/*
 * printhex.c
 * I)ruid <druid@caughq.org>
 *
 * Function to print a buffer as hex with ascii representations.
 *
 */

#include <stdio.h>
#include <ctype.h>


void printhex( unsigned char *buf, int size ) {
	int x, y;

	for( x=1; x<=size; x++ ) {

		if( x == 1 ) printf( "%04x  ", x-1 ); /* Print an offset line header */

		printf( "%02x ", buf[x-1] ); /* print the hex value */

		if( x % 8 == 0 ) printf( " " ); /* padding space at 8 and 16 bytes */

		if( x % 16 == 0 ) {
			/* We're at the end of a line of hex, print the printables */
			printf( " " );
			for( y = x - 15; y <= x; y++ ) {
				if( isprint( buf[y-1] ) ) printf( "%c", buf[y-1] ); /* if it's printable, print it */
				else printf( "." ); /* otherwise substitute a period */
				if( y % 8 == 0 ) printf( " " ); /* 8 byte padding space */
			} 
			if( x < size ) printf( "\n%04x  ", x ); /* Print an offset line header */
		}
	}
	x--;

	/* If we didn't end on a 16 byte boundary, print some placeholder spaces before printing ascii */
	if( x % 16 != 0 ) {
		for( y = x+1; y <= x + (16-(x % 16)); y++ ) {
			printf( "   " ); /* hex value placeholder spaces */
			if( y % 8 == 0 ) printf( " " ); /* 8 and 16 byte padding spaces */
		};

		/* print the printables */
		printf( " " );
		for( y = (x+1) - (x % 16); y <= x; y++ ) {
			if( isprint( buf[y-1] ) ) printf( "%c", buf[y-1] ); /* if it's printable, print it */
			else printf( "." ); /* otherwise substitute a period */
			if( y % 8 == 0 ) printf( " " ); /* 8 and 16 byte padding space */
		}
	}

	/* Done! */
	printf( "\n" );
}