#!/bin/ksh

# -----------------------------------------------------------------------
# Filename:   dumpdata.ksh
# Purpose:    Dump first record of binary file according to C-language 
#             definition to see if the data and layout match.
# Author:     Frank Naude, Oracle FAQ
# -----------------------------------------------------------------------

DATAFILE=y.data		# Binary data file
MAPFILE=y.map		# Map file - C field definitions (see sample below)
STARTPOS=16		# Offset of fist record in DATAFILE

cat $MAPFILE | while read line
do
  X=`echo $line | cut -d\[ -f 2`
  FLD=`echo $line | cut -d\[ -f 1`	# get variable name
  BYTES=`echo $X | cut -d\] -f 1`	# get variable length

  # Map the variable to the data file...
  VAL=`od -j $STARTPOS -N $BYTES -c $DATAFILE | cut -c11- | tr -s '\t' ' '`

  echo "$FLD len=$BYTES val=[$VAL]"
  ((STARTPOS=STARTPOS+BYTES))
done

VAL=`od -j $STARTPOS -N 20 -c $DATAFILE | cut -c11- | tr -s '\t' ' '`
echo "First 20 bytes of 2nd record = [$VAL]"


# Sample MAPFILE:
# ---------------
#    char rowid[18];
#    char ename[6];
#    unsigned char sal[8];
#    unsigned char comm[8];
#    char car_reg[8];
#