usr/src/lib/libast/common/disc/sfdctee.c

   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        "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 }