4.3BSD - /usr/src/ucb/rdist/lookup.c

   1: /*
   2:  * Copyright (c) 1983 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  */
   6: 
   7: #ifndef lint
   8: static char sccsid[] = "@(#)lookup.c	5.1 (Berkeley) 6/6/85";
   9: #endif not lint
  10: 
  11: #include "defs.h"
  12: 
  13:     /* symbol types */
  14: #define VAR 1
  15: #define CONST   2
  16: 
  17: struct syment {
  18:     int s_type;
  19:     char    *s_name;
  20:     struct  namelist *s_value;
  21:     struct  syment *s_next;
  22: };
  23: 
  24: static struct syment *hashtab[HASHSIZE];
  25: 
  26: /*
  27:  * Define a variable from a command line argument.
  28:  */
  29: define(name)
  30:     char *name;
  31: {
  32:     register char *cp, *s;
  33:     register struct namelist *nl;
  34:     struct namelist *value;
  35: 
  36:     if (debug)
  37:         printf("define(%s)\n", name);
  38: 
  39:     cp = index(name, '=');
  40:     if (cp == NULL)
  41:         value = NULL;
  42:     else if (cp[1] == '\0') {
  43:         *cp = '\0';
  44:         value = NULL;
  45:     } else if (cp[1] != '(') {
  46:         *cp++ = '\0';
  47:         value = makenl(cp);
  48:     } else {
  49:         nl = NULL;
  50:         *cp++ = '\0';
  51:         do
  52:             cp++;
  53:         while (*cp == ' ' || *cp == '\t');
  54:         for (s = cp; ; s++) {
  55:             switch (*s) {
  56:             case ')':
  57:                 *s = '\0';
  58:             case '\0':
  59:                 break;
  60:             case ' ':
  61:             case '\t':
  62:                 *s++ = '\0';
  63:                 while (*s == ' ' || *s == '\t')
  64:                     s++;
  65:                 if (*s == ')')
  66:                     *s = '\0';
  67:                 break;
  68:             default:
  69:                 continue;
  70:             }
  71:             if (nl == NULL)
  72:                 value = nl = makenl(cp);
  73:             else {
  74:                 nl->n_next = makenl(cp);
  75:                 nl = nl->n_next;
  76:             }
  77:             if (*s == '\0')
  78:                 break;
  79:             cp = s;
  80:         }
  81:     }
  82:     (void) lookup(name, REPLACE, value);
  83: }
  84: 
  85: /*
  86:  * Lookup name in the table and return a pointer to it.
  87:  * LOOKUP - just do lookup, return NULL if not found.
  88:  * INSERT - insert name with value, error if already defined.
  89:  * REPLACE - insert or replace name with value.
  90:  */
  91: 
  92: struct namelist *
  93: lookup(name, action, value)
  94:     char *name;
  95:     int action;
  96:     struct namelist *value;
  97: {
  98:     register unsigned n;
  99:     register char *cp;
 100:     register struct syment *s;
 101:     char buf[256];
 102: 
 103:     if (debug)
 104:         printf("lookup(%s, %d, %x)\n", name, action, value);
 105: 
 106:     n = 0;
 107:     for (cp = name; *cp; )
 108:         n += *cp++;
 109:     n %= HASHSIZE;
 110: 
 111:     for (s = hashtab[n]; s != NULL; s = s->s_next) {
 112:         if (strcmp(name, s->s_name))
 113:             continue;
 114:         if (action != LOOKUP) {
 115:             if (action != INSERT || s->s_type != CONST) {
 116:                 sprintf(buf, "%s redefined", name);
 117:                 yyerror(buf);
 118:             }
 119:         }
 120:         return(s->s_value);
 121:     }
 122: 
 123:     if (action == LOOKUP) {
 124:         yyerror(sprintf(buf, "%s undefined", name));
 125:         return(NULL);
 126:     }
 127: 
 128:     s = ALLOC(syment);
 129:     if (s == NULL)
 130:         fatal("ran out of memory\n");
 131:     s->s_next = hashtab[n];
 132:     hashtab[n] = s;
 133:     s->s_type = action == INSERT ? VAR : CONST;
 134:     s->s_name = name;
 135:     s->s_value = value;
 136:     return(value);
 137: }

Defined functions

Defined variables

Defined struct's

Defined macros