cmd-pipe-pane.c

   1 /* $OpenBSD$ */
   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 <paths.h>
  25 #include <string.h>
  26 #include <time.h>
  27 #include <unistd.h>
  28
  29 #include "tmux.h"
  30
  31 /*
  32  * Open pipe to redirect pane output. If already open, close first.
  33  */
  34
  35 enum cmd_retval  cmd_pipe_pane_exec(struct cmd *, struct cmd_q *);
  36
  37 void    cmd_pipe_pane_error_callback(struct bufferevent *, short, void *);
  38
  39 const struct cmd_entry cmd_pipe_pane_entry = {
  40         "pipe-pane", "pipep",
  41         "ot:", 0, 1,
  42         "[-o] " CMD_TARGET_PANE_USAGE " [command]",
  43         0,
  44         NULL,
  45         NULL,
  46         cmd_pipe_pane_exec
  47 };
  48
  49 enum cmd_retval
  50 cmd_pipe_pane_exec(struct cmd *self, struct cmd_q *cmdq)
  51 {
  52         struct args             *args = self->args;
  53         struct client           *c;
  54         struct window_pane      *wp;
  55         char                    *command;
  56         int                      old_fd, pipe_fd[2], null_fd;
  57
  58         if (cmd_find_pane(cmdq, args_get(args, 't'), NULL, &wp) == NULL)
  59                 return (CMD_RETURN_ERROR);
  60         c = cmd_find_client(cmdq, NULL, 1);
  61
  62         /* Destroy the old pipe. */
  63         old_fd = wp->pipe_fd;
  64         if (wp->pipe_fd != -1) {
  65                 bufferevent_free(wp->pipe_event);
  66                 close(wp->pipe_fd);
  67                 wp->pipe_fd = -1;
  68         }
  69
  70         /* If no pipe command, that is enough. */
  71         if (args->argc == 0 || *args->argv[0] == '\0')
  72                 return (CMD_RETURN_NORMAL);
  73
  74         /*
  75          * With -o, only open the new pipe if there was no previous one. This
  76          * allows a pipe to be toggled with a single key, for example:
  77          *
  78          *      bind ^p pipep -o 'cat >>~/output'
  79          */
  80         if (args_has(self->args, 'o') && old_fd != -1)
  81                 return (CMD_RETURN_NORMAL);
  82
  83         /* Open the new pipe. */
  84         if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe_fd) != 0) {
  85                 cmdq_error(cmdq, "socketpair error: %s", strerror(errno));
  86                 return (CMD_RETURN_ERROR);
  87         }
  88
  89         /* Fork the child. */
  90         switch (fork()) {
  91         case -1:
  92                 cmdq_error(cmdq, "fork error: %s", strerror(errno));
  93                 return (CMD_RETURN_ERROR);
  94         case 0:
  95                 /* Child process. */
  96                 close(pipe_fd[0]);
  97                 clear_signals(1);
  98
  99                 if (dup2(pipe_fd[1], STDIN_FILENO) == -1)
 100                         _exit(1);
 101                 if (pipe_fd[1] != STDIN_FILENO)
 102                         close(pipe_fd[1]);
 103
 104                 null_fd = open(_PATH_DEVNULL, O_WRONLY, 0);
 105                 if (dup2(null_fd, STDOUT_FILENO) == -1)
 106                         _exit(1);
 107                 if (dup2(null_fd, STDERR_FILENO) == -1)
 108                         _exit(1);
 109                 if (null_fd != STDOUT_FILENO && null_fd != STDERR_FILENO)
 110                         close(null_fd);
 111
 112                 closefrom(STDERR_FILENO + 1);
 113
 114                 command = status_replace(
 115                     c, NULL, NULL, NULL, args->argv[0], time(NULL), 0);
 116                 execl(_PATH_BSHELL, "sh", "-c", command, (char *) NULL);
 117                 _exit(1);
 118         default:
 119                 /* Parent process. */
 120                 close(pipe_fd[1]);
 121
 122                 wp->pipe_fd = pipe_fd[0];
 123                 wp->pipe_off = EVBUFFER_LENGTH(wp->event->input);
 124
 125                 wp->pipe_event = bufferevent_new(wp->pipe_fd,
 126                     NULL, NULL, cmd_pipe_pane_error_callback, wp);
 127                 bufferevent_enable(wp->pipe_event, EV_WRITE);
 128
 129                 setblocking(wp->pipe_fd, 0);
 130                 return (CMD_RETURN_NORMAL);
 131         }
 132 }
 133
 134 void
 135 cmd_pipe_pane_error_callback(
 136     unused struct bufferevent *bufev, unused short what, void *data)
 137 {
 138         struct window_pane      *wp = data;
 139
 140         bufferevent_free(wp->pipe_event);
 141         close(wp->pipe_fd);
 142         wp->pipe_fd = -1;
 143 }