1/***********************************************************************
2*                                                                      *
3*               This software is part of the ast package               *
4*          Copyright (c) 1985-2010 AT&T Intellectual Property          *
5*                      and is licensed under the                       *
6*                  Common Public License, Version 1.0                  *
7*                    by AT&T Intellectual Property                     *
8*                                                                      *
9*                A copy of the License is available at                 *
10*            http://www.opensource.org/licenses/cpl1.0.txt             *
11*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12*                                                                      *
13*              Information and Software Systems Research               *
14*                            AT&T Research                             *
15*                           Florham Park NJ                            *
16*                                                                      *
17*                 Glenn Fowler <gsf@research.att.com>                  *
18*                  David Korn <dgk@research.att.com>                   *
19*                   Phong Vo <kpv@research.att.com>                    *
20*                                                                      *
21***********************************************************************/
22#include	"sfhdr.h"
23
24/*	Set some control flags or file descript for the stream
25**
26**	Written by Kiem-Phong Vo.
27*/
28
29#if __STD_C
30int sfset(Sfio_t* f, int flags, int set)
31#else
32int sfset(f,flags,set)
33Sfio_t*		f;
34int		flags;
35int		set;
36#endif
37{
38	reg int	oflags;
39	SFMTXDECL(f);
40
41	SFMTXENTER(f,0);
42
43	if(flags == 0 && set == 0)
44		SFMTXRETURN(f, (f->flags&SF_FLAGS));
45
46	if((oflags = (f->mode&SF_RDWR)) != (int)f->mode && _sfmode(f,oflags,0) < 0)
47		SFMTXRETURN(f, 0);
48
49	if(flags == 0)
50		SFMTXRETURN(f, (f->flags&SF_FLAGS));
51
52	SFLOCK(f,0);
53
54	/* preserve at least one rd/wr flag */
55	oflags = f->flags;
56	if(!(f->bits&SF_BOTH) || (flags&SF_RDWR) == SF_RDWR )
57		flags &= ~SF_RDWR;
58
59	/* set the flag */
60	if(set)
61		f->flags |=  (flags&SF_SETS);
62	else	f->flags &= ~(flags&SF_SETS);
63
64	/* must have at least one of read/write */
65	if(!(f->flags&SF_RDWR))
66		f->flags |= (oflags&SF_RDWR);
67
68	if(f->extent < 0)
69		f->flags &= ~SF_APPENDWR;
70
71	/* turn to appropriate mode as necessary */
72	if((flags &= SF_RDWR) )
73	{	if(!set)
74		{	if(flags == SF_READ)
75				flags = SF_WRITE;
76			else	flags = SF_READ;
77		}
78		if((flags == SF_WRITE && !(f->mode&SF_WRITE)) ||
79		   (flags == SF_READ && !(f->mode&(SF_READ|SF_SYNCED))) )
80			(void)_sfmode(f,flags,1);
81	}
82
83	/* if not shared or unseekable, public means nothing */
84	if(!(f->flags&SF_SHARE) || f->extent < 0)
85		f->flags &= ~SF_PUBLIC;
86
87	SFOPEN(f,0);
88	SFMTXRETURN(f, (oflags&SF_FLAGS));
89}
90