fixes #240 nngcat is MIA

This is intended to provide compatibility with, and has been tested
against, legacy nanocat.  There are a few differences though.

At this time support for the alias names (where argv[0] is set to
something like nngreq or somesuch) is missing.

By default this library operations without NNG_FLAG_NONBLOCK on
dial and listen, so that failures here are immediately diagnosable.
(This behavior can be changed with the --async flag.)

By default --pair means PAIRv1, but you can specify --pair0
or --pair1 explicitly.  (There is also a --compat mode, and in
that mode --pair means PAIRv0.  The --compat mode also turns on
NNG_FLAG_NONBLOCK by default.)

The "quoted" mode also quotes tabs.  (Legacy nanocat did not.)

It is possible to connect to *multiple* peers by using the --dial
or --listen (or similar) options multiple times.

Shorthands can be used for long options that are not ambiguous.  For
example, --surv can be used to mean surveyor, but --re is invalid because
it can mean req, rep, or respondent.

We assume you have a reasonable standard C environment.  This won't work
in embedded environments without support for FILE *.

TLS options are missing but to be added soon.

A man page is still to be written.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/supplemental/util/options.c b/src/supplemental/util/options.c
index d8f78deb..a8cc969d 100644
--- a/src/supplemental/util/options.c
+++ b/src/supplemental/util/options.c
@@ -90,7 +90,7 @@ nng_opts_parse(int argc, const char **argv, const nng_optspec *opts, int *val,
 		break;
 	default:
 		// Ambiguous (not match)
-		return (NNG_EINVAL);
+		return (NNG_EAMBIGUOUS);
 		break;
 	}
 
@@ -113,7 +113,7 @@ nng_opts_parse(int argc, const char **argv, const nng_optspec *opts, int *val,
 	} else {
 		i++;
 		if (i >= argc) {
-			return (NNG_EINVAL);
+			return (NNG_ENOARG);
 		}
 		*optarg = argv[i];
 	}