xref: /titanic_41/usr/src/lib/libast/common/disc/sfdctee.c (revision 2a9459bdd821c1cf59590a7a9069ac9c591e8a6b)
1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *           Copyright (c) 1985-2007 AT&T Knowledge Ventures            *
5 *                      and is licensed under the                       *
6 *                  Common Public License, Version 1.0                  *
7 *                      by AT&T Knowledge Ventures                      *
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	"sfdchdr.h"
23 
24 /*	A discipline to tee the output to a stream to another stream.
25 **	This is similar to what the "tee" program does. As implemented
26 **	this discipline only works with file streams.
27 **
28 **	Written by Kiem-Phong Vo, kpv@research.att.com, 03/18/1998.
29 */
30 
31 /* the discipline structure for tee-ing */
32 typedef struct _tee_s
33 {	Sfdisc_t	disc;	/* the sfio discipline structure */
34 	Sfio_t*		tee;	/* the stream to tee to */
35 	int		status;	/* if tee stream is still ok */
36 } Tee_t;
37 
38 /*	write to the teed stream.  */
39 #if __STD_C
40 static ssize_t teewrite(Sfio_t* f, const Void_t* buf, size_t size, Sfdisc_t* disc)
41 #else
42 static ssize_t teewrite(f,buf,size,disc)
43 Sfio_t* 	f;	/* the stream being written to */
44 Void_t*		buf;	/* the buffer of data being output */
45 size_t		size;	/* the data size */
46 Sfdisc_t*	disc;	/* the tee discipline */
47 #endif
48 {
49 	reg Tee_t*	te = (Tee_t*)disc;
50 
51 	/* tee data if still ok */
52 	if(te->status == 0 && sfwrite(te->tee,buf,size) != (ssize_t)size)
53 		te->status = -1;
54 
55 	/* do the actual write */
56 	return sfwr(f,buf,size,disc);
57 }
58 
59 /* on close, remove the discipline */
60 #if __STD_C
61 static int teeexcept(Sfio_t* f, int type, Void_t* data, Sfdisc_t* disc)
62 #else
63 static int teeexcept(f,type,data,disc)
64 Sfio_t*		f;
65 int		type;
66 Void_t*		data;
67 Sfdisc_t*	disc;
68 #endif
69 {
70 	if(type == SF_FINAL || type == SF_DPOP)
71 		free(disc);
72 
73 	return 0;
74 }
75 
76 #if __STD_C
77 int sfdctee(Sfio_t* f, Sfio_t* tee)
78 #else
79 int sfdctee(f, tee)
80 Sfio_t*	f;	/* stream to tee from	*/
81 Sfio_t*	tee;	/* stream to tee to	*/
82 #endif
83 {
84 	reg Tee_t*	te;
85 
86 	if(!(te = (Tee_t*)malloc(sizeof(Tee_t))) )
87 		return -1;
88 
89 	te->disc.readf = NIL(Sfread_f);
90 	te->disc.seekf = NIL(Sfseek_f);
91 	te->disc.writef = teewrite;
92 	te->disc.exceptf = teeexcept;
93 	te->tee = tee;
94 	te->status = 0;
95 
96 	if(sfdisc(f,(Sfdisc_t*)te) != (Sfdisc_t*)te)
97 	{	free(te);
98 		return -1;
99 	}
100 
101 	return 0;
102 }
103