Send all three of stdin, stdout, stderr from the client to the server, so that

commands can directly make use of them. This means that load-buffer and
save-buffer can have "-" as the file to read from stdin or write to stdout.

This is a protocol version bump so the tmux server will need to be restarted
after upgrade (or an older client used).

client.c

@@ -96,7 +96,6 @@ server_started:
 
 	if (cmdflags & CMD_SENDENVIRON)
 		client_send_environ();
-	if (isatty(STDIN_FILENO))
 	client_send_identify(flags);
 
 	return (&client_ibuf);
@@ -131,6 +130,14 @@ client_send_identify(int flags)
 		fatal("dup failed");
 	imsg_compose(&client_ibuf,
 	    MSG_IDENTIFY, PROTOCOL_VERSION, -1, fd, &data, sizeof data);
+
+	if ((fd = dup(STDOUT_FILENO)) == -1)
+		fatal("dup failed");
+	imsg_compose(&client_ibuf, MSG_STDOUT, PROTOCOL_VERSION, -1, fd, NULL, 0);
+
+	if ((fd = dup(STDERR_FILENO)) == -1)
+		fatal("dup failed");
+	imsg_compose(&client_ibuf, MSG_STDERR, PROTOCOL_VERSION, -1, fd, NULL, 0);
 }
 
 void

cmd-load-buffer.c

@@ -16,10 +16,13 @@
  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
+#include <sys/types.h>
+
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 
 #include "tmux.h"
 
@@ -45,7 +48,7 @@ cmd_load_buffer_exec(struct cmd *self, struct cmd_ctx *ctx)
 {
 	struct cmd_buffer_data	*data = self->data;
 	struct session		*s;
-	FILE			*f;
+	FILE			*f, *close_f;
 	char		      	*pdata, *new_pdata;
 	size_t			 psize;
 	u_int			 limit;
@@ -54,10 +57,24 @@ cmd_load_buffer_exec(struct cmd *self, struct cmd_ctx *ctx)
 	if ((s = cmd_find_session(ctx, data->target)) == NULL)
 		return (-1);
 
+	if (strcmp(data->arg, "-") == 0 ) {
+		if (ctx->cmdclient == NULL) {
+			ctx->error(ctx, "%s: can't read from stdin", data->arg);
+			return (-1);
+		}
+		f = ctx->cmdclient->stdin_file;
+		if (isatty(fileno(ctx->cmdclient->stdin_file))) {
+			ctx->error(ctx, "%s: stdin is a tty", data->arg);
+			return (-1);
+		}
+		close_f = NULL;
+	} else {
 		if ((f = fopen(data->arg, "rb")) == NULL) {
 			ctx->error(ctx, "%s: %s", data->arg, strerror(errno));
 			return (-1);
 		}
+		close_f = f;
+	}
 
 	pdata = NULL;
 	psize = 0;
@@ -77,7 +94,8 @@ cmd_load_buffer_exec(struct cmd *self, struct cmd_ctx *ctx)
 	if (pdata != NULL)
 		pdata[psize] = '\0';
 
-	fclose(f);
+	if (close_f != NULL)
+		fclose(close_f);
 
 	limit = options_get_number(&s->options, "buffer-limit");
 	if (data->buffer == -1) {
@@ -94,6 +112,7 @@ cmd_load_buffer_exec(struct cmd *self, struct cmd_ctx *ctx)
 error:
 	if (pdata != NULL)
 		xfree(pdata);
-	fclose(f);
+	if (close_f != NULL)
+		fclose(close_f);
 	return (-1);
 }

cmd-save-buffer.c

@@ -48,7 +48,7 @@ cmd_save_buffer_exec(struct cmd *self, struct cmd_ctx *ctx)
 	struct session		*s;
 	struct paste_buffer	*pb;
 	mode_t			mask;
-	FILE			*f;
+	FILE			*f, *close_f;
 
 	if ((s = cmd_find_session(ctx, data->target)) == NULL)
 		return (-1);
@@ -65,6 +65,14 @@ cmd_save_buffer_exec(struct cmd *self, struct cmd_ctx *ctx)
 		}
 	}
 
+	if (strcmp(data->arg, "-") == 0) {
+		if (ctx->cmdclient == NULL) {
+			ctx->error(ctx, "%s: can't write to stdout", data->arg);
+			return (-1);
+		}
+		f = ctx->cmdclient->stdout_file;
+		close_f = NULL;
+	} else {
 		mask = umask(S_IRWXG | S_IRWXO);
 		if (cmd_check_flag(data->chflags, 'a'))
 			f = fopen(data->arg, "ab");
@@ -75,6 +83,8 @@ cmd_save_buffer_exec(struct cmd *self, struct cmd_ctx *ctx)
 			ctx->error(ctx, "%s: %s", data->arg, strerror(errno));
 			return (-1);
 		}
+		close_f = f;
+	}
 
 	if (fwrite(pb->data, 1, pb->size, f) != pb->size) {
 	    	ctx->error(ctx, "%s: fwrite error", data->arg);
@@ -82,7 +92,8 @@ cmd_save_buffer_exec(struct cmd *self, struct cmd_ctx *ctx)
 	    	return (-1);
 	}
 
-	fclose(f);
+	if (close_f != NULL)
+		fclose(close_f);
 
 	return (0);
 }

server-client.c

@@ -69,6 +69,10 @@ server_client_create(int fd)
 
 	ARRAY_INIT(&c->prompt_hdata);
 
+	c->stdin_file = NULL;
+	c->stdout_file = NULL;
+	c->stderr_file = NULL;
+
 	c->tty.fd = -1;
 	c->title = NULL;
 
@@ -118,6 +122,13 @@ server_client_lost(struct client *c)
 	if (c->flags & CLIENT_TERMINAL)
 		tty_free(&c->tty);
 
+	if (c->stdin_file != NULL)
+		fclose(c->stdin_file);
+	if (c->stdout_file != NULL)
+		fclose(c->stdout_file);
+	if (c->stderr_file != NULL)
+		fclose(c->stderr_file);
+
 	screen_free(&c->status);
 	job_tree_free(&c->status_jobs);
 
@@ -555,8 +566,31 @@ server_client_msg_dispatch(struct client *c)
 				fatalx("MSG_IDENTIFY missing fd");
 			memcpy(&identifydata, imsg.data, sizeof identifydata);
 
+			c->stdin_file = fdopen(imsg.fd, "r");
+			if (c->stdin_file == NULL)
+				fatal("fdopen(stdin) failed");
 			server_client_msg_identify(c, &identifydata, imsg.fd);
 			break;
+		case MSG_STDOUT:
+			if (datalen != 0)
+				fatalx("bad MSG_STDOUT size");
+			if (imsg.fd == -1)
+				fatalx("MSG_STDOUT missing fd");
+
+			c->stdout_file = fdopen(imsg.fd, "w");
+			if (c->stdout_file == NULL)
+				fatal("fdopen(stdout) failed");
+			break;
+		case MSG_STDERR:
+			if (datalen != 0)
+				fatalx("bad MSG_STDERR size");
+			if (imsg.fd == -1)
+				fatalx("MSG_STDERR missing fd");
+
+			c->stderr_file = fdopen(imsg.fd, "w");
+			if (c->stderr_file == NULL)
+				fatal("fdopen(stderr) failed");
+			break;
 		case MSG_RESIZE:
 			if (datalen != 0)
 				fatalx("bad MSG_RESIZE size");
@@ -622,45 +656,45 @@ server_client_msg_dispatch(struct client *c)
 void printflike2
 server_client_msg_error(struct cmd_ctx *ctx, const char *fmt, ...)
 {
-	struct msg_print_data	data;
 	va_list	ap;
 
 	va_start(ap, fmt);
-	xvsnprintf(data.msg, sizeof data.msg, fmt, ap);
+	vfprintf(ctx->cmdclient->stderr_file, fmt, ap);
 	va_end(ap);
 
-	server_write_client(ctx->cmdclient, MSG_ERROR, &data, sizeof data);
+	fputc('\n', ctx->cmdclient->stderr_file);
+	fflush(ctx->cmdclient->stderr_file);
 }
 
 /* Callback to send print message to client. */
 void printflike2
 server_client_msg_print(struct cmd_ctx *ctx, const char *fmt, ...)
 {
-	struct msg_print_data	data;
 	va_list	ap;
 
 	va_start(ap, fmt);
-	xvsnprintf(data.msg, sizeof data.msg, fmt, ap);
+	vfprintf(ctx->cmdclient->stdout_file, fmt, ap);
 	va_end(ap);
 
-	server_write_client(ctx->cmdclient, MSG_PRINT, &data, sizeof data);
+	fputc('\n', ctx->cmdclient->stdout_file);
+	fflush(ctx->cmdclient->stdout_file);
 }
 
 /* Callback to send print message to client, if not quiet. */
 void printflike2
 server_client_msg_info(struct cmd_ctx *ctx, const char *fmt, ...)
 {
-	struct msg_print_data	data;
 	va_list	ap;
 
 	if (options_get_number(&global_options, "quiet"))
 		return;
 
 	va_start(ap, fmt);
-	xvsnprintf(data.msg, sizeof data.msg, fmt, ap);
+	vfprintf(ctx->cmdclient->stdout_file, fmt, ap);
 	va_end(ap);
 
-	server_write_client(ctx->cmdclient, MSG_PRINT, &data, sizeof data);
+	fputc('\n', ctx->cmdclient->stderr_file);
+	fflush(ctx->cmdclient->stdout_file);
 }
 
 /* Handle command message. */
@@ -717,13 +751,19 @@ void
 server_client_msg_identify(
     struct client *c, struct msg_identify_data *data, int fd)
 {
+	int	tty_fd;
+
 	c->cwd = NULL;
 	data->cwd[(sizeof data->cwd) - 1] = '\0';
 	if (*data->cwd != '\0')
 		c->cwd = xstrdup(data->cwd);
 
+	if (!isatty(fd))
+	    return;
+	if ((tty_fd = dup(fd)) == -1)
+		fatal("dup failed");
 	data->term[(sizeof data->term) - 1] = '\0';
-	tty_init(&c->tty, fd, data->term);
+	tty_init(&c->tty, tty_fd, data->term);
 	if (data->flags & IDENTIFY_UTF8)
 		c->tty.flags |= TTY_UTF8;
 	if (data->flags & IDENTIFY_256COLOURS)

tmux.c

@@ -596,7 +596,6 @@ main_dispatch(const char *shellcmd)
 {
 	struct imsg		imsg;
 	ssize_t			n, datalen;
-	struct msg_print_data	printdata;
 	struct msg_shell_data	shelldata;
 
 	if ((n = imsg_read(main_ibuf)) == -1 || n == 0)
@@ -616,17 +615,6 @@ main_dispatch(const char *shellcmd)
 				fatalx("bad MSG_EXIT size");
 
 			exit(main_exitval);
-		case MSG_ERROR:
-		case MSG_PRINT:
-			if (datalen != sizeof printdata)
-				fatalx("bad MSG_PRINT size");
-			memcpy(&printdata, imsg.data, sizeof printdata);
-			printdata.msg[(sizeof printdata.msg) - 1] = '\0';
-
-			log_info("%s", printdata.msg);
-			if (imsg.hdr.type == MSG_ERROR)
-				main_exitval = 1;
-			break;
 		case MSG_READY:
 			if (datalen != 0)
 				fatalx("bad MSG_READY size");

tmux.h

@@ -19,7 +19,7 @@
 #ifndef TMUX_H
 #define TMUX_H
 
-#define PROTOCOL_VERSION 5
+#define PROTOCOL_VERSION 6
 
 #include <sys/param.h>
 #include <sys/time.h>
@@ -68,7 +68,6 @@ extern char   **environ;
  */
 #define COMMAND_LENGTH 2048	/* packed argv size */
 #define TERMINAL_LENGTH 128	/* length of TERM environment variable */
-#define PRINT_LENGTH 512	/* printed error/message size */
 #define ENVIRON_LENGTH 1024	/* environment variable length */
 
 /*
@@ -373,7 +372,9 @@ enum msgtype {
 	MSG_ENVIRON,
 	MSG_UNLOCK,
 	MSG_LOCK,
-	MSG_SHELL
+	MSG_SHELL,
+	MSG_STDERR,
+	MSG_STDOUT,
 };
 
 /*
@@ -381,10 +382,6 @@ enum msgtype {
  *
  * Don't forget to bump PROTOCOL_VERSION if any of these change!
  */
-struct msg_print_data {
-	char		msg[PRINT_LENGTH];
-};
-
 struct msg_command_data {
 	pid_t		pid;			/* pid from $TMUX or -1 */
 	u_int		idx;			/* index from $TMUX */
@@ -1080,6 +1077,10 @@ struct client {
 	char		*cwd;
 
 	struct tty	 tty;
+	FILE		*stdin_file;
+	FILE		*stdout_file;
+	FILE		*stderr_file;
+
 	struct event	 repeat_timer;
 
 	struct timeval	 status_timer;