/* XSum.c - sums up all bytes in a compressed or uncompressed file
 *
 * 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 <proto/exec.h>
#include <proto/dos.h>
#include <proto/xpk.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

struct Library *XpkBase = NULL;

char errbuf[XPKERRMSGSIZE + 1], *outbuf = NULL;
long outlen, 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[])
{
  UBYTE *ptr, *last;
  ULONG sum = 0;

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

  if (argc != 2)
    end ("Usage: XChecksum filename\n");

  if (XpkUnpackTags (
		      XPK_InName, argv[1],	/* The file name to be read              */
		      XPK_GetError, errbuf,	/* A pointer to the error message buffer */
		      XPK_GetOutBuf, &outbuf,	/* Sets a pointer to the output buffer   */
		      XPK_GetOutLen, &outlen,	/* Sets the number of bytes written      */
		      XPK_GetOutBufLen, &outbuflen,	/* Sets the length of the output buffer  */
		      XPK_PassThru, TRUE,	/* Will pass through uncompressed data   */
		      TAG_DONE
      ))
    end (strcat (errbuf, "\n"));

  ptr = (UBYTE *) outbuf;
  last = ptr + outlen;
  while (ptr < last)
    sum += *ptr++;
  printf ("%d\n", sum);

  end (NULL);
}