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CPM OPERATING SYSTEMS/CPM 68K/1.0X SOURCES/v102a/clib/write.c

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+/***************************************************************************
+ *									    
+ *			   W r i t e   F u n c t i o n			    
+ *			   ---------------------------			    
+ *	Copyright 1982 by Digital Research Inc.  All rights reserved.	    
+ *									    
+ *	Function "write" simulates the UNIX write system call.  Any 	    
+ *	arbitrary number of bytes are written to the file specified by file 
+ *	descriptor.  No special alignment of file or buffer is required.    
+ *									    
+ *	Calling Sequence:						    
+ *		ret = write(fd,buffer,bytes);				    
+ *	Where:								    
+ *		fd	is an open file descriptor			    
+ *		buffer	is the buffer address				    
+ *		bytes	is the number of bytes to be written		    
+ *		ret	is the number of bytes actually written		    
+ *									    
+ *	Modifications:							    
+ *		11-Dec-83 whf	PC-DOS mods, divide out _wrtasc & _wrtbin.  
+ *		30-Nov-83 whf	Fix _wrtbin() boundary condition bug	    
+ *		19-Oct-83 whf	Separate out _wrtchr(), _ttyout(), _lstout()
+ *									    
+ ****************************************************************************/
+#include "portab.h"
+#include "osif.h"
+#include "osiferr.h"
+#include "errno.h"
+
+UWORD	write(fd,buff,bytes)			/* CLEAR FUNCTION ***********/
+						/*			    */
+	WORD		fd;			/* File descriptor	    */
+	BYTE		*buff;			/* Buffer address	    */
+	UWORD		bytes;			/* Number of bytes to xfer  */
+						/*			    */
+{						/****************************/
+	REG	FD	*fp;			/* File (ccb) pointer	    */
+	EXTERN	FD  	*_chkc();		/* fd -> fp Convertor	MGL */
+		UWORD	_wrtchr();		/* Device write routine     */
+		UWORD	_wrtasc();		/* Ascii write routine      */
+		UWORD	_wrtbin();		/* Binary write routine     */
+						/****************************/
+	if((fp=_chkc(fd)) == NULLFD)	        /* Get CCB address MGL	    */
+		return(FAILURE);		/*	Can't: EBADF	    */
+						/* note: bytes is unsigned  */
+	if(bytes == 0)				/* Trying to write 0 	    */
+		return(0);			/* Yes, a wise guy!	    */
+						/*			    */
+	if((fp->flags & ISREAD) != 0)		/* Check for readonly file  */
+		RETERR(FAILURE,EBADF);		/* Barf if so		    */
+						/****************************/
+	if( fp->flags & (ISTTY+ISLPT+ISQUE))	/* TTY, LST or QUE File?    */
+		return(_wrtchr(fp,buff,bytes));	/*	Yes, handle it	    */
+						/****************************/
+	if(fp->flags & ISASCII)			/* If ascii file	    */
+		return(_wrtasc(fp,buff,bytes)); /* do ascii style	    */
+	else	return(_wrtbin(fp,buff,bytes)); /* do binary style	    */
+}						/****************************/