/*
 *  LIBML library - read, write and manipulate MATLAB MAT-files
 *  Copyright (C) 1994 Michael J. Maurer
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *  Michael Maurer <maurer@nova.stanford.edu>
 *  Durand Bldg - Room 232
 *  Stanford, CA 94305-4055
 *  (415) 723-1024
 */
/******************************************************************************
  mlmisc.c

Some utility routines for handling matlab MAT files.

Copyright (c) 1993 by Michael Maurer (maurer@nova.stanford.edu).
******************************************************************************/
/* $Log$ */
#include <stdio.h>
#include "libml.h"
#include "libml.p"
#include "libmisc.h"


/******************************************************************************
  fcopyn

Copies L bytes from opened stream f1 to opened stream f2.
Returns nonzero on error.
******************************************************************************/

int
fcopyn(f1,f2,L)
FILE *f1,*f2;
long L;
{
   static char buf[BUFSIZ];
   int err=0,nb;

   while (L>BUFSIZ && !err) {
      err|=((nb=fread(buf,sizeof(char),BUFSIZ,f1))!=BUFSIZ);
      err|=(fwrite(buf,sizeof(char),nb,f2)!=nb);
      L-=nb;
   }
   if (L>0 && !err) {
      err|=((nb=fread(buf,sizeof(char),L,f1))!=L);
      err|=(fwrite(buf,sizeof(char),nb,f2)!=nb);
   }
   return err;
}

/******************************************************************************
  mlcopy

Copies a single Matlab-format object in fin to fout.

If an error occurs, a nonzero value is returned, fin remains as it was
after the error, but fout is seeked back to its position on entry.
******************************************************************************/

int
mlcopy(fin,fout)
FILE *fin,*fout;
{
   int type,mrows,ncols,imagf,M,O,P,T,err;
   long dsize,offset;
   char pname[80];
#ifdef __STDC__
   fpos_t fpos;
#else
   long fpos;
#endif

   if (err=mlreadh(fin, &type, pname, &mrows, &ncols, &imagf)) {
      fprintf(stderr,"[mlcopy] mlreadh returned %d\n",err);
      return 1;
   }
   dsize=mltype(type, &M, &O, &P, &T);
   offset = dsize*mrows*ncols;
   if (imagf) offset *= 2;
#ifdef __STDC__
   if (fgetpos(fout,&fpos)) {
      fprintf(stderr,"[mlcopy] fgetpos failed\n");
      return 2;
   }
#else
   if (fpos=ftell(fout)) {
      fprintf(stderr,"[mlcopy] ftell failed\n");
      return 2;
   }
#endif
   if (err=mlwriteh(fout, type, pname, mrows, ncols, imagf)) {
      fprintf(stderr,"[mlcopy] mlwriteh returned %d\n",err);
#ifdef __STDC__
      if (fsetpos(fout,&fpos)) {
         fprintf(stderr,"[mlcopy] fsetpos failed\n");
         return 3;
      } 
#else   
      if (fseek(fout,fpos,SEEK_SET)) {
         fprintf(stderr,"[mlcopy] fseek failed\n");
         return 3;
      }
#endif
      return 4;
   }
   if (fcopyn(fin,fout,offset)) {
      fprintf(stderr,"[mlcopy] write failed\n");
#ifdef __STDC__
      if (fsetpos(fout,&fpos)) {
         fprintf(stderr,"[mlcopy] fsetpos failed\n");
         return 5;
      }
#else
      if (fseek(fout,fpos,SEEK_SET)) {
         fprintf(stderr,"[mlcopy] fseek failed\n");
         return 5;
      }
#endif
      return 6;
   }
   return 0;
}


/******************************************************************************
  mlskip

Skips forward a single Matlab-format object in fin.

Returns nonzero on failure.
******************************************************************************/

int
mlskip(fin)
FILE *fin;
{
   int type,mrows,ncols,imagf,M,O,P,T,err;
   long dsize,offset;
   char pname[80];

   if (err=mlreadh(fin, &type, pname, &mrows, &ncols, &imagf)) {
      fprintf(stderr,"[mlskip] mlreadh returned %d\n",err);
      return 1;
   }
   dsize=mltype(type, &M, &O, &P, &T);
   offset = dsize*mrows*ncols;
   if (imagf) offset *= 2;
   if (fseek(fin, offset, SEEK_CUR)) {
      fprintf(stderr,"[mlskip] seek failed\n");
      return 2;
   }
   return 0;
}