num_files.i4.v = sr_directory_info_c( [,file_number.i4.v]

	This routine returns directory information for save/restore files.
	It returns the number of files found.

	dir_data	returned directory information
			(structure type is either SR_DIR_INFO or
			 SR_DIR_INFO_FULL depending on the value of
			 "full_info") (Note: If a value of NULL is passed,
			 only the number of files found will be returned.)
	[file_number]	desired file number (If this is specified and has
			a value greater than or equal to zero, only
			information for that file number will be returned.)
			(default is SRMNGR_ALL_FILES which will result in the
			 return of information for all files of the
			 requested category)
	[category]	type of files to display
			If the data source is SRMNGR_NORMAL, this argument
			determines which supersystem's files to display.
			(SR_GLOBAL -> global supersystem (default),
			 SR_LINAC -> Linac supersystem,
			 SR_BOOSTER -> Booster supersystem,
			 SR_MAININJECTOR -> Main Injector supersystem,
			 SR_EXTERNALBEAMS -> external beams supersystem,
			 SR_TEVATRON -> Tevatron supersystem,
			 SR_MUON -> Muon supersystem,
			 SR_FRIG -> refrigerator supersystem,
			 SR_MISC -> miscellaneous supersystem,
			 SR_ARCHIVE -> archive supersystem,
			 SR_RECYCLER -> Recycler supersystem,
			 SR_SHOTS -> shots supersystem,
			 SR_CIRCULAR -> circular supersystem,
			 SR_MINIBOONE -> MiniBooNE supersystem,
			 SR_NUMI -> NuMI supersystem,
			 SR_PXIE -> PXIE supersystem,
			 SR_NML -> NML supersystem,
			 SR_MTA -> MTA (Muon Test Area) supersystem,
			 SR_SYCONFIG -> Switchyard configuration supersystem,
			 SR_CMTF -> CMTF supersystem,
			 SR_ALL_SYSTEMS -> all supersystems,
			 SRMNGR_IMPLICIT_CATEGORY -> supersystem is calculated
						     from the file number,
			 CLIB_DEFAULT_ARG -> previously selected supersystem)
			If the data source is SRMNGR_SDA_DATA, this argument
			allows choosing between normal and archived files.
			(SR_SDA_NORMAL -> select normal SDA files (default),
			 SR_SDA_FROM_TAPE -> SDA data from archive tapes,
			 SR_SDA_ARCHIVE_BASE + n -> SDA archive directory
						    on disk,
			 CLIB_DEFAULT_ARG -> previously selected directory)
	[data_source]	source of data
			(CLIB_DEFAULT_ARG -> use previously selected source
			 SRMNGR_NORMAL -> normal save/restore files,
			 SRMNGR_SDA_DATA -> SDA data)
	[full_info]	determines the type of information returned
			(TRUE -> returns complete file information in
				 SR_DIR_INFO_FULL structures,
			 FALSE -> returns abbreviated information in
				  SR_DIR_INFO structures (default))
	[sda_usage]	null terminated SDA usage string (This argument only
			has meaning if the data source is SDA.)
			(default is NULL)
	[max_return]	maximum number of entries to return
			(default is SRMNGR_ALL_FILES)

	This function returns status values as follows:

	DIO_BADARG		invalid data source or category
	DIO_MEMFAIL		dynamic memory allocation failure
	SAV_RST_xxx		Save/restore error
	otherwise		number of files found

	This function requires the following include files:

	cns_data_structs_h, cbslib_h, acnet_errors_h

	Related functions:

	sr_directory_info_by_date_c, sr_set_source_c, sr_file_menu_c,
	sr_category_menu_c, sr_sda_select_directory_c, sr_sda_set_directory_c,
	sr_sda_file_number_c, sr_sda_store_number_c, sr_sda_store_times_c,
	sr_disconnect, sr_sda_cases_present_c, sr_sda_subcases_present_c,

	C/C++ usage:

	char	*sda_usage = (char *) NULL;
	int	num_files;
	int	file_number = SRMNGR_ALL_FILES;
	int	category = SR_GLOBAL;
	int	data_source = SRMNGR_NORMAL;
	int	full_info = FALSE;
	int	max_return = SRMNGR_ALL_FILES;

	num_files = sr_directory_info_c(dir_data,file_number,category,