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