lib/libtelnet/genget.c

   1 /*      $NetBSD: genget.c,v 1.10 2004/10/27 19:59:24 dsl 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 1.10 2004/10/27 19:59:24 dsl 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(s1, s2)
  54         register char *s1, *s2;
  55 {
  56         char *os1;
  57         register char c1, c2;
  58
  59         if (*s1 == '\0')
  60                 return(-1);
  61         os1 = s1;
  62         c1 = *s1;
  63         c2 = *s2;
  64         while (LOWER(c1) == LOWER(c2)) {
  65                 if (c1 == '\0')
  66                         break;
  67                 c1 = *++s1;
  68                 c2 = *++s2;
  69         }
  70         return(*s1 ? 0 : (*s2 ? (s1 - os1) : (os1 - s1)));
  71 }
  72
  73 static char *ambiguous;         /* special return value for command routines */
  74
  75         char **
  76 genget(name, table, stlen)
  77         char    *name;          /* name to match */
  78         char    **table;        /* name entry in table */
  79         int     stlen;
  80 {
  81         register char **c, **found;
  82         register int n;
  83
  84         if (name == 0)
  85             return 0;
  86
  87         found = 0;
  88         for (c = table; *c != 0; c = (char **)((char *)c + stlen)) {
  89                 if ((n = isprefix(name, *c)) == 0)
  90                         continue;
  91                 if (n < 0)              /* exact match */
  92                         return(c);
  93                 if (found)
  94                         return(&ambiguous);
  95                 found = c;
  96         }
  97         return(found);
  98 }
  99
 100 /*
 101  * Function call version of Ambiguous()
 102  */
 103         int
 104 Ambiguous(s)
 105         void *s;
 106 {
 107         return(s == &ambiguous);
 108 }