xref: /titanic_44/usr/src/lib/libast/common/sfio/sfset.c (revision 3e14f97f673e8a630f076077de35afdd43dc1587)
1da2e3ebdSchin /***********************************************************************
2da2e3ebdSchin *                                                                      *
3da2e3ebdSchin *               This software is part of the ast package               *
4*3e14f97fSRoger A. Faulkner *          Copyright (c) 1985-2010 AT&T Intellectual Property          *
5da2e3ebdSchin *                      and is licensed under the                       *
6da2e3ebdSchin *                  Common Public License, Version 1.0                  *
77c2fbfb3SApril Chin *                    by AT&T Intellectual Property                     *
8da2e3ebdSchin *                                                                      *
9da2e3ebdSchin *                A copy of the License is available at                 *
10da2e3ebdSchin *            http://www.opensource.org/licenses/cpl1.0.txt             *
11da2e3ebdSchin *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12da2e3ebdSchin *                                                                      *
13da2e3ebdSchin *              Information and Software Systems Research               *
14da2e3ebdSchin *                            AT&T Research                             *
15da2e3ebdSchin *                           Florham Park NJ                            *
16da2e3ebdSchin *                                                                      *
17da2e3ebdSchin *                 Glenn Fowler <gsf@research.att.com>                  *
18da2e3ebdSchin *                  David Korn <dgk@research.att.com>                   *
19da2e3ebdSchin *                   Phong Vo <kpv@research.att.com>                    *
20da2e3ebdSchin *                                                                      *
21da2e3ebdSchin ***********************************************************************/
22da2e3ebdSchin #include	"sfhdr.h"
23da2e3ebdSchin 
24da2e3ebdSchin /*	Set some control flags or file descript for the stream
25da2e3ebdSchin **
26da2e3ebdSchin **	Written by Kiem-Phong Vo.
27da2e3ebdSchin */
28da2e3ebdSchin 
29da2e3ebdSchin #if __STD_C
sfset(Sfio_t * f,int flags,int set)307c2fbfb3SApril Chin int sfset(Sfio_t* f, int flags, int set)
31da2e3ebdSchin #else
32da2e3ebdSchin int sfset(f,flags,set)
337c2fbfb3SApril Chin Sfio_t*		f;
347c2fbfb3SApril Chin int		flags;
357c2fbfb3SApril Chin int		set;
36da2e3ebdSchin #endif
37da2e3ebdSchin {
38da2e3ebdSchin 	reg int	oflags;
397c2fbfb3SApril Chin 	SFMTXDECL(f);
40da2e3ebdSchin 
417c2fbfb3SApril Chin 	SFMTXENTER(f,0);
42da2e3ebdSchin 
43da2e3ebdSchin 	if(flags == 0 && set == 0)
44da2e3ebdSchin 		SFMTXRETURN(f, (f->flags&SF_FLAGS));
45da2e3ebdSchin 
46da2e3ebdSchin 	if((oflags = (f->mode&SF_RDWR)) != (int)f->mode && _sfmode(f,oflags,0) < 0)
47da2e3ebdSchin 		SFMTXRETURN(f, 0);
48da2e3ebdSchin 
49da2e3ebdSchin 	if(flags == 0)
50da2e3ebdSchin 		SFMTXRETURN(f, (f->flags&SF_FLAGS));
51da2e3ebdSchin 
52da2e3ebdSchin 	SFLOCK(f,0);
53da2e3ebdSchin 
54da2e3ebdSchin 	/* preserve at least one rd/wr flag */
55da2e3ebdSchin 	oflags = f->flags;
56da2e3ebdSchin 	if(!(f->bits&SF_BOTH) || (flags&SF_RDWR) == SF_RDWR )
57da2e3ebdSchin 		flags &= ~SF_RDWR;
58da2e3ebdSchin 
59da2e3ebdSchin 	/* set the flag */
60da2e3ebdSchin 	if(set)
61da2e3ebdSchin 		f->flags |=  (flags&SF_SETS);
62da2e3ebdSchin 	else	f->flags &= ~(flags&SF_SETS);
63da2e3ebdSchin 
64da2e3ebdSchin 	/* must have at least one of read/write */
65da2e3ebdSchin 	if(!(f->flags&SF_RDWR))
66da2e3ebdSchin 		f->flags |= (oflags&SF_RDWR);
67da2e3ebdSchin 
68da2e3ebdSchin 	if(f->extent < 0)
69da2e3ebdSchin 		f->flags &= ~SF_APPENDWR;
70da2e3ebdSchin 
71da2e3ebdSchin 	/* turn to appropriate mode as necessary */
72da2e3ebdSchin 	if((flags &= SF_RDWR) )
73da2e3ebdSchin 	{	if(!set)
74da2e3ebdSchin 		{	if(flags == SF_READ)
75da2e3ebdSchin 				flags = SF_WRITE;
76da2e3ebdSchin 			else	flags = SF_READ;
77da2e3ebdSchin 		}
78da2e3ebdSchin 		if((flags == SF_WRITE && !(f->mode&SF_WRITE)) ||
79da2e3ebdSchin 		   (flags == SF_READ && !(f->mode&(SF_READ|SF_SYNCED))) )
80da2e3ebdSchin 			(void)_sfmode(f,flags,1);
81da2e3ebdSchin 	}
82da2e3ebdSchin 
83da2e3ebdSchin 	/* if not shared or unseekable, public means nothing */
84da2e3ebdSchin 	if(!(f->flags&SF_SHARE) || f->extent < 0)
85da2e3ebdSchin 		f->flags &= ~SF_PUBLIC;
86da2e3ebdSchin 
87da2e3ebdSchin 	SFOPEN(f,0);
88da2e3ebdSchin 	SFMTXRETURN(f, (oflags&SF_FLAGS));
89da2e3ebdSchin }
90