Re: [bug-inetutils] netstat

[Alfred M. Szmidt]

   >    If we can't rely on error messages (which seems like the best approach
   >    -- then we will test this aspect of the tool as well), we should be able
   >    to write a small tool that tries to bind a particular port.  This tool
   >    could replace InetUtils' use of netstat.
   > 
   > I wrote such a tool once, port-open-p, but never had time to
   > polish it up and commit it.  I think we should do this after
   > release, but then I'm not in a hurry.  Such a tool would be
   > useful, but syslogd should exist gracefully if it can't open a
   > port and report an error even if we have such a tool.

   Personally, I find it reasonable to demand a basic tool like
   netstat(1), if it is agreed that bison(1) must be present.

bison is only required for maintainers, it isn't required when you
build, nor can bison be required when you run the test suite.  The
problem with netstat is that we want people to run `make all check
install', which excludes any `non-portable' commands (of which netstat
is one); having our own version of `netstat', and/or check if a port
is open either via syslogd reporting it, or an explicit command would
make our life a lot easier.

   NixOS has complained with us for demanding use of netstat, which
   their build daemon does not provide.  On the other hand, NixOS does
   not even provide "/etc/services", which makes any testing of
   network code utterly pointless, breaking the needed library calls.

True that, that is a serious bug in NisOS which makes it totally
unusable for our purposes.

   However, in Solaris and relatives, netstat(1) produces completely
   different output, so the grep-patterns in our test script is
   utterly useless; see below for a filtered version. Some sort of
   micro-netstat for reporting a single occupied port, built for our
   tests, could be of benefit.

Exactly! :-)