xref: /netbsd-src/external/bsd/tmux/dist/cmd-pipe-pane.c (revision 46f5119e40af2e51998f686b2fdcc76b5488f7f3)
1 /* $Id: cmd-pipe-pane.c,v 1.1.1.1 2011/03/10 09:15:37 jmmv Exp $ */
2 
3 /*
4  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 #include <sys/socket.h>
21 
22 #include <errno.h>
23 #include <fcntl.h>
24 #include <string.h>
25 #include <time.h>
26 #include <unistd.h>
27 
28 #include "tmux.h"
29 
30 /*
31  * Open pipe to redirect pane output. If already open, close first.
32  */
33 
34 int	cmd_pipe_pane_exec(struct cmd *, struct cmd_ctx *);
35 
36 void	cmd_pipe_pane_error_callback(struct bufferevent *, short, void *);
37 
38 const struct cmd_entry cmd_pipe_pane_entry = {
39 	"pipe-pane", "pipep",
40 	CMD_TARGET_PANE_USAGE "[-o] [command]",
41 	CMD_ARG01, "o",
42 	cmd_target_init,
43 	cmd_target_parse,
44 	cmd_pipe_pane_exec,
45 	cmd_target_free,
46 	cmd_target_print
47 };
48 
49 int
50 cmd_pipe_pane_exec(struct cmd *self, struct cmd_ctx *ctx)
51 {
52 	struct cmd_target_data	*data = self->data;
53 	struct client		*c;
54 	struct window_pane	*wp;
55 	char			*command;
56 	int			 old_fd, pipe_fd[2], null_fd, mode;
57 
58 	if ((c = cmd_find_client(ctx, NULL)) == NULL)
59 		return (-1);
60 
61 	if (cmd_find_pane(ctx, data->target, NULL, &wp) == NULL)
62 		return (-1);
63 
64 	/* Destroy the old pipe. */
65 	old_fd = wp->pipe_fd;
66 	if (wp->pipe_fd != -1) {
67 		bufferevent_free(wp->pipe_event);
68 		close(wp->pipe_fd);
69 		wp->pipe_fd = -1;
70 	}
71 
72 	/* If no pipe command, that is enough. */
73 	if (data->arg == NULL || *data->arg == '\0')
74 		return (0);
75 
76 	/*
77 	 * With -o, only open the new pipe if there was no previous one. This
78 	 * allows a pipe to be toggled with a single key, for example:
79 	 *
80 	 *	bind ^p pipep -o 'cat >>~/output'
81 	 */
82 	if (cmd_check_flag(data->chflags, 'o') && old_fd != -1)
83 		return (0);
84 
85 	/* Open the new pipe. */
86 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe_fd) != 0) {
87 		ctx->error(ctx, "socketpair error: %s", strerror(errno));
88 		return (-1);
89 	}
90 
91 	/* Fork the child. */
92 	switch (fork()) {
93 	case -1:
94 		ctx->error(ctx, "fork error: %s", strerror(errno));
95 		return (-1);
96 	case 0:
97 		/* Child process. */
98 		close(pipe_fd[0]);
99 		clear_signals(1);
100 
101 		if (dup2(pipe_fd[1], STDIN_FILENO) == -1)
102 			_exit(1);
103 		if (pipe_fd[1] != STDIN_FILENO)
104 			close(pipe_fd[1]);
105 
106 		null_fd = open(_PATH_DEVNULL, O_WRONLY, 0);
107 		if (dup2(null_fd, STDOUT_FILENO) == -1)
108 			_exit(1);
109 		if (dup2(null_fd, STDERR_FILENO) == -1)
110 			_exit(1);
111 		if (null_fd != STDOUT_FILENO && null_fd != STDERR_FILENO)
112 			close(null_fd);
113 
114 		closefrom(STDERR_FILENO + 1);
115 
116 		command = status_replace(c, NULL, data->arg, time(NULL), 0);
117 		execl(_PATH_BSHELL, "sh", "-c", command, (char *) NULL);
118 		_exit(1);
119 	default:
120 		/* Parent process. */
121 		close(pipe_fd[1]);
122 
123 		wp->pipe_fd = pipe_fd[0];
124 		wp->pipe_off = EVBUFFER_LENGTH(wp->event->input);
125 
126 		wp->pipe_event = bufferevent_new(wp->pipe_fd,
127 		    NULL, NULL, cmd_pipe_pane_error_callback, wp);
128 		bufferevent_enable(wp->pipe_event, EV_WRITE);
129 
130 		if ((mode = fcntl(wp->pipe_fd, F_GETFL)) == -1)
131 			fatal("fcntl failed");
132 		if (fcntl(wp->pipe_fd, F_SETFL, mode|O_NONBLOCK) == -1)
133 			fatal("fcntl failed");
134 		return (0);
135 	}
136 }
137 
138 /* ARGSUSED */
139 void
140 cmd_pipe_pane_error_callback(
141     unused struct bufferevent *bufev, unused short what, void *data)
142 {
143 	struct window_pane	*wp = data;
144 
145 	bufferevent_free(wp->pipe_event);
146 	close(wp->pipe_fd);
147 	wp->pipe_fd = -1;
148 }
149