usr.bin/rdist/lookup.c

   1 /*
   2  * Copyright (c) 1983, 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  * @(#)lookup.c 8.1 (Berkeley) 6/9/93
  34  * $FreeBSD: src/usr.bin/rdist/lookup.c,v 1.6 1999/08/28 01:05:07 peter Exp $
  35  * $DragonFly: src/usr.bin/rdist/lookup.c,v 1.4 2008/10/16 01:52:33 swildner Exp $
  36  */
  37
  38 #include "defs.h"
  39
  40 /* symbol types */
  41 #define VAR     1
  42 #define CONST   2
  43
  44 struct syment {
  45         int     s_type;
  46         char    *s_name;
  47         struct  namelist *s_value;
  48         struct  syment *s_next;
  49 };
  50
  51 static struct syment *hashtab[HASHSIZE];
  52
  53 /*
  54  * Define a variable from a command line argument.
  55  */
  56 void
  57 define(char *name)
  58 {
  59         char *cp, *s;
  60         struct namelist *nl;
  61         struct namelist *value;
  62
  63         value = NULL;
  64
  65         if (debug)
  66                 printf("define(%s)\n", name);
  67
  68         cp = index(name, '=');
  69         if (cp == NULL)
  70                 value = NULL;
  71         else if (cp[1] == '\0') {
  72                 *cp = '\0';
  73                 value = NULL;
  74         } else if (cp[1] != '(') {
  75                 *cp++ = '\0';
  76                 value = makenl(cp);
  77         } else {
  78                 nl = NULL;
  79                 *cp++ = '\0';
  80                 do
  81                         cp++;
  82                 while (*cp == ' ' || *cp == '\t');
  83                 for (s = cp; ; s++) {
  84                         switch (*s) {
  85                         case ')':
  86                                 *s = '\0';
  87                         case '\0':
  88                                 break;
  89                         case ' ':
  90                         case '\t':
  91                                 *s++ = '\0';
  92                                 while (*s == ' ' || *s == '\t')
  93                                         s++;
  94                                 if (*s == ')')
  95                                         *s = '\0';
  96                                 break;
  97                         default:
  98                                 continue;
  99                         }
 100                         if (nl == NULL)
 101                                 value = nl = makenl(cp);
 102                         else {
 103                                 nl->n_next = makenl(cp);
 104                                 nl = nl->n_next;
 105                         }
 106                         if (*s == '\0')
 107                                 break;
 108                         cp = s;
 109                 }
 110         }
 111         lookup(name, REPLACE, value);
 112 }
 113
 114 /*
 115  * Lookup name in the table and return a pointer to it.
 116  * LOOKUP - just do lookup, return NULL if not found.
 117  * INSERT - insert name with value, error if already defined.
 118  * REPLACE - insert or replace name with value.
 119  */
 120 struct namelist *
 121 lookup(char *name, int action, struct namelist *value)
 122 {
 123         unsigned n;
 124         char *cp;
 125         struct syment *s;
 126         char buf[BUFSIZ];
 127
 128         if (debug)
 129                 printf("lookup(%s, %d, %p)\n", name, action, value);
 130
 131         n = 0;
 132         for (cp = name; *cp; )
 133                 n += *cp++;
 134         n %= HASHSIZE;
 135
 136         for (s = hashtab[n]; s != NULL; s = s->s_next) {
 137                 if (strcmp(name, s->s_name))
 138                         continue;
 139                 if (action != LOOKUP) {
 140                         if (action != INSERT || s->s_type != CONST) {
 141                                 snprintf(buf, sizeof(buf),"%s redefined", name);
 142                                 yyerror(buf);
 143                         }
 144                 }
 145                 return(s->s_value);
 146         }
 147
 148         if (action == LOOKUP) {
 149                 snprintf(buf, sizeof(buf), "%s undefined", name);
 150                 yyerror(buf);
 151                 return(NULL);
 152         }
 153
 154         s = ALLOC(syment);
 155         if (s == NULL)
 156                 fatal("ran out of memory\n");
 157         s->s_next = hashtab[n];
 158         hashtab[n] = s;
 159         s->s_type = action == INSERT ? VAR : CONST;
 160         s->s_name = name;
 161         s->s_value = value;
 162         return(value);
 163 }