/***************************************************************************
 *									    
 *			  _ t t y i n   F u n c t i o n			    
 *			  -----------------------------			    
 *	Copyright 1982 by Digital Research Inc.  All rights reserved.	    
 *									    
 *	Function "_ttyin" is used to read a line from the terminal.  	    
 *	It looks for the ISSPTTY flag set in the ccb: if set, it assumes    
 *	the fcb really contains sgttyb information (see <sgtty.h>), and	    
 *	behaves accordingly.						    
 *	Otherwise, it grabs up to a line at a time from the BDOS.	    
 *									    
 *	Calling Sequence:						    
 *		ret = _ttyin(fp,buffer,bytes);				    
 *	Where:								    
 *		fp	-> ccb pointer & channel info			    
 *		buffer	-> the user's input buffer			    
 *		bytes	=  the (maximum) number of bytes to read	    
 *		ret 	=  the number of bytes actually read		    
 *									    
 *	Modified:
 *		2/84 whf: conditionally compile RAWIO code  
 *		10/83 whf: eliminate static data (ttybuf), use _ttyinraw()   
 *									    
 ****************************************************************************/

#include "portab.h"
#include "osif.h"
#include "sgtty.h"
#define Bytesized 0xFF

WORD	_ttyin(fp,buff,bytes)			/****************************/
	FD	*fp;				/* -> filedes		    */
REG	BYTE	*buff;				/* -> user's buffer	    */
	UWORD	bytes;				/* =  requested byte count  */
{						/****************************/
REG	BYTE	*p;				/* Temp pointer		    */
	BYTE	ttybuf[Bytesized+2];		/* Biggest line from tty    */
	UWORD	xbytes,				/* Returned byte count	    */
		nbs;				/* Number to read	    */
LOCAL	struct sgttyb *tyb;			/* TTY info ptr (at fp->fcb)*/
						/*			    */
	if(fp->flags & ISSPTTY)			/* is this a special tty?   */
	{					/****************************/
/****************************************************************************/
#ifdef RAWIO
		tyb = &(fp->fcb);		/* assume info stored here  */
		if(tyb->sg_flags & RAW)		/* are we in raw mode?	    */
		{				/*			    */
		    *buff = _ttyinraw();	/* grab a char		    */
		    return(1);			/* return number bytes read */
		}				/*   ************************/
		if(tyb->sg_flags & CBREAK)	/* are we half baked?	    */
		{				/*			    */
		    p = buff;			/* use ptr		    */
		    *p = _ttyinraw();		/* get char		    */
		    if( *p == tyb->sg_kill )	/* kill char typed?	    */
			exit(1);		/*  yes: DIE, PROGRAM!	    */
		    if(tyb->sg_flags & LCASE)	/* they want lower case?    */
			*p = (*p>='A'&& *p<='Z' /*			    */
			  ? *p+('a'-'A') : *p);	/*  give them lower case    */
		    if((tyb->sg_flags & CRMOD)	/* xlate returns?	    */
		      && *p == '\r' )		/*			    */
		    {				/*			    */
			if(tyb->sg_flags & ECHO)/*			    */
			    __OSIF(CONIO,*p);	/* out before xlate	    */
			*p = '\n';		/*  yes, do xlation	    */
		    }				/*			    */
		    if(tyb->sg_flags & ECHO)	/* echo chars?		    */
			__OSIF(CONIO,*p);	/*			    */
		    return(1);			/* return number read	    */
		}				/*   ************************/
/****************************************************************************/
#else
		    _optoff("Raw I/O");
#endif
/****************************************************************************/
						/* nothing really special...*/
	}					/****************************/
	nbs = bytes < Bytesized ? bytes : Bytesized;/* don't read more than */
	ttybuf[0] = nbs;			/* asked for/we have room fr*/
	if (nbs == 1) 				/* then use conin not rdln  */
	  {
	    ttybuf[2] = __OSIF(CONIN,0);
	    ttybuf[1] = 1;
	    if (ttybuf[2] == '\r')
	      ttybuf[1] = 0;
	  }
	else
	  __OSIF(CONBUF,ttybuf);		/* Read line from BDOS	    */
						/****************************/
	xbytes = ttybuf[1] & 0xff;		/* # characters read	    */
	if( xbytes<nbs )			/* # read < #asked for,assum*/
		__OSIF(CONOUT,'\n');		/*   CR/LF line terminated  */
	p = &ttybuf[2];				/* p -> First character	    */
	while( bytes > 0 && xbytes > 0)		/* 			    */
	{					/* Copy 1 byte / time	    */
		if(*p == EOFCHAR)		/* ^Z typed?		    */
		{				/* Yes,			    */
			fp->flags |= ATEOF;	/*	Mark with EOF	    */
			break;			/*	Exit now	    */
		}				/****************************/
		*buff++ = *p++;			/*			    */
		bytes--;			/* Decrement request	    */
		xbytes--;			/* Decrement bytes in buff  */
	}					/****************************/
	if(bytes > 0)				/* Terminate on count?	    */
	{					/*			    */
		*buff++ = '\n';			/* No, plug in newline	    */
		p++;				/* Bump pointer		    */
	}					/****************************/
	return((WORD)(p-&ttybuf[2]));		/* Return # bytes moved	    */
}						/****************************/