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 <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 window_pane      *wp;
  54         int                      old_fd, pipe_fd[2], null_fd, mode;
  55
  56         if (cmd_find_pane(ctx, data->target, NULL, &wp) == NULL)
  57                 return (-1);
  58
  59         /* Destroy the old pipe. */
  60         old_fd = wp->pipe_fd;
  61         if (wp->pipe_fd != -1) {
  62                 bufferevent_free(wp->pipe_event);
  63                 close(wp->pipe_fd);
  64                 wp->pipe_fd = -1;
  65         }
  66
  67         /* If no pipe command, that is enough. */
  68         if (data->arg == NULL || *data->arg == '\0')
  69                 return (0);
  70
  71         /*
  72          * With -o, only open the new pipe if there was no previous one. This
  73          * allows a pipe to be toggled with a single key, for example:
  74          *
  75          *      bind ^p pipep -o 'cat >>~/output'
  76          */
  77         if (cmd_check_flag(data->chflags, 'o') && old_fd != -1)
  78                 return (0);
  79
  80         /* Open the new pipe. */
  81         if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe_fd) != 0) {
  82                 ctx->error(ctx, "socketpair error: %s", strerror(errno));
  83                 return (-1);
  84         }
  85
  86         /* Fork the child. */
  87         switch (fork()) {
  88         case -1:
  89                 ctx->error(ctx, "fork error: %s", strerror(errno));
  90                 return (-1);
  91         case 0:
  92                 /* Child process. */
  93                 close(pipe_fd[0]);
  94                 clear_signals();
  95
  96                 if (dup2(pipe_fd[1], STDIN_FILENO) == -1)
  97                         _exit(1);
  98                 if (pipe_fd[1] != STDIN_FILENO)
  99                         close(pipe_fd[1]);
 100
 101                 null_fd = open(_PATH_DEVNULL, O_WRONLY, 0);
 102                 if (dup2(null_fd, STDOUT_FILENO) == -1)
 103                         _exit(1);
 104                 if (dup2(null_fd, STDERR_FILENO) == -1)
 105                         _exit(1);
 106                 if (null_fd != STDOUT_FILENO && null_fd != STDERR_FILENO)
 107                         close(null_fd);
 108
 109                 execl(_PATH_BSHELL, "sh", "-c", data->arg, (char *) NULL);
 110                 _exit(1);
 111         default:
 112                 /* Parent process. */
 113                 close(pipe_fd[1]);
 114
 115                 wp->pipe_fd = pipe_fd[0];
 116                 wp->pipe_off = EVBUFFER_LENGTH(wp->event->input);
 117
 118                 wp->pipe_event = bufferevent_new(wp->pipe_fd,
 119                     NULL, NULL, cmd_pipe_pane_error_callback, wp);
 120                 bufferevent_enable(wp->pipe_event, EV_WRITE);
 121
 122                 if ((mode = fcntl(wp->pipe_fd, F_GETFL)) == -1)
 123                         fatal("fcntl failed");
 124                 if (fcntl(wp->pipe_fd, F_SETFL, mode|O_NONBLOCK) == -1)
 125                         fatal("fcntl failed");
 126                 if (fcntl(wp->pipe_fd, F_SETFD, FD_CLOEXEC) == -1)
 127                         fatal("fcntl failed");
 128                 return (0);
 129         }
 130 }
 131
 132 /* ARGSUSED */
 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 }