crypto/dist/heimdal/appl/telnet/libtelnet/genget.c

   1 /*-
   2  * Copyright (c) 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <config.h>
  35 #include "misc-proto.h"
  36
  37 __RCSID("$Heimdal: genget.c 10646 2001-09-03 05:54:18Z assar $"
  38         "$NetBSD$");
  39
  40 #include <ctype.h>
  41
  42 #define LOWER(x) (isupper(x) ? tolower(x) : (x))
  43 /*
  44  * The prefix function returns 0 if *s1 is not a prefix
  45  * of *s2.  If *s1 exactly matches *s2, the negative of
  46  * the length is returned.  If *s1 is a prefix of *s2,
  47  * the length of *s1 is returned.
  48  */
  49
  50 int
  51 isprefix(char *s1, char *s2)
  52 {
  53     char *os1;
  54     char c1, c2;
  55
  56     if (*s1 == '\0')
  57         return(-1);
  58     os1 = s1;
  59     c1 = *s1;
  60     c2 = *s2;
  61     while (tolower((unsigned char)c1) == tolower((unsigned char)c2)) {
  62         if (c1 == '\0')
  63             break;
  64         c1 = *++s1;
  65         c2 = *++s2;
  66     }
  67     return(*s1 ? 0 : (*s2 ? (s1 - os1) : (os1 - s1)));
  68 }
  69
  70 static char *ambiguous;         /* special return value for command routines */
  71
  72 char **
  73 genget(char *name, char **table, int stlen)
  74      /* name to match */
  75      /* name entry in table */
  76
  77 {
  78     char **c, **found;
  79     int n;
  80
  81     if (name == 0)
  82         return 0;
  83
  84     found = 0;
  85     for (c = table; *c != 0; c = (char **)((char *)c + stlen)) {
  86         if ((n = isprefix(name, *c)) == 0)
  87             continue;
  88         if (n < 0)              /* exact match */
  89             return(c);
  90         if (found)
  91             return(&ambiguous);
  92         found = c;
  93     }
  94     return(found);
  95 }
  96
  97 /*
  98  * Function call version of Ambiguous()
  99  */
 100 int
 101 Ambiguous(void *s)
 102 {
 103     return((char **)s == &ambiguous);
 104 }