/* XSum2.c - sums up all bytes in a compressed or uncompressed file 
 *           without reading the whole file at once into mem
 *
 * This is a typical read-and-process xpk application. Try it out... XSum a
 * file, then compress it and XSum it again. The result should be the same.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <libraries/xpk.h>

struct Library *XpkBase, *OpenLibrary( char *libName, ULONG version );

char   errbuf[XPKERRMSGSIZE+1];
UBYTE *outbuf;
long  outbuflen;

void end( char *text )
{
	if( outbuf )  FreeMem(outbuf,outbuflen);
	if( text )    Write(Output(), text, strlen(text));
	if( XpkBase ) CloseLibrary( XpkBase );
	exit(text ? 10 : 0);
}

void main(int argc, char *argv[])
{
	XFH*   xfh;
	LONG   len, sum=0;
	UBYTE* ptr, *last;

	if( argc!=2 )
		end("Usage: xSum <filename>\n");

	if(!(XpkBase=OpenLibrary( XPKNAME,0)))
		end("Cannot open "XPKNAME"\n");

	if(XpkOpenTags( &xfh, XPK_InName,argv[1], XPK_PassThru,TRUE, TAG_DONE ))
		end(strcat(errbuf,"\n"));

	if( !(outbuf=(UBYTE*)AllocMem( outbuflen=xfh->NLen+XPK_MARGIN,0)))
		end("Out of memory\n");

	while( (len=XpkRead(xfh, outbuf, XPKLEN_ONECHUNK ))>0 ) {
		ptr = (UBYTE*)outbuf;
		last= ptr +   len;
		while( ptr<last )
			sum+=*ptr++;
	}

	if( XpkClose(xfh) || len )
		end(strcat(errbuf,"\n"));

	printf("%d\n",sum);

	end(NULL);
}