/*
	writes a nice looking hex-dump with ascii printable chars on the right.
	this is for debugging purposes really.
	
	mem is the buffer to print
	num is the number of bytes to print out.
*/

void print_hex(FILE *out, unsigned char *mem, unsigned int num)
{
	if(!out)
	{
		#if DEBUG
		logit(LOG_WARN,__FILE__,__LINE__,"found 'out' to be null");
		#endif
		return;	
	}
	if(!mem)
	{
		#if DEBUG
		logit(LOG_WARN,__FILE__,__LINE__,"found 'mem' to be null");
		#endif
		return;	
	}
	if(num < 1)
		return;
	
	const unsigned int bytes_per_row=16;
		
	unsigned int numlines = num / bytes_per_row;
	unsigned int numbytes = num % bytes_per_row;
	unsigned int offset   = 0;
	unsigned int curline  = 0;
	unsigned int curbyte  = 0;
	unsigned char *data   = mem;
	char *hexbuff         = calloc(1,(bytes_per_row*3) + 1);
	if(!hexbuff)
	{
		logit(LOG_ERROR,__FILE__,__LINE__,"cannot calloc memory for hexbuff");
		return;	
	}
	char *hexptr=hexbuff;
	
	char *asciibuff       = calloc(1,bytes_per_row+1);
	if(!asciibuff)
	{
		logit(LOG_ERROR,__FILE__,__LINE__,"cannot calloc memory for asciibuff");
		free(hexbuff);
		return;	
	}
	char *ascptr=asciibuff;
	
	
	logit(LOG_DEBUG,__FILE__,__LINE__,"print_hex printing %d lines and %d bytes",numlines,numbytes);
	
	for(curline = 0;curline < numlines;curline++)
	{
		//print a beginning of the row, which is like this:
		//00000000h: "
		fprintf(out,"%08Xh: ",offset);
		offset+=bytes_per_row;	
		hexptr=hexbuff;
		ascptr=asciibuff;
		for(curbyte = 0;curbyte < bytes_per_row;curbyte++)
		{
			//first, print the hex char.
			sprintf(hexptr,"%02X ",(unsigned int)*data);
			
			//now print ascii variant, if it's printable
			if(*data >=32 && *data < 126)
				sprintf(ascptr,"%c ",(unsigned char)*data);
			else
				sprintf(ascptr,". ");
			
			data++; //move to hex byte in memory
			hexptr+=3; //three bytes for each hex char (XX )
			ascptr++;  //one byte for ascii chars.
		}
		//now, print this row out to the stream.
		fprintf(out,"%s; %s\n",hexbuff,asciibuff);
	}
	
	//now, we need to print any bytes which didn't quite make it
	//for a full line.
	hexptr=hexbuff;
	ascptr=asciibuff;
	fprintf(out,"%08Xh: ",offset);
	int leftover = (bytes_per_row - numbytes) * 3 - 1;
	
	for(curbyte = 0;curbyte < numbytes;curbyte++)
	{
		//first, print the hex char.
		sprintf(hexptr,"%02X ",(unsigned int)*data);
			
		//now print ascii variant, if it's printable
		if(*data >=32 && *data < 126)
			sprintf(ascptr,"%c ",(unsigned char)*data);
		else
			sprintf(ascptr,". ");
		
		data++; //move to hex byte in memory
		hexptr+=3; //three bytes for each hex char (XX )
		ascptr++;  //one byte for ascii chars.	
	}
	//now, print this row out to the stream.
	fprintf(out,"%s ",hexbuff);
	for(curbyte=0;curbyte<leftover;curbyte++)
	{
		fprintf(out," ");	
	}
	fprintf(out,"; %s",asciibuff);
	
	free(hexbuff);
	free(asciibuff);
	
	return;
}