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. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)lookup.c 8.1 (Berkeley) 6/9/93
  30  * $FreeBSD: src/usr.bin/rdist/lookup.c,v 1.6 1999/08/28 01:05:07 peter Exp $
  31  * $DragonFly: src/usr.bin/rdist/lookup.c,v 1.4 2008/10/16 01:52:33 swildner Exp $
  32  */
  33
  34 #include "defs.h"
  35
  36 /* symbol types */
  37 #define VAR     1
  38 #define CONST   2
  39
  40 struct syment {
  41         int     s_type;
  42         char    *s_name;
  43         struct  namelist *s_value;
  44         struct  syment *s_next;
  45 };
  46
  47 static struct syment *hashtab[HASHSIZE];
  48
  49 /*
  50  * Define a variable from a command line argument.
  51  */
  52 void
  53 define(char *name)
  54 {
  55         char *cp, *s;
  56         struct namelist *nl;
  57         struct namelist *value;
  58
  59         value = NULL;
  60
  61         if (debug)
  62                 printf("define(%s)\n", name);
  63
  64         cp = index(name, '=');
  65         if (cp == NULL)
  66                 value = NULL;
  67         else if (cp[1] == '\0') {
  68                 *cp = '\0';
  69                 value = NULL;
  70         } else if (cp[1] != '(') {
  71                 *cp++ = '\0';
  72                 value = makenl(cp);
  73         } else {
  74                 nl = NULL;
  75                 *cp++ = '\0';
  76                 do
  77                         cp++;
  78                 while (*cp == ' ' || *cp == '\t');
  79                 for (s = cp; ; s++) {
  80                         switch (*s) {
  81                         case ')':
  82                                 *s = '\0';
  83                         case '\0':
  84                                 break;
  85                         case ' ':
  86                         case '\t':
  87                                 *s++ = '\0';
  88                                 while (*s == ' ' || *s == '\t')
  89                                         s++;
  90                                 if (*s == ')')
  91                                         *s = '\0';
  92                                 break;
  93                         default:
  94                                 continue;
  95                         }
  96                         if (nl == NULL)
  97                                 value = nl = makenl(cp);
  98                         else {
  99                                 nl->n_next = makenl(cp);
 100                                 nl = nl->n_next;
 101                         }
 102                         if (*s == '\0')
 103                                 break;
 104                         cp = s;
 105                 }
 106         }
 107         lookup(name, REPLACE, value);
 108 }
 109
 110 /*
 111  * Lookup name in the table and return a pointer to it.
 112  * LOOKUP - just do lookup, return NULL if not found.
 113  * INSERT - insert name with value, error if already defined.
 114  * REPLACE - insert or replace name with value.
 115  */
 116 struct namelist *
 117 lookup(char *name, int action, struct namelist *value)
 118 {
 119         unsigned n;
 120         char *cp;
 121         struct syment *s;
 122         char buf[BUFSIZ];
 123
 124         if (debug)
 125                 printf("lookup(%s, %d, %p)\n", name, action, value);
 126
 127         n = 0;
 128         for (cp = name; *cp; )
 129                 n += *cp++;
 130         n %= HASHSIZE;
 131
 132         for (s = hashtab[n]; s != NULL; s = s->s_next) {
 133                 if (strcmp(name, s->s_name))
 134                         continue;
 135                 if (action != LOOKUP) {
 136                         if (action != INSERT || s->s_type != CONST) {
 137                                 snprintf(buf, sizeof(buf),"%s redefined", name);
 138                                 yyerror(buf);
 139                         }
 140                 }
 141                 return(s->s_value);
 142         }
 143
 144         if (action == LOOKUP) {
 145                 snprintf(buf, sizeof(buf), "%s undefined", name);
 146                 yyerror(buf);
 147                 return(NULL);
 148         }
 149
 150         s = ALLOC(syment);
 151         if (s == NULL)
 152                 fatal("ran out of memory\n");
 153         s->s_next = hashtab[n];
 154         hashtab[n] = s;
 155         s->s_type = action == INSERT ? VAR : CONST;
 156         s->s_name = name;
 157         s->s_value = value;
 158         return(value);
 159 }