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 int     cmd_pipe_pane_exec(struct cmd *, struct cmd_ctx *);
  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         CMD_TARGET_PANE_USAGE "[-o] [command]",
  43         0,
  44         NULL,
  45         NULL,
  46         cmd_pipe_pane_exec
  47 };
  48
  49 int
  50 cmd_pipe_pane_exec(struct cmd *self, struct cmd_ctx *ctx)
  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 ((c = cmd_find_client(ctx, NULL)) == NULL)
  59                 return (-1);
  60
  61         if (cmd_find_pane(ctx, args_get(args, 't'), 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 (args->argc == 0 || *args->argv[0] == '\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 (args_has(self->args, '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, args->argv[0], 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                 setblocking(wp->pipe_fd, 0);
 131                 return (0);
 132         }
 133 }
 134
 135 /* ARGSUSED */
 136 void
 137 cmd_pipe_pane_error_callback(
 138     unused struct bufferevent *bufev, unused short what, void *data)
 139 {
 140         struct window_pane      *wp = data;
 141
 142         bufferevent_free(wp->pipe_event);
 143         close(wp->pipe_fd);
 144         wp->pipe_fd = -1;
 145 }