usr.sbin/sup/source/skipto.c

   1 /*      $NetBSD: skipto.c,v 1.5 2002/07/10 20:19:43 wiz Exp $   */
   2
   3 /*
   4  * Copyright (c) 1991 Carnegie Mellon University
   5  * All Rights Reserved.
   6  *
   7  * Permission to use, copy, modify and distribute this software and its
   8  * documentation is hereby granted, provided that both the copyright
   9  * notice and this permission notice appear in all copies of the
  10  * software, derivative works or modified versions, and any portions
  11  * thereof, and that both notices appear in supporting documentation.
  12  *
  13  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  14  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  15  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  16  *
  17  * Carnegie Mellon requests users of this software to return to
  18  *
  19  *  Software Distribution Coordinator   or   Software.Distribution@CS.CMU.EDU
  20  *  School of Computer Science
  21  *  Carnegie Mellon University
  22  *  Pittsburgh PA 15213-3890
  23  *
  24  * any improvements or extensions that they make and grant Carnegie the rights
  25  * to redistribute these changes.
  26  */
  27 /************************************************************************
  28  *  skipover and skipto -- skip over characters in string
  29  *
  30  *  Usage:      p = skipto (string,charset);
  31  *              p = skipover (string,charset);
  32  *
  33  *  char *p,*charset,*string;
  34  *
  35  *  Skipto returns a pointer to the first character in string which
  36  *  is in the string charset; it "skips until" a character in charset.
  37  *  Skipover returns a pointer to the first character in string which
  38  *  is not in the string charset; it "skips over" characters in charset.
  39  ************************************************************************
  40  * HISTORY
  41  * 26-Jun-81  David Smith (drs) at Carnegie-Mellon University
  42  *      Skipover, skipto rewritten to avoid inner loop at expense of space.
  43  *
  44  * 20-Nov-79  Steven Shafer (sas) at Carnegie-Mellon University
  45  *      Skipover, skipto adapted for VAX from skip() and skipx() on the PDP-11
  46  *      (from Ken Greer).  The names are more mnemonic.
  47  *
  48  *      Sindex adapted for VAX from indexs() on the PDP-11 (thanx to Ralph
  49  *      Guggenheim).  The name has changed to be more like the index()
  50  *      and rindex() functions from Bell Labs; the return value (pointer
  51  *      rather than integer) has changed partly for the same reason,
  52  *      and partly due to popular usage of this function.
  53  */
  54
  55 #include "supcdefs.h"
  56 #include "supextern.h"
  57
  58 static char tab[256] = { 0 };
  59
  60 char *
  61 skipto(const char *string, const char *charset)
  62 {
  63         const char *setp, *strp;
  64
  65         tab[0] = 1;             /* Stop on a null, too. */
  66         for (setp = charset; *setp; setp++)
  67                 tab[(unsigned char) *setp] = 1;
  68         for (strp = string; tab[(unsigned char) *strp] == 0; strp++)
  69                 continue;
  70         for (setp = charset; *setp; setp++)
  71                 tab[(unsigned char) *setp] = 0;
  72         return __UNCONST(strp);
  73 }
  74
  75 char *
  76 skipover(const char *string, const char *charset)
  77 {
  78         const char *setp, *strp;
  79
  80         tab[0] = 0;             /* Do not skip over nulls. */
  81         for (setp = charset; *setp; setp++)
  82                 tab[(unsigned char) *setp] = 1;
  83         for (strp = string; tab[(unsigned char) *strp]; strp++)
  84                 continue;
  85         for (setp = charset; *setp; setp++)
  86                 tab[(unsigned char) *setp] = 0;
  87         return __UNCONST(strp);
  88 }