table.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 1994, by Sun Microsystems, Inc.
* All rights reserved.
*/
#ident "%Z%%M% %I% %E% SMI" /* SMI4.1 1.4 */
#include <ctype.h>
#include "util.h"
#include "table.h"
/*
* Hash table manager. Store/lookup strings, keyed by string
*/
/*
* Generate the key into the table using the first two letters
* of "str". The table is alphabetized, with no distinction between
* upper and lower case. Non-letters are given least significance.
*/
int
tablekey(str)
register char *str;
{
#define TOLOWER(c) (islower(c) ? c : \
(isupper(c) ? tolower(c) : ('a'+NUMLETTERS-1)))
register int c1, c2;
c1 = *str++;
c2 = *str;
if (c1 == EOS) {
c2 = EOS; /* just in case */
}
c1 = TOLOWER(c1) - 'a';
c2 = TOLOWER(c2) - 'a';
return (c1*NUMLETTERS + c2);
}
void
store(table, key, datum)
stringtable table;
char *key;
char *datum;
{
int index;
tablelist cur, new;
index = tablekey(key);
cur = table[index];
new = MALLOC(tablenode);
new->key = key;
new->datum = datum;
new->next = cur;
table[index] = new;
}
char *
lookup(table, key)
stringtable table;
char *key;
{
tablelist cur;
cur = table[tablekey(key)];
while (cur && strcmp(cur->key, key)) {
cur = cur->next;
}
if (cur) {
return (cur->datum);
} else {
return (NULL);
}
}