usr/src/lib/libast/common/misc/reclen.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 #pragma prototyped
  23
  24 /*
  25  * return the length of the current record at b, size n, according to f
  26  * -1 returned on error
  27  *  0 returned if more data is required
  28  */
  29
  30 #include <recfmt.h>
  31 #include <ctype.h>
  32
  33 ssize_t
  34 reclen(Recfmt_t f, const void* b, size_t n)
  35 {
  36         register unsigned char* s = (unsigned char*)b;
  37         register unsigned char* e;
  38         size_t                  h;
  39         size_t                  z;
  40
  41         switch (RECTYPE(f))
  42         {
  43         case REC_delimited:
  44                 if (e = (unsigned char*)memchr(s, REC_D_DELIMITER(f), n))
  45                         return e - s + 1;
  46                 return 0;
  47         case REC_fixed:
  48                 return REC_F_SIZE(f);
  49         case REC_variable:
  50                 h = REC_V_HEADER(f);
  51                 if (n < h)
  52                         return 0;
  53                 z = 0;
  54                 s += REC_V_OFFSET(f);
  55                 e = s + REC_V_LENGTH(f);
  56                 if (REC_V_LITTLE(f))
  57                         while (e > s)
  58                                 z = (z<<8)|*--e;
  59                 else
  60                         while (s < e)
  61                                 z = (z<<8)|*s++;
  62                 if (!REC_V_INCLUSIVE(f))
  63                         z += h;
  64                 else if (z < h)
  65                         z = h;
  66                 return z;
  67         case REC_method:
  68                 return -1;
  69         }
  70         return -1;
  71 }