src/bin/lttng-sessiond/utils.c

   1 /*
   2  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   3  *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by the Free
   7  * Software Foundation; only version 2 of the License.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  16  * Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <errno.h>
  21 #include <limits.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <unistd.h>
  26
  27 #include <common/lttngerr.h>
  28
  29 #include "utils.h"
  30
  31 /*
  32  * Write to writable pipe used to notify a thread.
  33  */
  34 int notify_thread_pipe(int wpipe)
  35 {
  36         int ret;
  37
  38         ret = write(wpipe, "!", 1);
  39         if (ret < 0) {
  40                 PERROR("write poll pipe");
  41         }
  42
  43         return ret;
  44 }
  45
  46 /*
  47  * Return pointer to home directory path using the env variable HOME.
  48  *
  49  * No home, NULL is returned.
  50  */
  51 const char *get_home_dir(void)
  52 {
  53         return ((const char *) getenv("HOME"));
  54 }