Update lttng-ust-abi.h local copy

[lttng-tools.git] / lttng-sessiond / utils.c

/*
 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
 *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; only version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#define _GNU_SOURCE
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <lttngerr.h>

#include "utils.h"

/*
 * Write to writable pipe used to notify a thread.
 */
int notify_thread_pipe(int wpipe)
{
	int ret;

	ret = write(wpipe, "!", 1);
	if (ret < 0) {
		PERROR("write poll pipe");
	}

	return ret;
}

/*
 * Return pointer to home directory path using the env variable HOME.
 *
 * No home, NULL is returned.
 */
const char *get_home_dir(void)
{
	return ((const char *) getenv("HOME"));
}