supporting piping a buffer to an external process

lua/plugins/complete-word.lua

@@ -24,8 +24,7 @@ vis:map(vis.modes.INSERT, "<C-n>", function()
 	if #candidates == 1 and candidates[1] == "\n" then return end
 	candidates = table.concat(candidates, "\n")
 
-	local cmd = "printf '" .. candidates .. "' | sort -u | vis-menu"
-	local status, out, err = vis:pipe(cmd)
+	local status, out, err = vis:pipe(candidates, "sort -u | vis-menu")
 	if status ~= 0 or not out then
 		if err then vis:info(err) end
 		return

test/lua/pipe.in

@@ -0,0 +1 @@
+foo

test/lua/pipe.lua

@@ -0,0 +1,86 @@
+require 'busted.runner'()
+
+local file = vis.win.file
+
+describe("vis.pipe", function()
+
+	local FULLSCREEN = true
+
+	it("vis.pipe no input", function()
+		vis:pipe("cat > f")
+		local f = io.open("f", "r")
+		assert.truthy(f)
+		assert.are.equal("", f:read("*a"))
+		f:close()
+		os.remove("f")
+	end)
+
+	it("vis.pipe no input fullscreen", function()
+		vis:pipe("cat > f", FULLSCREEN)
+		local f = io.open("f", "r")
+		assert.truthy(f)
+		assert.are.equal("", f:read("*a"))
+		f:close()
+		os.remove("f")
+	end)
+
+	it("vis.pipe buffer", function()
+		vis:pipe("foo", "cat > f")
+		local f = io.open("f", "r")
+		assert.truthy(f)
+		assert.are.equal(f:read("*a"), "foo")
+		f:close()
+		os.remove("f")
+	end)
+
+	it("vis.pipe buffer fullscreen", function()
+		vis:pipe("foo", "cat > f", FULLSCREEN)
+		local f = io.open("f", "r")
+		assert.truthy(f)
+		assert.are.equal(f:read("*a"), "foo")
+		f:close()
+		os.remove("f")
+	end)
+
+	it("vis.pipe range", function()
+		vis:pipe(file, {start=0, finish=3}, "cat > f")
+		local f = io.open("f", "r")
+		assert.truthy(f)
+		assert.are.equal(f:read("*a"), "foo")
+		f:close()
+		os.remove("f")
+	end)
+
+	it("vis.pipe range fullscreen", function()
+		vis:pipe(file, {start=0, finish=3}, "cat > f", FULLSCREEN)
+		local f = io.open("f", "r")
+		assert.truthy(f)
+		assert.are.equal(f:read("*a"), "foo")
+		f:close()
+		os.remove("f")
+	end)
+
+	it("vis.pipe explicit nil text", function()
+		assert.has_error(function() vis:pipe(nil, "true") end)
+	end)
+
+	it("vis.pipe explicit nil text fullscreen", function()
+		assert.has_error(function() vis:pipe(nil, "true", FULLSCREEN) end)
+	end)
+
+	it("vis.pipe explicit nil file", function()
+		assert.has_error(function() vis:pipe(nil, {start=0, finish=0}, "true") end)
+	end)
+
+	it("vis.pipe explicit nil file fullscreen", function()
+		assert.has_error(function() vis:pipe(nil, {start=0, finish=0}, "true", FULLSCREEN) end)
+	end)
+
+	it("vis.pipe wrong argument order file, range, cmd", function()
+		assert.has_error(function() vis:pipe({start=0, finish=0}, vis.win.file, "true") end)
+	end)
+
+	it("vis.pipe wrong argument order fullscreen, cmd", function()
+		assert.has_error(function() vis:pipe(FULLSCREEN, "true") end)
+	end)
+end)

text-io.c

@@ -182,7 +182,7 @@ Text *text_load_method(const char *filename, enum TextLoadMethod method) {
 	return text_loadat_method(AT_FDCWD, filename, method);
 }
 
-static ssize_t write_all(int fd, const char *buf, size_t count) {
+ssize_t write_all(int fd, const char *buf, size_t count) {
 	size_t rem = count;
 	while (rem > 0) {
 		ssize_t written = write(fd, buf, rem > INT_MAX ? INT_MAX : rem);

text.h

@@ -413,6 +413,12 @@ ssize_t text_write_range(const Text*, const Filerange*, int fd);
  * this text instance.
  */
 bool text_mmaped(const Text*, const char *ptr);
+
+/**
+ * Write complete buffer to file descriptor.
+ * @return The number of bytes written or ``-1`` in case of an error.
+ */
+ssize_t write_all(int fd, const char *buf, size_t count);
 /** @} */
 
 #endif

vis-lua.c

@@ -1234,25 +1234,53 @@ static int exit_func(lua_State *L) {
  * @treturn string stdout the data written to stdout
  * @treturn string stderr the data written to stderr
  */
+/***
+ * Pipe a string to external process and collect output.
+ *
+ * The editor core will be blocked while the external process is running.
+ *
+ * @function pipe
+ * @tparam string text the text written to the external command
+ * @tparam string command the command to execute
+ * @tparam[opt] bool fullscreen whether command is a fullscreen program (e.g. curses based)
+ * @treturn int code the exit status of the executed command
+ * @treturn string stdout the data written to stdout
+ * @treturn string stderr the data written to stderr
+ */
 static int pipe_func(lua_State *L) {
 	Vis *vis = obj_ref_check(L, 1, "vis");
 	int cmd_idx = 4;
 	char *out = NULL, *err = NULL;
+	const char *text = NULL;
 	File *file = vis->win ? vis->win->file : NULL;
 	Filerange range = text_range_new(0, 0);
-	if (lua_gettop(L) <= 3) {
+	if (lua_gettop(L) == 2) { // vis:pipe(cmd)
 		cmd_idx = 2;
-	} else if (!(lua_isnil(L, 2) && lua_isnil(L, 3))) {
+	} else if (lua_gettop(L) == 3) {
+		if (lua_isboolean(L, 3)) { // vis:pipe(cmd, fullscreen)
+			cmd_idx = 2;
+		} else { // vis:pipe(text, cmd)
+			text = luaL_checkstring(L, 2);
+			cmd_idx = 3;
+		}
+	} else if (lua_isboolean(L, 4)) { // vis:pipe(text, cmd, fullscreen)
+		text = luaL_checkstring(L, 2);
+		cmd_idx = 3;
+	} else if (!(lua_isnil(L, 2) && lua_isnil(L, 3))) { // vis:pipe(file, range, cmd, [fullscreen])
 		file = obj_ref_check(L, 2, VIS_LUA_TYPE_FILE);
 		range = getrange(L, 3);
 	}
 	const char *cmd = luaL_checkstring(L, cmd_idx);
 	bool fullscreen = lua_isboolean(L, cmd_idx + 1) && lua_toboolean(L, cmd_idx + 1);
 
-	if (!file)
+	if (!text && !file)
 		return luaL_error(L, "vis:pipe(cmd = '%s'): win not open, file can't be nil", cmd);
 
-	int status = vis_pipe_collect(vis, file, &range, (const char*[]){ cmd, NULL }, &out, &err, fullscreen);
+	int status;
+	if (text)
+		status = vis_pipe_buf_collect(vis, text, (const char*[]){ cmd, NULL }, &out, &err, fullscreen);
+	else
+		status = vis_pipe_collect(vis, file, &range, (const char*[]){ cmd, NULL }, &out, &err, fullscreen);
 	lua_pushinteger(L, status);
 	if (out)
 		lua_pushstring(L, out);

vis.c

@@ -1593,17 +1593,17 @@ Regex *vis_regex(Vis *vis, const char *pattern) {
 	return regex;
 }
 
-int vis_pipe(Vis *vis, File *file, Filerange *range, const char *argv[],
+static int _vis_pipe(Vis *vis, File *file, Filerange *range, const char* buf, const char *argv[],
 	void *stdout_context, ssize_t (*read_stdout)(void *stdout_context, char *data, size_t len),
 	void *stderr_context, ssize_t (*read_stderr)(void *stderr_context, char *data, size_t len),
 	bool fullscreen) {
 
 	/* if an invalid range was given, stdin (i.e. key board input) is passed
 	 * through the external command. */
-	Text *text = file->text;
+	Text *text = file != NULL ? file->text : NULL;
 	int pin[2], pout[2], perr[2], status = -1;
-	bool interactive = !text_range_valid(range);
-	Filerange rout = interactive ? text_range_new(0, 0) : *range;
+	bool interactive = buf == NULL && (range == NULL || !text_range_valid(range));
+	Filerange rout = (interactive  || buf != NULL) ? text_range_new(0, 0) : *range;
 
 	if (pipe(pin) == -1)
 		return -1;
@@ -1654,7 +1654,7 @@ int vis_pipe(Vis *vis, File *file, Filerange *range, const char *argv[],
 			 * closed. Some programs behave differently when used
 			 * in a pipeline.
 			 */
-			if (text_range_size(range) == 0)
+			if (range && text_range_size(range) == 0)
 				dup2(null, STDIN_FILENO);
 			else
 				dup2(pin[0], STDIN_FILENO);
@@ -1688,7 +1688,7 @@ int vis_pipe(Vis *vis, File *file, Filerange *range, const char *argv[],
 		close(perr[1]);
 		close(null);
 
-		if (file->name) {
+		if (file != NULL && file->name) {
 			char *name = strrchr(file->name, '/');
 			setenv("vis_filepath", file->name, 1);
 			setenv("vis_filename", name ? name+1 : file->name, 1);
@@ -1737,20 +1737,36 @@ int vis_pipe(Vis *vis, File *file, Filerange *range, const char *argv[],
 		}
 
 		if (pin[1] != -1 && FD_ISSET(pin[1], &wfds)) {
+			ssize_t written = 0;
 			Filerange junk = rout;
-			if (junk.end > junk.start + PIPE_BUF)
-				junk.end = junk.start + PIPE_BUF;
-			ssize_t len = text_write_range(text, &junk, pin[1]);
-			if (len > 0) {
-				rout.start += len;
-				if (text_range_size(&rout) == 0) {
-					close(pin[1]);
-					pin[1] = -1;
+			if (text_range_size(&rout)) {
+				if (junk.end > junk.start + PIPE_BUF)
+					junk.end = junk.start + PIPE_BUF;
+				written = text_write_range(text, &junk, pin[1]);
+				if (written > 0) {
+					rout.start += written;
+					if (text_range_size(&rout) == 0) {
+						close(pin[1]);
+						pin[1] = -1;
+					}
 				}
-			} else {
+			} else if (buf != NULL) {
+				size_t len = strlen(buf);
+				if (len > 0) {
+					if (len > PIPE_BUF)
+						len = PIPE_BUF;
+
+					written = write_all(pin[1], buf, len);
+					if (written > 0) {
+						buf += written;
+					}
+				}
+			}
+
+			if (written <= 0) {
 				close(pin[1]);
 				pin[1] = -1;
-				if (len == -1)
+				if (written == -1)
 					vis_info_show(vis, "Error writing to external command");
 			}
 		}
@@ -1823,16 +1839,30 @@ int vis_pipe(Vis *vis, File *file, Filerange *range, const char *argv[],
 	return -1;
 }
 
+int vis_pipe(Vis *vis, File *file, Filerange *range, const char *argv[],
+	void *stdout_context, ssize_t (*read_stdout)(void *stdout_context, char *data, size_t len),
+	void *stderr_context, ssize_t (*read_stderr)(void *stderr_context, char *data, size_t len),
+	bool fullscreen) {
+	return _vis_pipe(vis, file, range, NULL, argv, stdout_context, read_stdout, stderr_context, read_stderr, fullscreen);
+}
+
+int vis_pipe_buf(Vis *vis, const char* buf, const char *argv[],
+	void *stdout_context, ssize_t (*read_stdout)(void *stdout_context, char *data, size_t len),
+	void *stderr_context, ssize_t (*read_stderr)(void *stderr_context, char *data, size_t len),
+	bool fullscreen) {
+	return _vis_pipe(vis, NULL, NULL, buf, argv, stdout_context, read_stdout, stderr_context, read_stderr, fullscreen);
+}
+
 static ssize_t read_buffer(void *context, char *data, size_t len) {
 	buffer_append(context, data, len);
 	return len;
 }
 
-int vis_pipe_collect(Vis *vis, File *file, Filerange *range, const char *argv[], char **out, char **err, bool fullscreen) {
+static int _vis_pipe_collect(Vis *vis, File *file, Filerange *range, const char* buf, const char *argv[], char **out, char **err, bool fullscreen) {
 	Buffer bufout, buferr;
 	buffer_init(&bufout);
 	buffer_init(&buferr);
-	int status = vis_pipe(vis, file, range, argv,
+	int status = _vis_pipe(vis, file, range, buf, argv,
 	                      &bufout, out ? read_buffer : NULL,
 	                      &buferr, err ? read_buffer : NULL,
 	                      fullscreen);
@@ -1847,6 +1877,14 @@ int vis_pipe_collect(Vis *vis, File *file, Filerange *range, const char *argv[],
 	return status;
 }
 
+int vis_pipe_collect(Vis *vis, File *file, Filerange *range, const char *argv[], char **out, char **err, bool fullscreen) {
+	return _vis_pipe_collect(vis, file, range, NULL, argv, out, err, fullscreen);
+}
+
+int vis_pipe_buf_collect(Vis *vis, const char* buf, const char *argv[], char **out, char **err, bool fullscreen) {
+	return _vis_pipe_collect(vis, NULL, NULL, buf, argv, out, err, fullscreen);
+}
+
 bool vis_cmd(Vis *vis, const char *cmdline) {
 	if (!cmdline)
 		return true;

vis.h

@@ -882,6 +882,20 @@ int vis_pipe(Vis*, File*, Filerange*, const char *argv[],
  */
 int vis_pipe_collect(Vis*, File*, Filerange*, const char *argv[], char **out, char **err, bool fullscreen);
 
+/**
+ * Pipe a buffer to an external process, return its exit status and capture
+ * everything that is written to stdout/stderr.
+ * @param argv Argument list, must be ``NULL`` terminated.
+ * @param out Data written to ``stdout``, will be ``NUL`` terminated.
+ * @param err Data written to ``stderr``, will be ``NUL`` terminated.
+ * @param fullscreen Whether the external process is a fullscreen program (e.g. curses based)
+ * @rst
+ * .. warning:: The pointers stored in ``out`` and ``err`` need to be `free(3)`-ed
+ *              by the caller.
+ * @endrst
+ */
+int vis_pipe_buf_collect(Vis*, const char*, const char *argv[], char **out, char **err, bool fullscreen);
+
 /**
  * @}
  * @defgroup vis_keys