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
sfset(Sfio_t * f,int flags,int set)30 int sfset(Sfio_t* f, int flags, int set)
31 #else
32 int sfset(f,flags,set)
33 Sfio_t* f;
34 int flags;
35 int 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