Method FormatTime

Source/script2.cpp:6221–6525

///////////////////////////////

ResultType Line::FormatTime(char *aYYYYMMDD, char *aFormat)
// The compressed code size of this function is about 1 KB (2 KB uncompressed), which compares
// favorably to using setlocale()+strftime(), which together are about 8 KB of compressed code
// (setlocale() seems to be needed to put the user's or system's locale into effect for strftime()).
// setlocale() weighs in at about 6.5 KB compressed (14 KB uncompressed).
{
	Var *output_var = ResolveVarOfArg(0);
	if (!output_var)
		return FAIL;

	#define FT_MAX_INPUT_CHARS 2000  // In preparation for future use of TCHARs, since GetDateFormat() uses char-count not size.
	// Input/format length is restricted since it must be translated and expanded into a new format
	// string that uses single quotes around non-alphanumeric characters such as punctuation:
	if (strlen(aFormat) > FT_MAX_INPUT_CHARS)
		return output_var->Assign();

	// Worst case expansion: .d.d.d.d. (9 chars) --> '.'d'.'d'.'d'.'d'.' (19 chars)
	// Buffer below is sized to a little more than twice as big as the largest allowed format,
	// which avoids having to constantly check for buffer overflow while translating aFormat
	// into format_buf:
	#define FT_MAX_OUTPUT_CHARS (2*FT_MAX_INPUT_CHARS + 10)
	char format_buf[FT_MAX_OUTPUT_CHARS + 1];
	char output_buf[FT_MAX_OUTPUT_CHARS + 1]; // The size of this is somewhat arbitrary, but buffer overflow is checked so it's safe.

	char yyyymmdd[256] = ""; // Large enough to hold date/time and any options that follow it (note that D and T options can appear multiple times).

	SYSTEMTIME st;
	char *options = NULL;

	if (!*aYYYYMMDD) // Use current local time by default.
		GetLocalTime(&st);
	else
	{
		strlcpy(yyyymmdd, omit_leading_whitespace(aYYYYMMDD), sizeof(yyyymmdd)); // Make a modifiable copy.
		if (*yyyymmdd < '0' || *yyyymmdd > '9') // First character isn't a digit, therefore...
		{
			// ... options are present without date (since yyyymmdd [if present] must come before options).
			options = yyyymmdd;
			GetLocalTime(&st);  // Use current local time by default.
		}
		else // Since the string starts with a digit, rules say it must be a YYYYMMDD string, possibly followed by options.
		{
			// Find first space or tab because YYYYMMDD portion might contain only the leading part of date/timestamp.
			if (options = StrChrAny(yyyymmdd, " \t")) // Find space or tab.
			{
				*options = '\0'; // Terminate yyyymmdd at the end of the YYYYMMDDHH24MISS string.
				options = omit_leading_whitespace(++options); // Point options to the right place (can be empty string).
			}
			//else leave options set to NULL to indicate that there are none.

			// Pass "false" for validatation so that times can still be reported even if the year
			// is prior to 1601.  If the time and/or date is invalid, GetTimeFormat() and GetDateFormat()
			// will refuse to produce anything, which is documented behavior:
			YYYYMMDDToSystemTime(yyyymmdd, st, false);
		}
	}
	
	// Set defaults.  Some can be overridden by options (if there are any options).