lib/libtelnet/genget.c

   1 /*      $NetBSD: genget.c,v 1.13 2012/03/21 05:33:27 matt Exp $ */
   2
   3 /*-
   4  * Copyright (c) 1991, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 #if 0
  35 static char sccsid[] = "@(#)genget.c    8.2 (Berkeley) 5/30/95";
  36 #else
  37 __RCSID("$NetBSD: genget.c,v 1.13 2012/03/21 05:33:27 matt Exp $");
  38 #endif
  39 #endif /* not lint */
  40
  41
  42 #include <ctype.h>
  43 #include "misc.h"
  44
  45 #define LOWER(x) (isupper((unsigned char)x) ? tolower((unsigned char)x) : (x))
  46 /*
  47  * The prefix function returns 0 if *s1 is not a prefix
  48  * of *s2.  If *s1 exactly matches *s2, the negative of
  49  * the length is returned.  If *s1 is a prefix of *s2,
  50  * the length of *s1 is returned.
  51  */
  52 int
  53 isprefix(char *s1, const char *s2)
  54 {
  55         char *os1;
  56         char c1, c2;
  57
  58         if (*s1 == '\0')
  59                 return(-1);
  60         os1 = s1;
  61         c1 = *s1;
  62         c2 = *s2;
  63         while (LOWER(c1) == LOWER(c2)) {
  64                 if (c1 == '\0')
  65                         break;
  66                 c1 = *++s1;
  67                 c2 = *++s2;
  68         }
  69         return(*s1 ? 0 : (*s2 ? (s1 - os1) : (os1 - s1)));
  70 }
  71
  72 static char *ambiguous;         /* special return value for command routines */
  73
  74 char **
  75 genget( char    *name,          /* name to match */
  76         char    **table,        /* name entry in table */
  77         int     stlen)
  78 {
  79         register char **c, **found;
  80         register int n;
  81
  82         if (name == 0)
  83             return 0;
  84
  85         found = 0;
  86         for (c = table; *c != 0; c = (char **)((char *)c + stlen)) {
  87                 if ((n = isprefix(name, *c)) == 0)
  88                         continue;
  89                 if (n < 0)              /* exact match */
  90                         return(c);
  91                 if (found)
  92                         return(&ambiguous);
  93                 found = c;
  94         }
  95         return(found);
  96 }
  97
  98 /*
  99  * Function call version of Ambiguous()
 100  */
 101 int
 102 Ambiguous(void *s)
 103 {
 104         return(s == &ambiguous);
 105 }