Zabbix

/*

** Copyright (C) 2001-2025 Zabbix SIA

**

** This program is free software: you can redistribute it and/or modify it under the terms of

** the GNU Affero General Public License as published by the Free Software Foundation, version 3.

**

** 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 Affero General Public License for more details.

**

** You should have received a copy of the GNU Affero General Public License along with this program.

** If not, see <https://www.gnu.org/licenses/>.

**/

​

#include "zbxlog.h"

​

#include "zbxmutexs.h"

#include "zbxcfg.h"

#include "zbxstr.h"

#include "zbxtime.h"

#include "zbxcommon.h"

#ifdef _WINDOWS

#   include "messages.h"

#   include "zbxwinservice.h"

#   include <strsafe.h> /* StringCchPrintf */

static HANDLE       system_log_handle = INVALID_HANDLE_VALUE;

#endif

​

static char     log_filename[MAX_STRING_LEN];

static int      log_type = ZBX_LOG_TYPE_UNDEFINED;

static zbx_mutex_t  log_access = ZBX_MUTEX_NULL;

​

static int      config_log_file_size = -1;  /* max log file size in MB */

​

static int  get_config_log_file_size(void)

{

    if (-1 != config_log_file_size)

        return config_log_file_size;

​

    THIS_SHOULD_NEVER_HAPPEN;

    exit(EXIT_FAILURE);

}

​

#ifdef _WINDOWS

#   define LOCK_LOG     zbx_mutex_lock(log_access)

#   define UNLOCK_LOG   zbx_mutex_unlock(log_access)

#else

#   define LOCK_LOG     lock_log()

#   define UNLOCK_LOG   unlock_log()

#endif

​

#ifdef _WINDOWS

#   define STDIN_FILENO _fileno(stdin)

#   define STDOUT_FILENO    _fileno(stdout)

#   define STDERR_FILENO    _fileno(stderr)

​

#   define ZBX_DEV_NULL "NUL"

​

#   define dup2(fd1, fd2)   _dup2(fd1, fd2)

#else

#   define ZBX_DEV_NULL "/dev/null"

#endif

​

int zbx_redirect_stdio(const char *filename)

{

    const char  default_file[] = ZBX_DEV_NULL;

    int     open_flags = O_WRONLY, fd;

​

    if (NULL != filename && '\0' != *filename)

        open_flags |= O_CREAT | O_APPEND;

    else

        filename = default_file;

​

    if (-1 == (fd = open(filename, open_flags, 0666)))

    {

        zbx_error("cannot open \"%s\": %s", filename, zbx_strerror(errno));

        return FAIL;

    }

​

    fflush(stdout);

    if (-1 == dup2(fd, STDOUT_FILENO))

        zbx_error("cannot redirect stdout to \"%s\": %s", filename, zbx_strerror(errno));

​

    fflush(stderr);

    if (-1 == dup2(fd, STDERR_FILENO))

        zbx_error("cannot redirect stderr to \"%s\": %s", filename, zbx_strerror(errno));

​

    close(fd);

​

    if (-1 == (fd = open(default_file, O_RDONLY)))

    {