1*4887Schin /***********************************************************************
2*4887Schin *                                                                      *
3*4887Schin *               This software is part of the ast package               *
4*4887Schin *           Copyright (c) 1985-2007 AT&T Knowledge Ventures            *
5*4887Schin *                      and is licensed under the                       *
6*4887Schin *                  Common Public License, Version 1.0                  *
7*4887Schin *                      by AT&T Knowledge Ventures                      *
8*4887Schin *                                                                      *
9*4887Schin *                A copy of the License is available at                 *
10*4887Schin *            http://www.opensource.org/licenses/cpl1.0.txt             *
11*4887Schin *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12*4887Schin *                                                                      *
13*4887Schin *              Information and Software Systems Research               *
14*4887Schin *                            AT&T Research                             *
15*4887Schin *                           Florham Park NJ                            *
16*4887Schin *                                                                      *
17*4887Schin *                 Glenn Fowler <gsf@research.att.com>                  *
18*4887Schin *                  David Korn <dgk@research.att.com>                   *
19*4887Schin *                   Phong Vo <kpv@research.att.com>                    *
20*4887Schin *                                                                      *
21*4887Schin ***********************************************************************/
22*4887Schin #include	"sfhdr.h"
23*4887Schin 
24*4887Schin /*	Set some control flags or file descript for the stream
25*4887Schin **
26*4887Schin **	Written by Kiem-Phong Vo.
27*4887Schin */
28*4887Schin 
29*4887Schin #if __STD_C
30*4887Schin int sfset(reg Sfio_t* f, reg int flags, reg int set)
31*4887Schin #else
32*4887Schin int sfset(f,flags,set)
33*4887Schin reg Sfio_t*	f;
34*4887Schin reg int		flags;
35*4887Schin reg int		set;
36*4887Schin #endif
37*4887Schin {
38*4887Schin 	reg int	oflags;
39*4887Schin 
40*4887Schin 	SFMTXSTART(f,0);
41*4887Schin 
42*4887Schin 	if(flags == 0 && set == 0)
43*4887Schin 		SFMTXRETURN(f, (f->flags&SF_FLAGS));
44*4887Schin 
45*4887Schin 	if((oflags = (f->mode&SF_RDWR)) != (int)f->mode && _sfmode(f,oflags,0) < 0)
46*4887Schin 		SFMTXRETURN(f, 0);
47*4887Schin 
48*4887Schin 	if(flags == 0)
49*4887Schin 		SFMTXRETURN(f, (f->flags&SF_FLAGS));
50*4887Schin 
51*4887Schin 	SFLOCK(f,0);
52*4887Schin 
53*4887Schin 	/* preserve at least one rd/wr flag */
54*4887Schin 	oflags = f->flags;
55*4887Schin 	if(!(f->bits&SF_BOTH) || (flags&SF_RDWR) == SF_RDWR )
56*4887Schin 		flags &= ~SF_RDWR;
57*4887Schin 
58*4887Schin 	/* set the flag */
59*4887Schin 	if(set)
60*4887Schin 		f->flags |=  (flags&SF_SETS);
61*4887Schin 	else	f->flags &= ~(flags&SF_SETS);
62*4887Schin 
63*4887Schin 	/* must have at least one of read/write */
64*4887Schin 	if(!(f->flags&SF_RDWR))
65*4887Schin 		f->flags |= (oflags&SF_RDWR);
66*4887Schin 
67*4887Schin 	if(f->extent < 0)
68*4887Schin 		f->flags &= ~SF_APPENDWR;
69*4887Schin 
70*4887Schin 	/* turn to appropriate mode as necessary */
71*4887Schin 	if((flags &= SF_RDWR) )
72*4887Schin 	{	if(!set)
73*4887Schin 		{	if(flags == SF_READ)
74*4887Schin 				flags = SF_WRITE;
75*4887Schin 			else	flags = SF_READ;
76*4887Schin 		}
77*4887Schin 		if((flags == SF_WRITE && !(f->mode&SF_WRITE)) ||
78*4887Schin 		   (flags == SF_READ && !(f->mode&(SF_READ|SF_SYNCED))) )
79*4887Schin 			(void)_sfmode(f,flags,1);
80*4887Schin 	}
81*4887Schin 
82*4887Schin 	/* if not shared or unseekable, public means nothing */
83*4887Schin 	if(!(f->flags&SF_SHARE) || f->extent < 0)
84*4887Schin 		f->flags &= ~SF_PUBLIC;
85*4887Schin 
86*4887Schin 	SFOPEN(f,0);
87*4887Schin 	SFMTXRETURN(f, (oflags&SF_FLAGS));
88*4887Schin }
89