usr/src/lib/libast/common/disc/sfdcprefix.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 /*
  25  * a discipline that prepends a prefix string to each output line
  26  *
  27  * Glenn Fowler
  28  * AT&T Research
  29  *
  30  * @(#)$Id: sfdcprefix (AT&T Research) 1998-06-25 $
  31  */
  32
  33 typedef struct
  34 {
  35         Sfdisc_t        disc;           /* sfio discipline              */
  36         size_t          length;         /* prefix length                */
  37         size_t          empty;          /* empty line prefix length     */
  38         int             skip;           /* this line already prefixed   */
  39         char            prefix[1];      /* prefix string                */
  40 } Prefix_t;
  41
  42 /*
  43  * prefix write
  44  */
  45
  46 #if __STD_C
  47 static ssize_t pfxwrite(Sfio_t* f, const Void_t* buf, register size_t n, Sfdisc_t* dp)
  48 #else
  49 static ssize_t pfxwrite(f, buf, n, dp)
  50 Sfio_t*         f;
  51 Void_t*         buf;
  52 register size_t n;
  53 Sfdisc_t*       dp;
  54 #endif
  55 {
  56         register Prefix_t*      pfx = (Prefix_t*)dp;
  57         register char*          b;
  58         register char*          s;
  59         register char*          e;
  60         register char*          t;
  61         register ssize_t        w;
  62         int                     skip;
  63
  64         skip = 0;
  65         w = 0;
  66         b = (char*)buf;
  67         s = b;
  68         e = s + n;
  69         do
  70         {
  71                 if (!(t = memchr(s, '\n', e - s)))
  72                 {
  73                         skip = 1;
  74                         t = e - 1;
  75                 }
  76                 n = t - s + 1;
  77                 if (pfx->skip)
  78                         pfx->skip = 0;
  79                 else
  80                         sfwr(f, pfx->prefix, n > 1 ? pfx->length : pfx->empty, dp);
  81                 w += sfwr(f, s, n, dp);
  82                 if ((s = t + 1) >= e)
  83                         return w;
  84         } while ((s = t + 1) < e);
  85         pfx->skip = skip;
  86         return w;
  87
  88 }
  89
  90 /*
  91  * remove the discipline on close
  92  */
  93
  94 #if __STD_C
  95 static int pfxexcept(Sfio_t* f, int type, Void_t* data, Sfdisc_t* dp)
  96 #else
  97 static int pfxexcept(f, type, data, dp)
  98 Sfio_t*         f;
  99 int             type;
 100 Void_t*         data;
 101 Sfdisc_t*       dp;
 102 #endif
 103 {
 104         if (type == SF_FINAL || type == SF_DPOP)
 105                 free(dp);
 106         return 0;
 107 }
 108
 109 /*
 110  * push the prefix discipline on f
 111  */
 112
 113 #if __STD_C
 114 int sfdcprefix(Sfio_t* f, const char* prefix)
 115 #else
 116 int sfdcprefix(f, prefix)
 117 Sfio_t*         f;
 118 char*           prefix;
 119 #endif
 120 {
 121         register Prefix_t*      pfx;
 122         register char*          s;
 123         size_t                  n;
 124
 125         /*
 126          * this is a writeonly discipline
 127          */
 128
 129         if (!prefix || !(n = strlen(prefix)) || !(sfset(f, 0, 0) & SF_WRITE))
 130                 return -1;
 131         if (!(pfx = (Prefix_t*)malloc(sizeof(Prefix_t) + n)))
 132                 return -1;
 133         memset(pfx, 0, sizeof(*pfx));
 134
 135         pfx->disc.writef = pfxwrite;
 136         pfx->disc.exceptf = pfxexcept;
 137         pfx->length = n;
 138         memcpy(pfx->prefix, prefix, n);
 139         s = (char*)prefix + n;
 140         while (--s > (char*)prefix && (*s == ' ' || *s == '\t'));
 141         n = s - (char*)prefix;
 142         if (*s != ' ' || *s != '\t')
 143                 n++;
 144         pfx->empty = n;
 145
 146         if (sfdisc(f, &pfx->disc) != &pfx->disc)
 147         {
 148                 free(pfx);
 149                 return -1;
 150         }
 151
 152         return 0;
 153 }