7ca37fb040
Since at least 2001 we've used putenv() and avoided setenv(), on the grounds that the latter was unportable and not in POSIX. However, POSIX added it that same year, and by now the situation has reversed: setenv() is probably more portable than putenv(), since POSIX now treats the latter as not being a core function. And setenv() has cleaner semantics too. So, let's reverse that old policy. This commit adds a simple src/port/ implementation of setenv() for any stragglers (we have one in the buildfarm, but I'd not be surprised if that code is never used in the field). More importantly, extend win32env.c to also support setenv(). Then, replace usages of putenv() with setenv(), and get rid of some ad-hoc implementations of setenv() wannabees. Also, adjust our src/port/ implementation of unsetenv() to follow the POSIX spec that it returns an error indicator, rather than returning void as per the ancient BSD convention. I don't feel a need to make all the call sites check for errors, but the portability stub ought to match real-world practice. Discussion: https://postgr.es/m/2065122.1609212051@sss.pgh.pa.us
The PostgreSQL contrib tree
---------------------------
This subtree contains porting tools, analysis utilities, and plug-in
features that are not part of the core PostgreSQL system, mainly
because they address a limited audience or are too experimental to be
part of the main source tree. This does not preclude their
usefulness.
User documentation for each module appears in the main SGML
documentation.
When building from the source distribution, these modules are not
built automatically, unless you build the "world" target. You can
also build and install them all by running "make all" and "make
install" in this directory; or to build and install just one selected
module, do the same in that module's subdirectory.
Some directories supply new user-defined functions, operators, or
types. To make use of one of these modules, after you have installed
the code you need to register the new SQL objects in the database
system by executing a CREATE EXTENSION command. In a fresh database,
you can simply do
CREATE EXTENSION module_name;
See the PostgreSQL documentation for more information about this
procedure.