logging.c

LINUX下读写NTFS分区的工具。 已经集成了通过LIBCONV库支持中文的代码。

		return 0;

	va_start(args, format);
	errno = olderr;
	ret = ntfs_log.handler(function, file, line, level, data, format, args);
	va_end(args);

	errno = olderr;
	return ret;
}


/**
 * ntfs_log_handler_syslog - syslog logging handler
 * @function:	Function in which the log line occurred
 * @file:	File in which the log line occurred
 * @line:	Line number on which the log line occurred
 * @level:	Level at which the line is logged
 * @data:	User specified data, possibly specific to a handler
 * @format:	printf-style formatting string
 * @args:	Arguments to be formatted
 *
 * A simple syslog logging handler.  Ignores colors.
 *
 * Returns:  -1  Error occurred
 *            0  Message wasn't logged
 *          num  Number of output characters
 */


#ifdef HAVE_SYSLOG_H

#define LOG_LINE_LEN 	512

int ntfs_log_handler_syslog(const char *function  __attribute__((unused)),
			    const char *file __attribute__((unused)), 
			    int line __attribute__((unused)), u32 level, 
			    void *data __attribute__((unused)), 
			    const char *format, va_list args)
{
	char logbuf[LOG_LINE_LEN];
	int ret, olderr = errno;

#ifndef DEBUG
	if ((level & NTFS_LOG_LEVEL_PERROR) && errno == ENOSPC)
		return 1;
#endif	
	ret = vsnprintf(logbuf, LOG_LINE_LEN, format, args);
	if (ret < 0) {
		vsyslog(LOG_NOTICE, format, args);
		ret = 1;
		goto out;
	}
	
	if ((LOG_LINE_LEN > ret + 3) && (level & NTFS_LOG_LEVEL_PERROR)) {
		strncat(logbuf, ": ", LOG_LINE_LEN - ret - 1);
		strncat(logbuf, strerror(olderr), LOG_LINE_LEN - (ret + 3));
		ret = strlen(logbuf);
	}
	
	syslog(LOG_NOTICE, "%s", logbuf);
out:
	errno = olderr;
	return ret;
}
#endif

/**
 * ntfs_log_handler_fprintf - Basic logging handler
 * @function:	Function in which the log line occurred
 * @file:	File in which the log line occurred
 * @line:	Line number on which the log line occurred
 * @level:	Level at which the line is logged
 * @data:	User specified data, possibly specific to a handler
 * @format:	printf-style formatting string
 * @args:	Arguments to be formatted
 *
 * A simple logging handler.  This is where the log line is finally displayed.
 * It is more likely that you will want to set the handler to either
 * ntfs_log_handler_outerr or ntfs_log_handler_stderr.
 *
 * Note: For this handler, @data is a pointer to a FILE output stream.
 *       If @data is NULL, nothing will be displayed.
 *
 * Returns:  -1  Error occurred
 *            0  Message wasn't logged
 *          num  Number of output characters
 */
int ntfs_log_handler_fprintf(const char *function, const char *file,
	int line, u32 level, void *data, const char *format, va_list args)
{
#ifdef DEBUG
	int i;
#endif
	int ret = 0;
	int olderr = errno;
	FILE *stream;
	const char *col_prefix = NULL;
	const char *col_suffix = NULL;

	if (!data)		/* Interpret data as a FILE stream. */
		return 0;	/* If it's NULL, we can't do anything. */
	stream = (FILE*)data;

#ifdef DEBUG
	if (level == NTFS_LOG_LEVEL_LEAVE) {
		if (tab)
			tab--;
		return 0;
	}
#endif	
	if (ntfs_log.flags & NTFS_LOG_FLAG_COLOUR) {
		/* Pick a colour determined by the log level */
		switch (level) {
			case NTFS_LOG_LEVEL_DEBUG:
				col_prefix = col_green;
				col_suffix = col_end;
				break;
			case NTFS_LOG_LEVEL_TRACE:
				col_prefix = col_cyan;
				col_suffix = col_end;
				break;
			case NTFS_LOG_LEVEL_WARNING:
				col_prefix = col_yellow;
				col_suffix = col_end;
				break;
			case NTFS_LOG_LEVEL_ERROR:
			case NTFS_LOG_LEVEL_PERROR:
				col_prefix = col_red;
				col_suffix = col_end;
				break;
			case NTFS_LOG_LEVEL_CRITICAL:
				col_prefix = col_redinv;
				col_suffix = col_end;
				break;
		}
	}
	
#ifdef DEBUG
	for (i = 0; i < tab; i++)
		ret += fprintf(stream, " ");
#endif	
	if (col_prefix)
		ret += fprintf(stream, col_prefix);

	if ((ntfs_log.flags & NTFS_LOG_FLAG_ONLYNAME) &&
	    (strchr(file, PATH_SEP)))		/* Abbreviate the filename */
		file = strrchr(file, PATH_SEP) + 1;

	if (ntfs_log.flags & NTFS_LOG_FLAG_PREFIX)	/* Prefix the output */
		ret += fprintf(stream, "%s", ntfs_log_get_prefix(level));

	if (ntfs_log.flags & NTFS_LOG_FLAG_FILENAME)	/* Source filename */
		ret += fprintf(stream, "%s ", file);

	if (ntfs_log.flags & NTFS_LOG_FLAG_LINE)	/* Source line number */
		ret += fprintf(stream, "(%d) ", line);

	if ((ntfs_log.flags & NTFS_LOG_FLAG_FUNCTION) || /* Source function */
	    (level & NTFS_LOG_LEVEL_TRACE) || (level & NTFS_LOG_LEVEL_ENTER))
		ret += fprintf(stream, "%s(): ", function);

	ret += vfprintf(stream, format, args);

	if (level & NTFS_LOG_LEVEL_PERROR)
		ret += fprintf(stream, ": %s\n", strerror(olderr));

	if (col_suffix)
		ret += fprintf(stream, col_suffix);

#ifdef DEBUG
	if (level == NTFS_LOG_LEVEL_ENTER)
		tab++;
#endif	
	fflush(stream);
	errno = olderr;
	return ret;
}

/**
 * ntfs_log_handler_null - Null logging handler (no output)
 * @function:	Function in which the log line occurred
 * @file:	File in which the log line occurred
 * @line:	Line number on which the log line occurred
 * @level:	Level at which the line is logged
 * @data:	User specified data, possibly specific to a handler
 * @format:	printf-style formatting string
 * @args:	Arguments to be formatted
 *
 * This handler produces no output.  It provides a way to temporarily disable
 * logging, without having to change the levels and flags.
 *
 * Returns:  0  Message wasn't logged
 */
int ntfs_log_handler_null(const char *function __attribute__((unused)), const char *file __attribute__((unused)),
	int line __attribute__((unused)), u32 level __attribute__((unused)), void *data __attribute__((unused)),
	const char *format __attribute__((unused)), va_list args __attribute__((unused)))
{
	return 0;
}

/**
 * ntfs_log_handler_stdout - All logs go to stdout
 * @function:	Function in which the log line occurred
 * @file:	File in which the log line occurred
 * @line:	Line number on which the log line occurred
 * @level:	Level at which the line is logged
 * @data:	User specified data, possibly specific to a handler
 * @format:	printf-style formatting string
 * @args:	Arguments to be formatted
 *
 * Display a log message to stdout.
 *
 * Note: For this handler, @data is a pointer to a FILE output stream.
 *       If @data is NULL, then stdout will be used.
 *
 * Note: This function calls ntfs_log_handler_fprintf to do the main work.
 *
 * Returns:  -1  Error occurred
 *            0  Message wasn't logged
 *          num  Number of output characters
 */
int ntfs_log_handler_stdout(const char *function, const char *file,
	int line, u32 level, void *data, const char *format, va_list args)
{
	if (!data)
		data = stdout;

	return ntfs_log_handler_fprintf(function, file, line, level, data, format, args);
}

/**
 * ntfs_log_handler_outerr - Logs go to stdout/stderr depending on level
 * @function:	Function in which the log line occurred
 * @file:	File in which the log line occurred
 * @line:	Line number on which the log line occurred
 * @level:	Level at which the line is logged
 * @data:	User specified data, possibly specific to a handler
 * @format:	printf-style formatting string
 * @args:	Arguments to be formatted
 *
 * Display a log message.  The output stream will be determined by the log
 * level.
 *
 * Note: For this handler, @data is a pointer to a FILE output stream.
 *       If @data is NULL, the function ntfs_log_get_stream will be called
 *
 * Note: This function calls ntfs_log_handler_fprintf to do the main work.
 *
 * Returns:  -1  Error occurred
 *            0  Message wasn't logged
 *          num  Number of output characters
 */
int ntfs_log_handler_outerr(const char *function, const char *file,
	int line, u32 level, void *data, const char *format, va_list args)
{
	if (!data)
		data = ntfs_log_get_stream(level);

	return ntfs_log_handler_fprintf(function, file, line, level, data, format, args);
}

/**
 * ntfs_log_handler_stderr - All logs go to stderr
 * @function:	Function in which the log line occurred
 * @file:	File in which the log line occurred
 * @line:	Line number on which the log line occurred
 * @level:	Level at which the line is logged
 * @data:	User specified data, possibly specific to a handler
 * @format:	printf-style formatting string
 * @args:	Arguments to be formatted
 *
 * Display a log message to stderr.
 *
 * Note: For this handler, @data is a pointer to a FILE output stream.
 *       If @data is NULL, then stdout will be used.
 *
 * Note: This function calls ntfs_log_handler_fprintf to do the main work.
 *
 * Returns:  -1  Error occurred
 *            0  Message wasn't logged
 *          num  Number of output characters
 */
int ntfs_log_handler_stderr(const char *function, const char *file,
	int line, u32 level, void *data, const char *format, va_list args)
{
	if (!data)
		data = stderr;

	return ntfs_log_handler_fprintf(function, file, line, level, data, format, args);
}


/**
 * ntfs_log_parse_option - Act upon command line options
 * @option:	Option flag
 *
 * Delegate some of the work of parsing the command line.  All the options begin
 * with "--log-".  Options cause log levels to be enabled in @ntfs_log (the
 * global logging structure).
 *
 * Note: The "colour" option changes the logging handler.
 *
 * Returns:  TRUE  Option understood
 *          FALSE  Invalid log option
 */
BOOL ntfs_log_parse_option(const char *option)
{
	if (strcmp(option, "--log-debug") == 0) {
		ntfs_log_set_levels(NTFS_LOG_LEVEL_DEBUG);
		return TRUE;
	} else if (strcmp(option, "--log-verbose") == 0) {
		ntfs_log_set_levels(NTFS_LOG_LEVEL_VERBOSE);
		return TRUE;
	} else if (strcmp(option, "--log-quiet") == 0) {
		ntfs_log_clear_levels(NTFS_LOG_LEVEL_QUIET);
		return TRUE;
	} else if (strcmp(option, "--log-trace") == 0) {
		ntfs_log_set_levels(NTFS_LOG_LEVEL_TRACE);
		return TRUE;
	} else if ((strcmp(option, "--log-colour") == 0) ||
		   (strcmp(option, "--log-color") == 0)) {
		ntfs_log_set_flags(NTFS_LOG_FLAG_COLOUR);
		return TRUE;
	}

	ntfs_log_debug("Unknown logging option '%s'\n", option);
	return FALSE;
}