1 /* $OpenBSD: cmd-pipe-pane.c,v 1.36 2016/01/19 15:59:12 nicm Exp $ */ 2 3 /* 4 * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com> 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 <stdlib.h> 26 #include <string.h> 27 #include <time.h> 28 #include <unistd.h> 29 30 #include "tmux.h" 31 32 /* 33 * Open pipe to redirect pane output. If already open, close first. 34 */ 35 36 enum cmd_retval cmd_pipe_pane_exec(struct cmd *, struct cmd_q *); 37 38 void cmd_pipe_pane_error_callback(struct bufferevent *, short, void *); 39 40 const struct cmd_entry cmd_pipe_pane_entry = { 41 .name = "pipe-pane", 42 .alias = "pipep", 43 44 .args = { "ot:", 0, 1 }, 45 .usage = "[-o] " CMD_TARGET_PANE_USAGE " [command]", 46 47 .tflag = CMD_PANE, 48 49 .flags = 0, 50 .exec = cmd_pipe_pane_exec 51 }; 52 53 enum cmd_retval 54 cmd_pipe_pane_exec(struct cmd *self, struct cmd_q *cmdq) 55 { 56 struct args *args = self->args; 57 struct client *c = cmdq->state.c; 58 struct window_pane *wp = cmdq->state.tflag.wp; 59 struct session *s = cmdq->state.tflag.s; 60 struct winlink *wl = cmdq->state.tflag.wl; 61 char *cmd; 62 int old_fd, pipe_fd[2], null_fd; 63 struct format_tree *ft; 64 65 /* Destroy the old pipe. */ 66 old_fd = wp->pipe_fd; 67 if (wp->pipe_fd != -1) { 68 bufferevent_free(wp->pipe_event); 69 close(wp->pipe_fd); 70 wp->pipe_fd = -1; 71 } 72 73 /* If no pipe command, that is enough. */ 74 if (args->argc == 0 || *args->argv[0] == '\0') 75 return (CMD_RETURN_NORMAL); 76 77 /* 78 * With -o, only open the new pipe if there was no previous one. This 79 * allows a pipe to be toggled with a single key, for example: 80 * 81 * bind ^p pipep -o 'cat >>~/output' 82 */ 83 if (args_has(self->args, 'o') && old_fd != -1) 84 return (CMD_RETURN_NORMAL); 85 86 /* Open the new pipe. */ 87 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe_fd) != 0) { 88 cmdq_error(cmdq, "socketpair error: %s", strerror(errno)); 89 return (CMD_RETURN_ERROR); 90 } 91 92 /* Expand the command. */ 93 ft = format_create(cmdq, 0); 94 format_defaults(ft, c, s, wl, wp); 95 cmd = format_expand_time(ft, args->argv[0], time(NULL)); 96 format_free(ft); 97 98 /* Fork the child. */ 99 switch (fork()) { 100 case -1: 101 cmdq_error(cmdq, "fork error: %s", strerror(errno)); 102 103 free(cmd); 104 return (CMD_RETURN_ERROR); 105 case 0: 106 /* Child process. */ 107 close(pipe_fd[0]); 108 clear_signals(1); 109 110 if (dup2(pipe_fd[1], STDIN_FILENO) == -1) 111 _exit(1); 112 if (pipe_fd[1] != STDIN_FILENO) 113 close(pipe_fd[1]); 114 115 null_fd = open(_PATH_DEVNULL, O_WRONLY, 0); 116 if (dup2(null_fd, STDOUT_FILENO) == -1) 117 _exit(1); 118 if (dup2(null_fd, STDERR_FILENO) == -1) 119 _exit(1); 120 if (null_fd != STDOUT_FILENO && null_fd != STDERR_FILENO) 121 close(null_fd); 122 123 closefrom(STDERR_FILENO + 1); 124 125 execl(_PATH_BSHELL, "sh", "-c", cmd, (char *) NULL); 126 _exit(1); 127 default: 128 /* Parent process. */ 129 close(pipe_fd[1]); 130 131 wp->pipe_fd = pipe_fd[0]; 132 wp->pipe_off = EVBUFFER_LENGTH(wp->event->input); 133 134 wp->pipe_event = bufferevent_new(wp->pipe_fd, 135 NULL, NULL, cmd_pipe_pane_error_callback, wp); 136 bufferevent_enable(wp->pipe_event, EV_WRITE); 137 138 setblocking(wp->pipe_fd, 0); 139 140 free(cmd); 141 return (CMD_RETURN_NORMAL); 142 } 143 } 144 145 void 146 cmd_pipe_pane_error_callback(__unused struct bufferevent *bufev, 147 __unused short what, void *data) 148 { 149 struct window_pane *wp = data; 150 151 bufferevent_free(wp->pipe_event); 152 close(wp->pipe_fd); 153 wp->pipe_fd = -1; 154 } 155