Clear errno before calling readdir() and handle old MinGW errno bug
while adding full test coverage for readdir/closedir failures.
Backpatch through 8.4.
We used to have externs for getopt() and its API variables scattered
all over the place. Now that we find we're going to need to tweak the
variable declarations for Cygwin, it seems like a good idea to have
just one place to tweak.
In this commit, the variables are declared "#ifndef HAVE_GETOPT_H".
That may or may not work everywhere, but we'll soon find out.
Andres Freund
Before, some places didn't document the short options (-? and -V),
some documented both, some documented nothing, and they were listed in
various orders. Now this is hopefully more consistent and complete.
In dry-run mode, just the name of the file to be removed is printed to
stdout; this is so the user can easily plug it into another program
through a pipe. If debug mode is also specified, a more verbose message
is printed to stderr.
Author: Gabriele Bartolini
Reviewer: Josh Kupershmidt
For consistency with other tools, put the options before further usage
information.
In pg_standby, remove the supposedly deprecated -l option from the
given example invocation.
