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.

6 files changed, 9 insertions, 2 deletions

diff --git a/src/nng.c b/src/nng.c
index b906431b..c2e3161d 100644
--- a/src/nng.c
+++ b/src/nng.c
@@ -732,6 +732,8 @@ static const struct {
 	{ NNG_EWRITEONLY, "Write only resource" },
 	{ NNG_ECRYPTO, "Cryptographic error" },
 	{ NNG_EPEERAUTH, "Peer could not be authenticated" },
+	{ NNG_ENOARG, "Option requires argument" },
+	{ NNG_EAMBIGUOUS, "Ambiguous option" },
 	{ NNG_EINTERNAL, "Internal error detected" },
 	{ 0, NULL },
 	// clang-format on
diff --git a/src/nng.h b/src/nng.h
index 779612c7..b3acc86c 100644
--- a/src/nng.h
+++ b/src/nng.h
@@ -590,6 +590,8 @@ enum nng_errno_enum {
 	NNG_EWRITEONLY   = 25,
 	NNG_ECRYPTO      = 26,
 	NNG_EPEERAUTH    = 27,
+	NNG_ENOARG       = 28,
+	NNG_EAMBIGUOUS   = 29,
 	NNG_EINTERNAL    = 1000,
 	NNG_ESYSERR      = 0x10000000,
 	NNG_ETRANERR     = 0x20000000,
diff --git a/src/protocol/pair0/pair.c b/src/protocol/pair0/pair.c
index 10498c0a..d3591df9 100644
--- a/src/protocol/pair0/pair.c
+++ b/src/protocol/pair0/pair.c
@@ -12,6 +12,7 @@
 #include <string.h>
 
 #include "core/nng_impl.h"
+#include "protocol/pair0/pair.h"
 
 // Pair protocol.  The PAIR protocol is a simple 1:1 messaging pattern.
 // While a peer is connected to the server, all other peer connection
diff --git a/src/protocol/pipeline0/pull.c b/src/protocol/pipeline0/pull.c
index 76c680c1..ccc1ef40 100644
--- a/src/protocol/pipeline0/pull.c
+++ b/src/protocol/pipeline0/pull.c
@@ -12,6 +12,7 @@
 #include <string.h>
 
 #include "core/nng_impl.h"
+#include "protocol/pipeline0/pull.h"
 
 // Pull protocol.  The PULL protocol is the "read" side of a pipeline.
 
diff --git a/src/protocol/pipeline0/push.c b/src/protocol/pipeline0/push.c
index 1e6cf30e..e77bfe99 100644
--- a/src/protocol/pipeline0/push.c
+++ b/src/protocol/pipeline0/push.c
@@ -12,6 +12,7 @@
 #include <string.h>
 
 #include "core/nng_impl.h"
+#include "protocol/pipeline0/push.h"
 
 // Push protocol.  The PUSH protocol is the "write" side of a pipeline.
 // Push distributes fairly, or tries to, by giving messages in round-robin
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];
 	}