platforms:
mingw.
@end itemize