cmd-pipe-pane.c

   1 /* $Id: cmd-pipe-pane.c,v 1.10 2009-12-04 22:14:47 tcunha 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 <unistd.h>
  26
  27 #include "tmux.h"
  28
  29 /*
  30  * Open pipe to redirect pane output. If already open, close first.
  31  */
  32
  33 int     cmd_pipe_pane_exec(struct cmd *, struct cmd_ctx *);
  34
  35 void    cmd_pipe_pane_error_callback(struct bufferevent *, short, void *);
  36
  37 const struct cmd_entry cmd_pipe_pane_entry = {
  38         "pipe-pane", "pipep",
  39         CMD_TARGET_PANE_USAGE "[-o] [command]",
  40         CMD_ARG01, "o",
  41         cmd_target_init,
  42         cmd_target_parse,
  43         cmd_pipe_pane_exec,
  44         cmd_target_free,
  45         cmd_target_print
  46 };
  47
  48 int
  49 cmd_pipe_pane_exec(struct cmd *self, struct cmd_ctx *ctx)
  50 {
  51         struct cmd_target_data  *data = self->data;
  52         struct window_pane      *wp;
  53         int                      old_fd, pipe_fd[2], null_fd, mode;
  54
  55         if (cmd_find_pane(ctx, data->target, NULL, &wp) == NULL)
  56                 return (-1);
  57
  58         /* Destroy the old pipe. */
  59         old_fd = wp->pipe_fd;
  60         if (wp->pipe_fd != -1) {
  61                 bufferevent_free(wp->pipe_event);
  62                 close(wp->pipe_fd);
  63                 wp->pipe_fd = -1;
  64         }
  65
  66         /* If no pipe command, that is enough. */
  67         if (data->arg == NULL || *data->arg == '\0')
  68                 return (0);
  69
  70         /*
  71          * With -o, only open the new pipe if there was no previous one. This
  72          * allows a pipe to be toggled with a single key, for example:
  73          *
  74          *      bind ^p pipep -o 'cat >>~/output'
  75          */
  76         if (cmd_check_flag(data->chflags, 'o') && old_fd != -1)
  77                 return (0);
  78
  79         /* Open the new pipe. */
  80         if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe_fd) != 0) {
  81                 ctx->error(ctx, "socketpair error: %s", strerror(errno));
  82                 return (-1);
  83         }
  84
  85         /* Fork the child. */
  86         switch (fork()) {
  87         case -1:
  88                 ctx->error(ctx, "fork error: %s", strerror(errno));
  89                 return (-1);
  90         case 0:
  91                 /* Child process. */
  92                 close(pipe_fd[0]);
  93                 server_signal_clear();
  94
  95                 if (dup2(pipe_fd[1], STDIN_FILENO) == -1)
  96                         _exit(1);
  97                 if (pipe_fd[1] != STDIN_FILENO)
  98                         close(pipe_fd[1]);
  99
 100                 null_fd = open(_PATH_DEVNULL, O_WRONLY, 0);
 101                 if (dup2(null_fd, STDOUT_FILENO) == -1)
 102                         _exit(1);
 103                 if (dup2(null_fd, STDERR_FILENO) == -1)
 104                         _exit(1);
 105                 if (null_fd != STDOUT_FILENO && null_fd != STDERR_FILENO)
 106                         close(null_fd);
 107
 108                 execl(_PATH_BSHELL, "sh", "-c", data->arg, (char *) NULL);
 109                 _exit(1);
 110         default:
 111                 /* Parent process. */
 112                 close(pipe_fd[1]);
 113
 114                 wp->pipe_fd = pipe_fd[0];
 115                 wp->pipe_off = EVBUFFER_LENGTH(wp->event->input);
 116
 117                 wp->pipe_event = bufferevent_new(wp->pipe_fd,
 118                     NULL, NULL, cmd_pipe_pane_error_callback, wp);
 119                 bufferevent_enable(wp->pipe_event, EV_WRITE);
 120
 121                 if ((mode = fcntl(wp->pipe_fd, F_GETFL)) == -1)
 122                         fatal("fcntl failed");
 123                 if (fcntl(wp->pipe_fd, F_SETFL, mode|O_NONBLOCK) == -1)
 124                         fatal("fcntl failed");
 125                 if (fcntl(wp->pipe_fd, F_SETFD, FD_CLOEXEC) == -1)
 126                         fatal("fcntl failed");
 127                 return (0);
 128         }
 129 }
 130
 131 /* ARGSUSED */
 132 void
 133 cmd_pipe_pane_error_callback(
 134     unused struct bufferevent *bufev, unused short what, void *data)
 135 {
 136         struct window_pane      *wp = data;
 137
 138         bufferevent_free(wp->pipe_event);
 139         close(wp->pipe_fd);
 140         wp->pipe_fd = -1;
 141 }