The Postman's Sort

Listing 5 (key.h)

/*
Postman's Sort (R) Version 1.0
Copyright (c) Robert Ramey 1991. All Rights Reserved
*/

/*********************************************************************
data structure for collating sequence values
**********************************************************************/
typedef struct {
   unsigned int
      order,                             /* highest value in table */
      value[256];         /* table of weights for 256 possible bytes */
} SEQ;

/*********************************************************************
data structure and storage for holding keys as specified in the
command line
**********************************************************************/

                                       /* structure for a key */
typedef struct {
   unsigned int rfield;              /* index of field within record */

   unsigned int disp;         /* starting point of key with in field */
   unsigned int size;                         /* maximum size of key */
   unsigned int key_type;          /* flag to indicate type of field */
   BOOLEAN inverted;       /* reverse the sense of sort for this key */
   SEQ *seq;             /* pointer to structure of collating values */
} KEY;

#define DEFAULT 0                /* default type of alphanumeric key */
#define SIGN 1                       /* an optional 1 character sign */
#define NUMERIC 2            /* digits to be expanded to fixed width */
#define FRACTION 3                    /* fractional part of a number */

extern KEY key[];         /* table of keys specified in command line */
extern unsigned int
   key_count,                                      /* number of keys */
   tab_count;
extern size_t
   *tab,
   data_offset,
   record_offset;
#define blk_offset (record_offset-1)
/* End of File */