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CPM OPERATING SYSTEMS/CPM 68K/1.2 SOURCE/6/FILESZ.C

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+/**********************************************************************
+*
+* 		_ f i l e s z   f u n c t i o n
+* 		-------------------------------
+*	Copyright 1982 by Digital Research Inc.  All rights reserved.
+*
+*	This routine computes the size of a CP/M file, and leaves the fd
+*	pointing to the end of file.  
+*	Note that the file must have been previously opened.
+*
+*	Calling sequence:
+*		size = _filesz(fd)
+*	where:
+*		size =	# bytes in file;
+*			0 if not disk file;
+*			-1 if I/O error
+*		fd   = file descriptor returned by open.
+*
+***********************************************************************/
+
+#include "portab.h"
+#include "osif.h"
+#include "osiferr.h"
+#include "errno.h"
+
+LONG _filesz(fd)				/****************************/
+	WORD fd;				/* file descriptor	    */
+{
+	REG	FD	*fp;			/* file's ccb pointer	    */
+	REG	BYTE	*p1, *p2;		/* temps for buffer work    */
+	REG	LONG	xsector;		/* where we are in file	    */
+		FD	*_chkc();		/* cvt & check fd to fp	    */
+	REG	WORD	xuser;			/* Current user #	    */
+						/****************************/
+	if((fp = _chkc(fd)) == NULLFD)		/* Convert to pointer	    */
+		return(FAILURE);		/*  Can't: EBADF	    */
+	if(fp->flags&(ISTTY|ISLPT))		/* Non disk file?	    */
+		return(0);			/*			    */
+#if PCDOS /*================================================================*/
+	fp->offset = (fp->fcb).fcb_filsiz;	/* simple, eh?		    */
+#endif    /*================================================================*/
+
+#if CPM   /*================================================================*/
+
+    if( fp->flags & DIRTY ) {			/* File been used?	    */
+	fp->offset = fp->hiwater;		/* yes: this must be right  */
+    } else {					/****************************/
+	xuser = _chkuser(fp->user);		/* Check user # for change  */
+	__OSIF(FILSIZ,&(fp->fcb));		/* Do BDOS call		    */
+	_uchkuser(fp->user,xuser);		/* Change back if needed    */
+#if HILO					/*--------------------------*/
+	fp->fcb.record &= 0xFFFFFFL;		/* mask off cr byte	    */
+	xsector = fp->fcb.record - 1;		/* last sector in file	    */
+#else						/*--------------------------*/
+	xsector = (fp->fcb.record >>8) - 1;	/* last sector in file      */
+#endif						/*--------------------------*/
+	if( fp->flags & ISASCII )		/****************************/
+	{					/* Ascii file: posit to EOF */
+	  if(xsector >= 0)			/* if any size at all	    */
+	  {					/*	*********************/
+	    if( xsector != fp->sector )		/* need to change sector?   */
+	    {					/* get correct sector********/
+	      if((fp->flags & DIRTY) != 0)	/* Something to write 1st?  */
+	      {					/*			    */
+	        if(_blkio(fp,fp->sector,fp->buffer, /* Write out	    */
+		  1L,B_WRITE) != 1)		/*	the buffer	    */
+		    RETERR(FAILURE,EIO);	/*			    */
+	        fp->flags &= ~DIRTY;		/* turn off this bit	    */
+	      }					/*			    */
+	      if(_blkio(fp,xsector,fp->buffer,	/* scan this last sector    */
+		  1L,B_READ) != 1)		/*    for EOFCHAR	    */
+	        RETERR(FAILURE,EIO);		/*			    */
+	    }					/* got correct sector********/
+	    fp->sector = xsector;		/* 			    */
+	    fp->offset = xsector << 7;		/*   			    */
+	    p1 = &(fp->buffer[0]);		/* start of buf		    */
+	    p2 = &(fp->buffer[SECSIZ]);		/* end of buf		    */
+	    while( p1<p2  &&  *p1 != EOFCHAR)	/* look for EOFCHAR	    */
+		p1++;				/*			    */
+	    fp->offset += p1-&(fp->buffer[0]);	/* update offset to EOF	    */
+	  }					/*	*********************/
+	  else fp->offset=0;			/* o.w. beginning of file   */
+						/****************************/
+	} else {				/* Binary file:compute size */
+	  fp->offset = (xsector+1) << 7;	/* set to end of last record*/
+	}					/****************************/
+    }						/****************************/
+#endif    /*================================================================*/
+    fp->hiwater = fp->offset;			/* whatever happened, set it*/
+    fp->flags |= ATEOF;				/* make sure they know	    */
+    return(fp->offset);				/* this is it		    */
+}						/****************************/
+w	    */
+    return(fp->offset);				/* this is it		    */
+}						/****************************/
+w	    */
+    return(fp->offset);				/* this is it		    */
+}						/****************************/