d4file(4)

NAME
d4file - D4-format binary file

SYNOPSIS
d4file

DESCRIPTION
The universal file format for storing the list of 4-tuple data. The file is called "D4-format file". D4-format file consists of two parts. A header with 256byte data is put on the head of file; a magic number for recognizing file format, an attribute code, the number of data, lower- and higher-limit of data are held in the header. Data part follows the header; list of 4-tuple data, the quadruple of 2-byte-integers (short), are put in the data part. Bit- and byte-order are MSB-first (big-endian). The file header is defined by the following structure.

    struct d4file {
    	char	d4_magic[8];	/* = "DATA0004" */
    	int32	d4_attrb;	/* = 0 */
    	int32	d4_count;	/* = 0 */
    	short	d4_llimit[4];	/* lower  limit of each member */
    	short	d4_hlimit[4];	/* higher limit of each member */
    	short	d4_spc[48];	/* (filler) */
    };

d4_magic field is always filled with string "DATA0004". d4_attrb holds the attribute code of file. The attribute code is always 0. d4_count holds the number of 4-tuple data. If this field is not used, constant 0 is set. d4_llimit and d4_hlimit arrays hold lower- and higher-limits of 4-tuple data respectively. d4_spc array is a dummy field, which is filled with zeros.

Each 4-tuple data is defined by the following structure.

    struct d4pac {
    	short	d4_data[4];
    };

The real value held in d4_data can be either signed 2byte-integer (short) and unsigned 2byte-integer (unsigned short). The selection of the type depends on its application.

AUTHOR
Copyright (C) 1995-1997 Hideaki Goto E-Mail: hgot@ecip.tohoku.ac.jp, hgot@aso.ecei.tohoku.ac.jp