vis: generalize special stdin handling

In preparation to move argument parsing code out of vis.c.

5 files changed, 21 insertions, 8 deletions

diff --git a/sam.c b/sam.c
index 926b056..328cf3d 100644
--- a/sam.c
+++ b/sam.c
@@ -1157,7 +1157,7 @@ static bool cmd_write(Vis *vis, Win *win, Command *cmd, const char *argv[], Curs
 	if (!argv[1])
 		argv[1] = file->name ? strdup(file->name) : NULL;
 	if (!argv[1]) {
-		if (!file->is_stdin) {
+		if (file->fd == -1) {
 			vis_info_show(vis, "Filename expected");
 			return false;
 		}
@@ -1171,7 +1171,7 @@ static bool cmd_write(Vis *vis, Win *win, Command *cmd, const char *argv[], Curs
 			bool all = !text_range_valid(&range);
 			if (all)
 				range = text_range_new(0, text_size(text));
-			ssize_t written = text_write_range(text, &range, STDOUT_FILENO);
+			ssize_t written = text_write_range(text, &range, file->fd);
 			if (written == -1 || (size_t)written != text_range_size(&range)) {
 				vis_info_show(vis, "Can not write to stdout");
 				return false;
diff --git a/vis-cmds.c b/vis-cmds.c
index 582f1a8..b3c1de8 100644
--- a/vis-cmds.c
+++ b/vis-cmds.c
@@ -431,7 +431,7 @@ static bool cmd_wq(Vis *vis, Win *win, Command *cmd, const char *argv[], Cursor
 	if (!win)
 		return false;
 	File *file = win->file;
-	bool unmodified = !file->is_stdin && !file->name && !text_modified(file->text);
+	bool unmodified = file->fd == -1 && !file->name && !text_modified(file->text);
 	if (unmodified || cmd_write(vis, win, cmd, argv, cur, range))
 		return cmd_quit(vis, win, cmd, argv, cur, range);
 	return false;
diff --git a/vis-core.h b/vis-core.h
index e16d23a..05ddca8 100644
--- a/vis-core.h
+++ b/vis-core.h
@@ -110,7 +110,7 @@ struct File { /* shared state among windows displaying the same file */
 	Text *text;                      /* data structure holding the file content */
 	const char *name;                /* file name used when loading/saving */
 	volatile sig_atomic_t truncated; /* whether the underlying memory mapped region became invalid (SIGBUS) */
-	bool is_stdin;                   /* whether file content was read from stdin */
+	int fd;                          /* output file descriptor associated with this file or -1 if loaded by file name */
 	bool internal;                   /* whether it is an internal file (e.g. used for the prompt) */
 	struct stat stat;                /* filesystem information when loaded/saved, used to detect changes outside the editor */
 	int refcount;                    /* how many windows are displaying this file? (always >= 1) */
diff --git a/vis.c b/vis.c
index 6782a8e..600a636 100644
--- a/vis.c
+++ b/vis.c
@@ -60,6 +60,7 @@ static File *file_new_text(Vis *vis, Text *text) {
 	File *file = calloc(1, sizeof(*file));
 	if (!file)
 		return NULL;
+	file->fd = -1;
 	file->text = text;
 	file->stat = text_stat(text);
 	if (vis->files)
@@ -364,6 +365,15 @@ bool vis_window_new(Vis *vis, const char *filename) {
 	return true;
 }
 
+bool vis_window_new_fd(Vis *vis, int fd) {
+	if (fd == -1)
+		return false;
+	if (!vis_window_new(vis, NULL))
+		return false;
+	vis->win->file->fd = fd;
+	return true;
+}
+
 bool vis_window_closable(Win *win) {
 	if (!win || !text_modified(win->file->text))
 		return true;
@@ -949,13 +959,11 @@ static void vis_args(Vis *vis, int argc, char *argv[]) {
 
 	if (!vis->windows && vis->running) {
 		if (!strcmp(argv[argc-1], "-")) {
-			if (!vis_window_new(vis, NULL))
+			if (!vis_window_new_fd(vis, STDOUT_FILENO))
 				vis_die(vis, "Can not create empty buffer\n");
 			ssize_t len = 0;
 			char buf[PIPE_BUF];
-			File *file = vis->win->file;
-			Text *txt = file->text;
-			file->is_stdin = true;
+			Text *txt = vis_text(vis);
 			while ((len = read(STDIN_FILENO, buf, sizeof buf)) > 0)
 				text_insert(txt, text_size(txt), buf, len);
 			if (len == -1)
diff --git a/vis.h b/vis.h
index 8c981fb..e3d0812 100644
--- a/vis.h
+++ b/vis.h
@@ -86,6 +86,11 @@ void vis_suspend(Vis*);
  * in another window, share the underlying text that is changes will be
  * visible in both windows */
 bool vis_window_new(Vis*, const char *filename);
+/* Creates a new window and underlying file object associated with the
+ * given output file descriptor. No data is read from `fd`, but write
+ * commands without an explicit filename will instead write to the file
+ * descriptor */
+bool vis_window_new_fd(Vis*, int fd);
 /* reload the file currently displayed in the window from disk */
 bool vis_window_reload(Win*);
 /* check whether closing the window would loose unsaved changes */