vis: add an interactive mode to vis_pipe{,_collect}(...)

Previously the interactive mode was implicitly enabled by passing
an invalid range. However for some use cases (e.g. completion) we
need to be able to pipe a given text range to an external process
without also redirecting stderr (which is used to draw the slmenu
interface on top of vis).

5 files changed, 19 insertions, 17 deletions

diff --git a/register.c b/register.c
index 6f8caa5..d221fe2 100644
--- a/register.c
+++ b/register.c
@@ -33,7 +33,7 @@ const char *register_get(Vis *vis, Register *reg, size_t *len) {
 		buffer_init(&buferr);
 		buffer_clear(&reg->buf);
 
-		int status = vis_pipe(vis, &(Filerange){ .start = 0, .end = 0 },
+		int status = vis_pipe(vis, &(Filerange){ .start = 0, .end = 0 }, false,
 			(const char*[]){ VIS_CLIPBOARD, "--paste", NULL },
 			&reg->buf, read_buffer, &buferr, read_buffer);
 
@@ -74,7 +74,7 @@ bool register_put_range(Vis *vis, Register *reg, Text *txt, Filerange *range) {
 		Buffer buferr;
 		buffer_init(&buferr);
 
-		int status = vis_pipe(vis, range, (const char*[]){ VIS_CLIPBOARD, "--copy", NULL },
+		int status = vis_pipe(vis, range, false, (const char*[]){ VIS_CLIPBOARD, "--copy", NULL },
 			NULL, NULL, &buferr, read_buffer);
 
 		if (status != 0)
diff --git a/sam.c b/sam.c
index 1f5e816..717b380 100644
--- a/sam.c
+++ b/sam.c
@@ -1150,7 +1150,7 @@ static bool cmd_filter(Vis *vis, Win *win, Command *cmd, const char *argv[], Cur
 	Buffer buferr;
 	buffer_init(&buferr);
 
-	int status = vis_pipe(vis, range, &argv[1], &filter, read_text, &buferr, read_buffer);
+	int status = vis_pipe(vis, range, false, &argv[1], &filter, read_text, &buferr, read_buffer);
 
 	if (status == 0) {
 		text_delete_range(txt, range);
@@ -1198,7 +1198,7 @@ static bool cmd_pipeout(Vis *vis, Win *win, Command *cmd, const char *argv[], Cu
 	Buffer buferr;
 	buffer_init(&buferr);
 
-	int status = vis_pipe(vis, range, (const char*[]){ argv[1], NULL }, NULL, NULL, &buferr, read_buffer);
+	int status = vis_pipe(vis, range, false, (const char*[]){ argv[1], NULL }, NULL, NULL, &buferr, read_buffer);
 
 	if (status == 0 && cur)
 		view_cursors_to(cur, range->start);
diff --git a/vis-cmds.c b/vis-cmds.c
index 92ba417..ea20e9a 100644
--- a/vis-cmds.c
+++ b/vis-cmds.c
@@ -331,7 +331,7 @@ static const char *file_open_dialog(Vis *vis, const char *pattern) {
 		return NULL;
 
 	Filerange empty = text_range_empty();
-	int status = vis_pipe(vis, &empty, (const char*[]){ buffer_content0(&bufcmd), NULL },
+	int status = vis_pipe(vis, &empty, true, (const char*[]){ buffer_content0(&bufcmd), NULL },
 		&bufout, read_buffer, &buferr, read_buffer);
 
 	if (status == 0)
diff --git a/vis.c b/vis.c
index e367291..f35c50b 100644
--- a/vis.c
+++ b/vis.c
@@ -1161,20 +1161,18 @@ Regex *vis_regex(Vis *vis, const char *pattern) {
 	return regex;
 }
 
-int vis_pipe(Vis *vis, Filerange *range, const char *argv[],
+int vis_pipe(Vis *vis, Filerange *range, bool interactive, 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)) {
 
 	/* if an invalid range was given, stdin (i.e. key board input) is passed
 	 * through the external command. */
 	Text *text = vis->win->file->text;
-	View *view = vis->win->view;
 	int pin[2], pout[2], perr[2], status = -1;
-	bool interactive = !text_range_valid(range);
-	size_t pos = view_cursor_get(view);
-	Filerange rout = *range;
-	if (interactive)
-		rout = (Filerange){ .start = pos, .end = pos };
+	bool valid_range = text_range_valid(range);
+	if (!valid_range)
+		interactive = true;
+	Filerange rout = valid_range ? *range : text_range_new(0, 0);
 
 	if (pipe(pin) == -1)
 		return -1;
@@ -1205,7 +1203,7 @@ int vis_pipe(Vis *vis, Filerange *range, const char *argv[],
 		vis_info_show(vis, "fork failure: %s", strerror(errno));
 		return -1;
 	} else if (pid == 0) { /* child i.e filter */
-		if (!interactive)
+		if (!interactive || valid_range)
 			dup2(pin[0], STDIN_FILENO);
 		close(pin[0]);
 		close(pin[1]);
@@ -1330,11 +1328,11 @@ static ssize_t read_buffer(void *context, char *data, size_t len) {
 	return len;
 }
 
-int vis_pipe_collect(Vis *vis, Filerange *range, const char *argv[], char **out, char **err) {
+int vis_pipe_collect(Vis *vis, Filerange *range, bool interactive, const char *argv[], char **out, char **err) {
 	Buffer bufout, buferr;
 	buffer_init(&bufout);
 	buffer_init(&buferr);
-	int status = vis_pipe(vis, range, argv, &bufout, read_buffer, &buferr, read_buffer);
+	int status = vis_pipe(vis, range, interactive, argv, &bufout, read_buffer, &buferr, read_buffer);
 	buffer_terminate(&bufout);
 	buffer_terminate(&buferr);
 	if (out)
diff --git a/vis.h b/vis.h
index 0b819a9..e4ffa06 100644
--- a/vis.h
+++ b/vis.h
@@ -410,6 +410,10 @@ bool vis_prompt_cmd(Vis*, const char *cmd);
 
 /* pipe a given file range to an external process
  *
+ * in interactive mode stdin and stderr are not redirected, hence they
+ * can be used to read keyboard input and draw a user interface on top
+ * of vis. Attempting to pipe an invalid range enables interactive mode.
+ *
  * if argv contains only one non-NULL element the command is executed using
  * /bin/sh -c (i.e. argument expansion is performed by the shell). In contrast
  * if argv contains more than one non-NULL element execvp(argv[0], argv); will
@@ -418,14 +422,14 @@ bool vis_prompt_cmd(Vis*, const char *cmd);
  * if read_std{out,err} are non-NULL they will be called when output from
  * the forked process is available.
  */
-int vis_pipe(Vis *vis, Filerange *range, const char *argv[],
+int vis_pipe(Vis *vis, Filerange *range, bool interactive, 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));
 
 /* pipe a range to an external application, return its exit status and store
  * everything that is written to stdout/stderr in the gitven char pointers
  * which have to be free(3)-ed by the caller */
-int vis_pipe_collect(Vis *vis, Filerange *range, const char *argv[], char **out, char **err);
+int vis_pipe_collect(Vis *vis, Filerange *range, bool interactive, const char *argv[], char **out, char **err);
 
 /* given the start of a key, returns a pointer to the start of the one immediately
  * following as will be processed by the input system. skips over special keys