#include	"defs.h"

/*
 * input output library
 *
 * S. R. Bourne
 * Bell Telephone Laboratories
 *
 */

openf(f, idf, chan)
	FILEPTR f;
	STRING idf;
	STRING chan;
{
	UFD r;

	IF any('r', chan)
	THEN	IF idf==nil(STRING) ORF *idf==0
		THEN	r = dup(0);
		ELSE	r = open(idf, 0);
		FI
		f->fstatus = F_READING;
		f->flin=1;
		f->fnxt=f->fbuf;
		f->fend=f->fbuf;

	ELIF any('w', chan)
	THEN	IF idf==nil(STRING) ORF *idf==0
		THEN	r = dup(1);
		ELSE	r=open(idf, 1);
			IF r<0 ANDF any('c', chan)
			THEN	r=creat(idf, 0666);
			FI
		FI
		f->fstatus = F_WRITING;
		f->flin=1;
		f->fnxt=f->fbuf;
		f->fend=f->fbuf+F_BUFSIZ;
	ELIF any('c', chan)
	THEN	r=creat(idf,0666);
	ELSE	r = -1;
	FI
	f->fdes = r;
	f->fsiz = F_BUFSIZ;
	return(r);
}

initf(f, fd)
	REG FILEPTR	f;
	UFD		fd;
{
	f->fdes=fd; f->fsiz=F_BUFSIZ;
	f->fnxt=f->fend=f->fbuf; f->flin=1;
	f->fstatus=F_READING;
}

estabf(f, s)
	REG FILEPTR	f;
	REG STRING	s;
{
	f->fdes = -1;
	f->fend=upbstr(s)+(f->fnxt=s);
	f->flin=1;
	f->fstatus=F_READING;
	IF s==nil(STRING) THEN f->fstatus |= F_EOF; FI
	return(s==0);
}

pushf(af)
	FILEPTR		af;
{
	REG FILEPTR	f;

	(f=af)->fstak=standin;
	standin=f;
}

popf()
{
	REG FILEPTR	f;

	IF (f=standin)->fstak
	THEN	IF f->fdes>=0 THEN close(f->fdes); FI
		standin=f->fstak;
		return(TRUE);
	ELSE	return(FALSE);
	FI
}

linepos(f)
	FILEPTR f;
{
	return(f->flin);
}

setline(f)
	FILEPTR f;
{
	f->flin=1;
}

closef(f)
	FILEPTR	f;
{
	IF f->fdes >= 0
	THEN	close(f->fdes);
		f->fdes = -1;
	FI
}

setfile(f, tab)
	FILEPTR	f;
	CHAR	*tab;
{
	/* set up translation table for file */

	f->ftab=tab;
}

charpos(f)
	REG FILEPTR f;
{
	return(f->fnxt-f->fbuf);
}

setmode(f, s)
	FILEPTR	f;
	STRING	s;
{
	/* set mode for output
	 * t => convert tabs
	 * s => strip blanks
	 * u => upper case output only
	 */
	REG CHAR c;

	WHILE c = *s++
	DO	SWITCH c IN

		case 't':	f->fstatus |= F_TABCVT;
				break;

		case 's':	f->fstatus |= F_SBLANK;
				break;

		case 'u':	f->fstatus |= F_UPPER;
				break;

		ENDSW
	OD
}