Bump version, update NEWS

Apparently it's reached maturity and there won't be any changes
anytime soon, making this the perfect time for an upgrade.

CMakeLists.txt

@@ -13,7 +13,7 @@ if ("${CMAKE_C_COMPILER_ID}" MATCHES "GNU" OR CMAKE_COMPILER_IS_GNUCC)
 endif ("${CMAKE_C_COMPILER_ID}" MATCHES "GNU" OR CMAKE_COMPILER_IS_GNUCC)
 
 # Version
-set (project_VERSION_MAJOR "0")
+set (project_VERSION_MAJOR "1")
 set (project_VERSION_MINOR "1")
 set (project_VERSION_PATCH "0")
 
@@ -87,18 +87,20 @@ install (PROGRAMS json-format.pl DESTINATION ${CMAKE_INSTALL_BINDIR})
 install (FILES LICENSE DESTINATION ${CMAKE_INSTALL_DOCDIR})
 
 # Generate documentation from program help
-find_program (HELP2MAN_EXECUTABLE help2man)
-if (NOT HELP2MAN_EXECUTABLE)
-	message (FATAL_ERROR "help2man not found")
-endif (NOT HELP2MAN_EXECUTABLE)
+find_program (ASCIIDOCTOR_EXECUTABLE asciidoctor)
+if (NOT ASCIIDOCTOR_EXECUTABLE)
+	message (FATAL_ERROR "asciidoctor not found")
+endif (NOT ASCIIDOCTOR_EXECUTABLE)
 
 foreach (page ${PROJECT_NAME})
 	set (page_output "${PROJECT_BINARY_DIR}/${page}.1")
 	list (APPEND project_MAN_PAGES "${page_output}")
 	add_custom_command (OUTPUT ${page_output}
-		COMMAND ${HELP2MAN_EXECUTABLE} -N
-			"${PROJECT_BINARY_DIR}/${page}" -o ${page_output}
-		DEPENDS ${page}
+		COMMAND ${ASCIIDOCTOR_EXECUTABLE} -b manpage
+			-a release-version=${project_VERSION}
+			"${PROJECT_SOURCE_DIR}/${page}.adoc"
+			-o "${page_output}"
+		DEPENDS ${page}.adoc
 		COMMENT "Generating man page for ${page}" VERBATIM)
 endforeach (page)
 
@@ -111,7 +113,8 @@ foreach (page ${project_MAN_PAGES})
 endforeach (page)
 
 # CPack
-set (CPACK_PACKAGE_DESCRIPTION_SUMMARY "Shell for running JSON-RPC 2.0 queries")
+set (CPACK_PACKAGE_DESCRIPTION_SUMMARY
+	"A shell for running JSON-RPC 2.0 queries")
 set (CPACK_PACKAGE_VENDOR "Premysl Eric Janouch")
 set (CPACK_PACKAGE_CONTACT "Přemysl Eric Janouch <p@janouch.name>")
 set (CPACK_RESOURCE_FILE_LICENSE "${PROJECT_SOURCE_DIR}/LICENSE")

NEWS

@@ -0,0 +1,15 @@
+1.1.0 (2020-10-13)
+
+ * Add method name tab completion using OpenRPC information
+
+ * Bind M-Enter to insert a newline into the command line
+
+ * json-rpc-test-server: fix a memory leak and request URI parsing
+
+ * Miscellaneous bug fixes
+
+
+1.0.0 (2020-09-05)
+
+ * Initial release
+

README.adoc

@@ -17,38 +17,29 @@ you get the following niceties:
  - ability to pipe output through a shell command, so that you can view the
    results in your favourite editor or redirect them to a file
  - ability to edit the input line in your favourite editor as well with Alt+E
+ - WebSockets (RFC 6455) can also be used as a transport rather than HTTP
+ - support for method name tab completion using OpenRPC discovery
 
-Supported transports
---------------------
- - HTTP
- - HTTPS
- - WebSocket
- - WebSocket over TLS
-
-WebSockets
-~~~~~~~~~~
-The JSON-RPC 2.0 spec doesn't say almost anything about underlying transports.
-The way it's implemented here is that every request is sent as a single text
-message.  If it has an "id" field, i.e. it's not just a notification, the
-client waits for a message from the server in response.
-
-There's no support so far for any protocol extensions, nor for specifying
-the higher-level protocol (the "Sec-Ws-Protocol" HTTP field).
+Documentation
+-------------
+See the link:json-rpc-shell.adoc[man page] for information about usage.
+The rest of this README will concern itself with externalities.
 
 Packages
 --------
 Regular releases are sporadic.  git master should be stable enough.  You can get
 a package with the latest development version from Archlinux's AUR.
 
-Building and Usage
-------------------
-Build dependencies: CMake, pkg-config, help2man,
+Building
+--------
+Build dependencies: CMake, pkg-config, asciidoctor,
                     liberty (included), http-parser (included) +
 Runtime dependencies: libev, Jansson, cURL, openssl,
                       readline or libedit >= 2013-07-12,
 
 Avoid libedit if you can, in general it works but at the moment history is
-acting up and I have no clue about fixing it.
+acting up and I have no clue about fixing it.  Multiline editing is also
+misbehaving there.
 
  $ git clone --recursive https://git.janouch.name/p/json-rpc-shell.git
  $ mkdir json-rpc-shell/build
@@ -68,13 +59,12 @@ Or you can try telling CMake to make a package for you.  For Debian it is:
 Note that for versions of CMake before 2.8.9, you need to prefix `cpack` with
 `fakeroot` or file ownership will end up wrong.
 
-Run the program with `--help` to obtain usage information.
-
 Test server
 -----------
 If you install development packages for libmagic, an included test server will
 be built but not installed which provides a trivial JSON-RPC 2.0 service with
-FastCGI, SCGI, and WebSocket interfaces.  It responds to the `ping` method.
+FastCGI, SCGI, and WebSocket interfaces.  It responds to `ping` and `date`
+methods and it can serve static files.
 
 Contributing and Support
 ------------------------

json-rpc-shell.adoc

@@ -0,0 +1,183 @@
+json-rpc-shell(1)
+=================
+:doctype: manpage
+:manmanual: json-rpc-shell Manual
+:mansource: json-rpc-shell {release-version}
+
+Name
+----
+json-rpc-shell - a simple JSON-RPC 2.0 shell
+
+Synopsis
+--------
+*json-rpc-shell* [_OPTION_]... _ENDPOINT_
+
+Description
+-----------
+The _ENDPOINT_ must be either an HTTP or a WebSocket URL, with or without TLS
+(i.e. one of the _+++http+++://_, _+++https+++://_, _ws://_, _wss://_ schemas).
+
+*json-rpc-shell* will use it to send any JSON-RPC 2.0 requests you enter on its
+command line. The server's response will be parsed and validated, stripping it
+of the protocol's noisy envelope.  At your option, it can then also be
+pretty-printed, rendered with adjustable syntax highlighting, or even piped
+through another program such as the *less*(1) pager or the *jq*(1) JSON
+processor.
+
+Usage
+~~~~~
+Three things may appear on the internal command line, in a sequence.  The first
+one is always the name of the JSON-RPC method to call, as a bare word, separated
+from the rest by white space.  Following that, you may enter three kinds of JSON
+values.  If it is an object or an array, it constitutes the method parameters.
+If it is a string or a number, it is taken as the "id" to use for the request,
+which would be chosen for you automatically if left unspecified.  Finally,
+a null value indicates that the request should be sent as a notification,
+lacking the ID completely.  Booleans cannot be used for anything.
+
+The response to the method call may be piped through external commands, the same
+way you would do it in a Unix shell.
+
+Exit the program by pressing C-c or C-d.  No special keywords are reserved for
+this action as they might conflict with method names.
+
+Options
+-------
+Controlling output
+~~~~~~~~~~~~~~~~~~
+*-c*, *--compact-output*::
+	Do not pretty-print responses.  Normally, spaces and newlines are added
+	where appropriate to improve readability.
+
+*--color*=_WHEN_::
+	By default, when the output of the program is a terminal, JSON responses
+	are syntax-highlighted.  This corresponds to the _auto_ setting.  You may
+	also set this to _always_ or _never_.  In either case, color is never
+	applied when piping to another program.
+
+*-v*, *--verbose*::
+	Print raw requests and responses, including the JSON-RPC 2.0 envelope.
+
+*-d*, *--debug*::
+	Print even more information to help debug various issues.
+
+Protocol
+~~~~~~~~
+*-n*, *--null-as-id*::
+	Normally, entering a null JSON value on the command line causes
+	a notification to be sent.  With this option, it is sent as the "id"
+	field of a normal request, which is discouraged by the specification.
+
+*-t*, *--trust-all*::
+	Trust all SSL/TLS certificates.  Useful in case that the certificate is
+	self-signed, or when the CA isn't in your CA store.  Beware that this option
+	is about as good as using plain unencrypted HTTP.
+
+*-o* _ORIGIN_, *--origin*=_ORIGIN_::
+	Set the HTTP Origin header to _ORIGIN_.  Some servers may need this.
+
+*-O*, *--openrpc*::
+	Call "rpc.discover" upon start-up in order to pull in OpenRPC data for
+	tab completion of method names.
+
+Program information
+~~~~~~~~~~~~~~~~~~~
+*-h*, *--help*::
+	Display a help message and exit.
+
+*-V*, *--version*::
+	Output version information and exit.
+
+*--write-default-cfg*[**=**__PATH__]::
+	Write a default configuration file, show its path and exit.
+
+Files
+-----
+_~/.config/json-rpc-shell/json-rpc-shell.conf_::
+	The configuration file, in which you can configure color output and
+	CA certificate paths.  Use the *--write-default-cfg* option to create
+	a new one for editing.
+
+_~/.local/share/json-rpc-shell/history_::
+	All your past method invocations are stored here upon exit and loaded back
+	on start-up.
+
+Notes
+-----
+Editing
+~~~~~~~
+While single-line editing on the command line may be satisfactory for simple
+requests, it is often convenient or even necessary to run a full text editor
+in order to construct complex objects or arrays, and may even be used to import
+data from elsewhere.  You can launch an editor for the current request using
+the M-e key combination.  Both *readline*(3) and *editline*(7) also support
+multiline editing natively, though you need to press C-v C-j in order to insert
+newlines.
+
+WebSockets
+~~~~~~~~~~
+The JSON-RPC 2.0 specification doesn't say almost anything about underlying
+transports.  The way it's implemented here is that every request is sent as
+a single text message.  If it has an "id" field, i.e., it's not just
+a notification, the client waits for a message from the server in response.
+Should any message arrive unexpectedly, you will receive a warning.
+
+There is no support so far for any protocol extensions, nor for specifying
+the higher-level protocol (the "Sec-Ws-Protocol" HTTP field).
+
+Bugs
+----
+The editline (libedit) frontend is more of a proof of concept that mostly seems
+to work but exhibits bugs that are not our fault.
+
+Examples
+--------
+Running some queries against json-rpc-test-server, included in the source
+distribution of this program (public services are hard to find):
+
+Methods without parameters
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+ $ json-rpc-shell ws://localhost:1234
+ json-rpc> ping
+ "pong"
+ json-rpc> date
+ {
+   "year": 2020,
+   "month": 9,
+   "day": 5,
+   "hours": 2,
+   "minutes": 23,
+   "seconds": 51
+ }
+
+Notification with a parameter
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Notifications never produce a response, not even when the method is not known
+to the server:
+
+ $ json-rpc-shell ws://localhost:1234
+ json-rpc> notify {"events": ["conquest", "war", "famine", "death"]} null
+ [Notification]
+
+Piping in and out
+~~~~~~~~~~~~~~~~~
+GNU Readline always repeats the prompt, which makes this a bit less useful
+for invoking from other programs:
+
+ $ echo 'ping | jq ascii_upcase' | json-rpc-shell ws://localhost:1234
+ json-rpc> ping | jq ascii_upcase
+ "PONG"
+
+Reporting bugs
+--------------
+Use https://git.janouch.name/p/json-rpc-shell to report bugs, request features,
+or submit pull requests.
+
+See also
+--------
+*jq*(1), *readline*(3) or *editline*(7)
+
+Specifications
+~~~~~~~~~~~~~~
+https://www.jsonrpc.org/specification +
+https://www.json.org

json-rpc-shell.c

@@ -141,6 +141,8 @@ struct input
 	void (*on_input) (char *line, void *user_data);
 	/// User requested external line editing
 	void (*on_run_editor) (const char *line, void *user_data);
+	/// Tab completion generator, returns locale encoding strings or NULL
+	char *(*complete_start_word) (const char *text, int state);
 };
 
 struct input_vtable
@@ -246,16 +248,42 @@ input_rl_on_run_editor (int count, int key)
 	return 0;
 }
 
+static int
+input_rl_newline_insert (int count, int key)
+{
+	(void) count;
+	(void) key;
+
+	rl_insert_text ("\n");
+	return 0;
+}
+
 static int
 input_rl_on_startup (void)
 {
 	rl_add_defun ("run-editor", input_rl_on_run_editor, -1);
 	rl_bind_keyseq ("\\ee", rl_named_function ("run-editor"));
+	rl_add_defun ("newline-insert", input_rl_newline_insert, -1);
+	rl_bind_keyseq ("\\e\\r", rl_named_function ("newline-insert"));
 	return 0;
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
+static char **
+app_readline_completion (const char *text, int start, int end)
+{
+	(void) end;
+
+	// Only customize matches for the first token, which is the method name
+	if (start)
+		return NULL;
+
+	// Don't iterate over filenames and stuff in this case
+	rl_attempted_completion_over = true;
+	return rl_completion_matches (text, g_input_rl->super.complete_start_word);
+}
+
 static void
 input_rl_start (struct input *input, const char *program_name)
 {
@@ -268,6 +296,9 @@ input_rl_start (struct input *input, const char *program_name)
 	rl_readline_name = slash ? ++slash : program_name;
 	rl_startup_hook = input_rl_on_startup;
 	rl_catch_sigwinch = false;
+	rl_change_environment = false;
+
+	rl_attempted_completion_function = app_readline_completion;
 
 	hard_assert (self->prompt != NULL);
 	rl_callback_handler_install (self->prompt, input_rl_on_input);
@@ -347,8 +378,7 @@ input_rl_show (struct input *input)
 	rl_replace_line (self->saved_line, false);
 	rl_point = self->saved_point;
 	rl_mark = self->saved_mark;
-	free (self->saved_line);
-	self->saved_line = NULL;
+	cstr_set (&self->saved_line, NULL);
 
 	rl_redisplay ();
 }
@@ -357,19 +387,16 @@ static void
 input_rl_set_prompt (struct input *input, char *prompt)
 {
 	struct input_rl *self = (struct input_rl *) input;
-	free (self->prompt);
-	self->prompt = prompt;
+	cstr_set (&self->prompt, prompt);
 
-	if (!self->active)
+	if (!self->active || self->prompt_shown <= 0)
 		return;
 
 	// First reset the prompt to work around a bug in readline
 	rl_set_prompt ("");
-	if (self->prompt_shown > 0)
 	rl_redisplay ();
 
 	rl_set_prompt (self->prompt);
-	if (self->prompt_shown > 0)
 	rl_redisplay ();
 }
 
@@ -616,6 +643,15 @@ input_el_on_run_editor (EditLine *editline, int key)
 	return CC_NORM;
 }
 
+static unsigned char
+input_el_on_newline_insert (EditLine *editline, int key)
+{
+	(void) key;
+
+	el_insertstr (editline, "\n");
+	return CC_REFRESH;
+}
+
 static void
 input_el_install_prompt (struct input_el *self)
 {
@@ -625,6 +661,8 @@ input_el_install_prompt (struct input_el *self)
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
+static unsigned char input_el_on_complete (EditLine *editline, int key);
+
 static void
 input_el_start (struct input *input, const char *program_name)
 {
@@ -642,16 +680,18 @@ input_el_start (struct input *input, const char *program_name)
 	// Just what are you doing?
 	el_set (self->editline, EL_BIND, "^u", "vi-kill-line-prev",   NULL);
 
-	// It's probably better to handle this ourselves
+	// It's probably better to handle these ourselves
 	el_set (self->editline, EL_ADDFN,
 		"send-line", "Send line", input_el_on_return);
 	el_set (self->editline, EL_BIND, "\n", "send-line",           NULL);
-
-	// It's probably better to handle this ourselves
 	el_set (self->editline, EL_ADDFN,
 		"run-editor", "Run editor to edit line", input_el_on_run_editor);
 	el_set (self->editline, EL_BIND, "M-e", "run-editor",         NULL);
 
+	el_set (self->editline, EL_ADDFN,
+		"newline-insert", "Insert a newline", input_el_on_newline_insert);
+	el_set (self->editline, EL_BIND, "M-\n", "newline-insert",    NULL);
+
 	// Source the user's defaults file
 	el_source (self->editline, NULL);
 
@@ -745,8 +785,7 @@ static void
 input_el_set_prompt (struct input *input, char *prompt)
 {
 	struct input_el *self = (struct input_el *) input;
-	free (self->prompt);
-	self->prompt = prompt;
+	cstr_set (&self->prompt, prompt);
 
 	if (self->prompt_shown > 0)
 		input_el_redisplay (self);
@@ -781,6 +820,121 @@ input_el_ding (struct input *input)
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
+static int
+input_el_collate (const void *a, const void *b)
+{
+	return strcoll (*(const char **) a, *(const char **) b);
+}
+
+static struct strv
+input_el_collect_candidates (struct input_el *self, const char *word)
+{
+	struct strv v = strv_make ();
+	int i = 0; char *candidate = NULL;
+	while ((candidate = self->super.complete_start_word (word, i++)))
+		strv_append_owned (&v, candidate);
+	qsort (v.vector, v.len, sizeof *v.vector, input_el_collate);
+	return v;
+}
+
+static void
+input_el_print_candidates (struct input_el *self, const struct strv *v)
+{
+	EditLine *editline = self->editline;
+
+	// This insanity seems to be required to make it reprint the prompt
+	const LineInfoW *info = el_wline (editline);
+	int from_cursor_until_end = info->lastchar - info->cursor;
+	el_cursor (editline, from_cursor_until_end);
+	el_insertstr (editline, "\n");
+	input_el_redisplay (self);
+	el_wdeletestr (editline, 1);
+	el_set (editline, EL_REFRESH);
+	input_el_hide (&self->super);
+
+	for (size_t i = 0; i < v->len; i++)
+		printf ("%s\n", v->vector[i]);
+
+	input_el_show (&self->super);
+	el_cursor (editline, -from_cursor_until_end);
+}
+
+static void
+input_el_insert_common_prefix (EditLine *editline, const struct strv *v)
+{
+	char *p[v->len]; memcpy (p, v->vector, sizeof p);
+	mbstate_t state[v->len]; memset (state, 0, sizeof state);
+	wchar_t want[2] = {}; size_t len;
+	while ((len = mbrtowc (&want[0], p[0], strlen (p[0]), &state[0])) > 0)
+	{
+		p[0] += len;
+		for (size_t i = 1; i < v->len; i++)
+		{
+			wchar_t found = 0;
+			if ((len = mbrtowc (&found, p[i], strlen (p[i]), &state[i])) <= 0
+			 || found != want[0])
+				return;
+			p[i] += len;
+		}
+		el_winsertstr (editline, want);
+	}
+}
+
+static unsigned char
+input_el_on_complete (EditLine *editline, int key)
+{
+	(void) key;
+
+	struct input_el *self;
+	el_get (editline, EL_CLIENTDATA, &self);
+
+	// First prepare what Readline would have normally done for us...
+	const LineInfo *info_mb = el_line (editline);
+	int len = info_mb->lastchar - info_mb->buffer;
+	int point = info_mb->cursor - info_mb->buffer;
+	char *word = xstrndup (info_mb->buffer, len);
+
+	int start = point;
+	while (start && !isspace_ascii (word[start - 1]))
+		start--;
+
+	// Only complete the first word, when we're at the end of it
+	if (start != 0
+	 || (word[point] && !isspace_ascii (word[point]))
+	 || (point && isspace_ascii (word[point - 1])))
+	{
+		free (word);
+		return CC_REFRESH_BEEP;
+	}
+
+	word[point] = '\0';
+	int word_len = mbstowcs (NULL, word, 0);
+	struct strv v = input_el_collect_candidates (self, word);
+	free (word);
+	if (!v.len)
+	{
+		strv_free (&v);
+		return CC_REFRESH_BEEP;
+	}
+
+	// Remove the original word and replace it with the best (sub)match
+	el_wdeletestr (editline, word_len);
+	if (v.len == 1)
+	{
+		el_insertstr (editline, v.vector[0]);
+		el_insertstr (editline, " ");
+		strv_free (&v);
+		return CC_REFRESH;
+	}
+
+	input_el_insert_common_prefix (editline, &v);
+	input_el_print_candidates (self, &v);
+	strv_free (&v);
+	return CC_REFRESH_BEEP;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
 static bool
 input_el_load_history (struct input *input, const char *filename,
 	struct error **e)
@@ -852,8 +1006,7 @@ input_el_on_tty_readable (struct input *input)
 		self->prompt_shown = 0;
 
 		self->super.on_input (self->entered_line, self->super.user_data);
-		free (self->entered_line);
-		self->entered_line = NULL;
+		cstr_set (&self->entered_line, NULL);
 
 		// Forbid editline from trying to erase the old prompt (or worse)
 		// and let it redisplay the prompt in its clean state
@@ -929,14 +1082,16 @@ static struct app_context
 
 	struct backend *backend;            ///< Our current backend
 	char *editor_filename;              ///< File for input line editor
+	struct str_map methods;             ///< Methods detected via OpenRPC
 
 	struct config config;               ///< Program configuration
 	enum color_mode color_mode;         ///< Colour output mode
-	bool pretty_print;                  ///< Whether to pretty print
+	bool compact;                       ///< Whether to not pretty print
 	bool verbose;                       ///< Print requests
 	bool trust_all;                     ///< Don't verify peer certificates
+	bool openrpc;                       ///< OpenRPC method name completion
 
-	bool auto_id;                       ///< Use automatically generated ID's
+	bool null_as_id;                    ///< JSON null is used as an ID
 	int64_t next_id;                    ///< Next autogenerated ID
 
 	iconv_t term_to_utf8;               ///< Terminal encoding to UTF-8
@@ -1237,10 +1392,9 @@ on_config_attribute_change (struct config_item *item)
 	ssize_t id = attr_by_name (item->schema->name);
 	if (id != -1)
 	{
-		free (ctx->attrs[id]);
-		ctx->attrs[id] = xstrdup (item->type == CONFIG_ITEM_NULL
+		cstr_set (&ctx->attrs[id], xstrdup (item->type == CONFIG_ITEM_NULL
 			? ctx->attrs_defaults[id]
-			: item->value.string.str);
+			: item->value.string.str));
 	}
 }
 
@@ -1683,7 +1837,7 @@ backend_ws_establish_connection (struct ws_context *self,
 		else
 			real_host = buf;
 
-		if (self->ctx->verbose)
+		if (g_debug_mode)
 		{
 			char *address = format_host_port_pair (real_host, port);
 			print_status ("connecting to %s...", address);
@@ -2716,6 +2870,7 @@ static void
 resume_terminal (struct app_context *ctx)
 {
 	ctx->input->vtable->prepare (ctx->input, true);
+	ctx->input->vtable->on_terminal_resized (ctx->input);
 	ev_io_start (EV_DEFAULT_ &ctx->tty_watcher);
 	ctx->input->vtable->show (ctx->input);
 }
@@ -2845,7 +3000,7 @@ process_response (struct app_context *ctx, const json_t *id, struct str *buf,
 	if (result)
 	{
 		int flags = JSON_ENCODE_ANY;
-		if (ctx->pretty_print)
+		if (!ctx->compact)
 			flags |= JSON_INDENT (2);
 
 		char *utf8 = json_dumps (result, flags);
@@ -2870,6 +3025,82 @@ fail:
 	return success;
 }
 
+static void
+maybe_print_verbose (struct app_context *ctx, intptr_t attribute,
+	char *utf8, size_t len)
+{
+	if (!ctx->verbose)
+		return;
+
+	char *term = iconv_xstrdup (ctx->term_from_utf8, utf8, len, NULL);
+	if (!term)
+	{
+		print_error ("%s: %s", "verbose", "character conversion failed");
+		return;
+	}
+
+	ctx->input->vtable->hide (ctx->input);
+
+	print_attributed (ctx, stdout, attribute, "%s", term);
+	fputs ("\n", stdout);
+	free (term);
+
+	ctx->input->vtable->show (ctx->input);
+}
+
+static struct error *
+json_rpc_call_raw (struct app_context *ctx,
+	const char *method, json_t *id, json_t *params, struct str *buf)
+{
+	json_t *request = json_object ();
+	json_object_set_new (request, "jsonrpc", json_string ("2.0"));
+	json_object_set_new (request, "method",  json_string (method));
+
+	if (id)      json_object_set (request, "id",     id);
+	if (params)  json_object_set (request, "params", params);
+
+	char *req_utf8 = json_dumps (request, 0);
+	json_decref (request);
+
+	maybe_print_verbose (ctx, ATTR_OUTGOING, req_utf8, -1);
+
+	struct error *error = NULL;
+	ctx->backend->vtable->make_call (ctx->backend, req_utf8,
+		id != NULL /* expect_content */, buf, &error);
+	free (req_utf8);
+
+	if (error)
+		return error;
+
+	maybe_print_verbose (ctx, ATTR_INCOMING, buf->str, buf->len + 1);
+	return NULL;
+}
+
+static void
+make_json_rpc_call (struct app_context *ctx,
+	const char *method, json_t *id, json_t *params, const char *pipeline)
+{
+	struct str buf = str_make ();
+	struct error *e = json_rpc_call_raw (ctx, method, id, params, &buf);
+	if (e)
+	{
+		print_error ("%s", e->message);
+		error_free (e);
+	}
+	else if (!process_response (ctx, id, &buf, pipeline))
+	{
+		char *s = iconv_xstrdup (ctx->term_from_utf8,
+			buf.str, buf.len + 1 /* null byte */, NULL);
+		if (!s)
+			print_error ("character conversion failed for `%s'",
+				"raw response data");
+		else if (!ctx->verbose /* already printed */)
+			printf ("%s: %s\n", "raw response data", s);
+		free (s);
+	}
+	str_free (&buf);
+}
+
 static bool
 is_valid_json_rpc_id (json_t *v)
 {
@@ -2883,73 +3114,6 @@ is_valid_json_rpc_params (json_t *v)
 	return json_is_array (v) || json_is_object (v);
 }
 
-static void
-make_json_rpc_call (struct app_context *ctx,
-	const char *method, json_t *id, json_t *params, const char *pipeline)
-{
-	json_t *request = json_object ();
-	json_object_set_new (request, "jsonrpc", json_string ("2.0"));
-	json_object_set_new (request, "method",  json_string (method));
-
-	if (id)      json_object_set (request, "id",     id);
-	if (params)  json_object_set (request, "params", params);
-
-	char *req_utf8 = json_dumps (request, 0);
-	if (ctx->verbose)
-	{
-		char *req_term = iconv_xstrdup
-			(ctx->term_from_utf8, req_utf8, -1, NULL);
-		if (!req_term)
-			print_error ("%s: %s", "verbose", "character conversion failed");
-		else
-		{
-			print_attributed (ctx, stdout, ATTR_OUTGOING, "%s", req_term);
-			fputs ("\n", stdout);
-		}
-		free (req_term);
-	}
-
-	struct str buf = str_make ();
-	struct error *e = NULL;
-	if (!ctx->backend->vtable->make_call
-		(ctx->backend, req_utf8, id != NULL, &buf, &e))
-	{
-		print_error ("%s", e->message);
-		error_free (e);
-		goto fail;
-	}
-
-	if (ctx->verbose)
-	{
-		char *buf_term =
-			iconv_xstrdup (ctx->term_from_utf8, buf.str, buf.len, NULL);
-		if (!buf_term)
-			print_error ("%s: %s", "verbose", "character conversion failed");
-		else
-		{
-			print_attributed (ctx, stdout, ATTR_INCOMING, "%s", buf_term);
-			fputs ("\n", stdout);
-		}
-		free (buf_term);
-	}
-
-	if (!process_response (ctx, id, &buf, pipeline))
-	{
-		char *s = iconv_xstrdup (ctx->term_from_utf8,
-			buf.str, buf.len + 1 /* null byte */, NULL);
-		if (!s)
-			print_error ("character conversion failed for `%s'",
-				"raw response data");
-		else if (!ctx->verbose /* already printed */)
-			printf ("%s: %s\n", "raw response data", s);
-		free (s);
-	}
-fail:
-	str_free (&buf);
-	free (req_utf8);
-	json_decref (request);
-}
-
 static void
 process_input (char *user_input, void *user_data)
 {
@@ -3041,9 +3205,16 @@ process_input (char *user_input, void *user_data)
 		*target = json_incref (args[i]);
 	}
 
-	if (!id && ctx->auto_id)
+	if (!id)
 		id = json_integer (ctx->next_id++);
 
+	// Use nulls to send notifications, unless a special switch is used
+	if (!ctx->null_as_id && json_is_null (id))
+	{
+		json_decref (id);
+		id = NULL;
+	}
+
 	make_json_rpc_call (ctx, method, id, params, pipeline);
 
 fail_parse:
@@ -3058,56 +3229,81 @@ fail:
 	free (input);
 }
 
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+// --- OpenRPC information extraction ------------------------------------------
+
+static void
+parse_rpc_discover (struct app_context *ctx, struct str *buf, struct error **e)
+{
+	// Just optimistically punch through, I don't have time for this shit
+	json_error_t error;
+	json_t *response = NULL, *result = NULL, *value = NULL;
+	if (!(response = json_loadb (buf->str, buf->len, 0, &error)))
+		error_set (e, "parse failure: %s", error.text);
+	else if (!(result = json_object_get (response, "result"))
+		|| !(result = json_object_get (result, "methods")))
+		error_set (e, "unsupported");
+	else
+	{
+		const char *name = NULL;
+		for (size_t i = 0; (value = json_array_get (result, i)); i++)
+			if ((value = json_object_get (value, "name"))
+			 && (name = json_string_value (value)))
+				str_map_set (&ctx->methods, name, (void *) 1);
+	}
+	json_decref (response);
+}
+
+static void
+init_openrpc (struct app_context *ctx)
+{
+	if (!ctx->openrpc)
+		return;
+
+	json_t *id = json_integer (ctx->next_id++);
+	struct str buf = str_make ();
+	struct error *error;
+	if (!(error = json_rpc_call_raw (ctx, "rpc.discover", id, NULL, &buf)))
+		parse_rpc_discover (ctx, &buf, &error);
+	json_decref (id);
+
+	if (error)
+	{
+		print_error ("OpenRPC: %s", error->message);
+		error_free (error);
+	}
+	str_free (&buf);
+}
+
+static char *
+complete_method_name (const char *text, int state)
+{
+	static struct str_map_iter iter;
+	if (!state)
+		iter = str_map_iter_make (&g_ctx.methods);
+
+	char *input;
+	size_t len;
+	if (!(input = iconv_xstrdup (g_ctx.term_to_utf8, (char *) text, -1, &len)))
+	{
+		print_error ("character conversion failed for `%s'", "user input");
+		return NULL;
+	}
+
+	char *match = NULL;
+	while (str_map_iter_next (&iter)
+		&& (strncasecmp_ascii (input, iter.link->key, len - 1 /* XXX */)
+			|| !(match = iconv_xstrdup (g_ctx.term_from_utf8,
+				iter.link->key, iter.link->key_length + 1, NULL))))
+		;
+	free (input);
+	return match;
+}
+
+// --- Main program ------------------------------------------------------------
 
 // The ability to use an external editor on the input line has been shamelessly
 // copypasted from degesch with minor changes only.
 
-/// This differs from the non-unique version in that we expect the filename
-/// to be something like a pattern for mkstemp(), so the resulting path can
-/// reside in a system-wide directory with no risk of a conflict.
-static char *
-resolve_relative_runtime_unique_filename (const char *filename)
-{
-	struct str path = str_make ();
-
-	const char *runtime_dir = getenv ("XDG_RUNTIME_DIR");
-	const char *tmpdir = getenv ("TMPDIR");
-	if (runtime_dir && *runtime_dir == '/')
-		str_append (&path, runtime_dir);
-	else if (tmpdir && *tmpdir == '/')
-		str_append (&path, tmpdir);
-	else
-		str_append (&path, "/tmp");
-	str_append_printf (&path, "/%s/%s", PROGRAM_NAME, filename);
-
-	// Try to create the file's ancestors;
-	// typically the user will want to immediately create a file in there
-	const char *last_slash = strrchr (path.str, '/');
-	if (last_slash && last_slash != path.str)
-	{
-		char *copy = xstrndup (path.str, last_slash - path.str);
-		(void) mkdir_with_parents (copy, NULL);
-		free (copy);
-	}
-	return str_steal (&path);
-}
-
-static bool
-xwrite (int fd, const char *data, size_t len, struct error **e)
-{
-	size_t written = 0;
-	while (written < len)
-	{
-		ssize_t res = write (fd, data + written, len - written);
-		if (res >= 0)
-			written += res;
-		else if (errno != EINTR)
-			FAIL ("%s", strerror (errno));
-	}
-	return true;
-}
-
 static bool
 dump_line_to_file (const char *line, char *template, struct error **e)
 {
@@ -3127,7 +3323,7 @@ static char *
 try_dump_line_to_file (const char *line)
 {
 	char *template = resolve_filename
-		("input.XXXXXX", resolve_relative_runtime_unique_filename);
+		("input.XXXXXX", resolve_relative_runtime_template);
 
 	struct error *e = NULL;
 	if (dump_line_to_file (line, template, &e))
@@ -3252,8 +3448,7 @@ on_child (EV_P_ ev_child *handle, int revents)
 	else
 		process_edited_input (ctx);
 
-	free (ctx->editor_filename);
-	ctx->editor_filename = NULL;
+	cstr_set (&ctx->editor_filename, NULL);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -3338,24 +3533,26 @@ parse_program_arguments (struct app_context *ctx, int argc, char **argv,
 {
 	static const struct opt opts[] =
 	{
-		{ 'd', "debug", NULL, 0, "run in debug mode" },
-		{ 'h', "help", NULL, 0, "display this help and exit" },
-		{ 'V', "version", NULL, 0, "output version information and exit" },
-		{ 'a', "auto-id", NULL, 0, "automatic `id' fields" },
-		{ 'o', "origin", "O", 0, "set the HTTP Origin header" },
-		{ 'p', "pretty", NULL, 0, "pretty-print the responses" },
-		{ 't', "trust-all", NULL, 0, "don't care about SSL/TLS certificates" },
-		{ 'v', "verbose", NULL, 0, "print the request before sending" },
-		{ 'c', "color", "WHEN", OPT_LONG_ONLY,
+		{ 'c', "compact-output", NULL, 0, "do not pretty-print responses" },
+		{ 'C', "color", "WHEN", OPT_LONG_ONLY,
 		  "colorize output: never, always, or auto" },
+		{ 'n', "null-as-id", NULL, 0, "JSON null is used as an `id'" },
+		{ 'o', "origin", "O", 0, "set the HTTP Origin header" },
+		// So far you have to explicitly enable this rather than disable
+		{ 'O', "openrpc", NULL, 0, "method name completion using OpenRPC" },
+		{ 't', "trust-all", NULL, 0, "don't care about SSL/TLS certificates" },
+		{ 'v', "verbose", NULL, 0, "print raw requests and responses" },
 		{ 'w', "write-default-cfg", "FILENAME",
 		  OPT_OPTIONAL_ARG | OPT_LONG_ONLY,
 		  "write a default configuration file and exit" },
+		{ 'd', "debug", NULL, 0, "run in debug mode" },
+		{ 'h', "help", NULL, 0, "display this help message and exit" },
+		{ 'V', "version", NULL, 0, "output version information and exit" },
 		{ 0, NULL, NULL, 0, NULL }
 	};
 
 	struct opt_handler oh = opt_handler_make (argc, argv, opts,
-		"ENDPOINT", "Simple JSON-RPC shell.");
+		"ENDPOINT", "A simple JSON-RPC 2.0 shell.");
 
 	int c;
 	while ((c = opt_handler_get (&oh)) != -1)
@@ -3372,12 +3569,13 @@ parse_program_arguments (struct app_context *ctx, int argc, char **argv,
 		exit (EXIT_SUCCESS);
 
 	case 'o': *origin = optarg;         break;
-	case 'a': ctx->auto_id      = true; break;
-	case 'p': ctx->pretty_print = true; break;
+	case 'O': ctx->openrpc      = true; break;
+	case 'n': ctx->null_as_id   = true; break;
+	case 'c': ctx->compact      = true; break;
 	case 't': ctx->trust_all    = true; break;
 	case 'v': ctx->verbose      = true; break;
 
-	case 'c':
+	case 'C':
 		if      (!strcasecmp (optarg, "never"))
 			ctx->color_mode = COLOR_NEVER;
 		else if (!strcasecmp (optarg, "always"))
@@ -3428,7 +3626,9 @@ main (int argc, char *argv[])
 	g_ctx.input->user_data = &g_ctx;
 	g_ctx.input->on_input = process_input;
 	g_ctx.input->on_run_editor = run_editor;
+	g_ctx.input->complete_start_word = complete_method_name;
 
+	g_ctx.methods = str_map_make (NULL);
 	init_colors (&g_ctx);
 	load_configuration (&g_ctx);
 
@@ -3508,6 +3708,7 @@ main (int argc, char *argv[])
 	g_ctx.input->vtable->start (g_ctx.input, PROGRAM_NAME);
 
 	ev_set_userdata (EV_DEFAULT_ &g_ctx);
+	init_openrpc (&g_ctx);
 	ev_run (EV_DEFAULT_ 0);
 
 	// User has terminated the program, let's save the history and clean up
@@ -3530,6 +3731,7 @@ main (int argc, char *argv[])
 
 	iconv_close (g_ctx.term_from_utf8);
 	iconv_close (g_ctx.term_to_utf8);
+	str_map_free (&g_ctx.methods);
 	config_free (&g_ctx.config);
 	free_terminal ();
 	ev_loop_destroy (EV_DEFAULT);

json-rpc-test-server.c

@@ -329,6 +329,7 @@ fcgi_muxer_on_get_values
 	nv_parser.output = &values;
 
 	fcgi_nv_parser_push (&nv_parser, parser->content.str, parser->content.len);
+	fcgi_nv_parser_free (&nv_parser);
 	const char *key = NULL;
 
 	// No real-world servers seem to actually use multiplexing
@@ -1013,7 +1014,7 @@ static int
 ws_handler_on_url (http_parser *parser, const char *at, size_t len)
 {
 	struct ws_handler *self = parser->data;
-	str_append_data (&self->value, at, len);
+	str_append_data (&self->url, at, len);
 	return 0;
 }