uniq.c revision 267654 
1/*	$NetBSD: uniq.c,v 1.4 2008/04/28 20:24:17 martin Exp $	*/
2
3/*-
4 * Copyright (c) 2007 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Christos Zoulas.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: releng/9.3/usr.sbin/services_mkdb/uniq.c 206156 2010-04-04 08:38:14Z ume $");
33
34#include <stdio.h>
35#include <string.h>
36#include <stdlib.h>
37#include <db.h>
38#include <err.h>
39#include <libutil.h>
40#include <ctype.h>
41#include <fcntl.h>
42
43extern const HASHINFO hinfo;
44
45void uniq(const char *);
46static int comp(const char *, char **, size_t *);
47
48/*
49 * Preserve only unique content lines in a file. Input lines that have
50 * content [alphanumeric characters before a comment] are white-space
51 * normalized and have their comments removed. Then they are placed
52 * in a hash table, and only the first instance of them is printed.
53 * Comment lines without any alphanumeric content are always printed
54 * since they are there to make the file "pretty". Comment lines with
55 * alphanumeric content are also placed into the hash table and only
56 * printed once.
57 */
58void
59uniq(const char *fname)
60{
61	DB *db;
62	DBT key;
63	static const DBT data = { NULL, 0 };
64	FILE *fp;
65	char *line;
66	size_t len;
67
68	if ((db = dbopen(NULL, O_RDWR, 0, DB_HASH, &hinfo)) == NULL)
69		err(1, "Cannot create in memory database");
70
71	if ((fp = fopen(fname, "r")) == NULL)
72		err(1, "Cannot open `%s'", fname);
73	while ((line = fgetln(fp, &len)) != NULL) {
74		size_t complen = len;
75		char *compline;
76		if (!comp(line, &compline, &complen)) {
77			(void)fprintf(stdout, "%*.*s", (int)len, (int)len,
78			    line);
79			continue;
80		}
81		key.data = compline;
82		key.size = complen;
83		switch ((db->put)(db, &key, &data, R_NOOVERWRITE)) {
84		case 0:
85			(void)fprintf(stdout, "%*.*s", (int)len, (int)len,
86			    line);
87			break;
88		case 1:
89			break;
90		case -1:
91			err(1, "put");
92		default:
93			abort();
94			break;
95		}
96	}
97	(void)fflush(stdout);
98	exit(0);
99}
100
101/*
102 * normalize whitespace in the original line and place a new string
103 * with whitespace converted to a single space in compline. If the line
104 * contains just comments, we preserve them. If it contains data and
105 * comments, we kill the comments. Return 1 if the line had actual
106 * contents, or 0 if it was just a comment without alphanumeric characters.
107 */
108static int
109comp(const char *origline, char **compline, size_t *len)
110{
111	const unsigned char *p;
112	unsigned char *q;
113	char *cline;
114	size_t l = *len, complen;
115	int hasalnum, iscomment;
116
117	/* Eat leading space */
118	for (p = (const unsigned char *)origline; l && *p && isspace(*p);
119	    p++, l--)
120		continue;
121	if ((cline = malloc(l + 1)) == NULL)
122		err(1, "Cannot allocate %zu bytes", l + 1);
123	(void)memcpy(cline, p, l);
124	cline[l] = '\0';
125	if (*cline == '\0')
126		return 0;
127
128	complen = 0;
129	hasalnum = 0;
130	iscomment = 0;
131
132	for (q = (unsigned char *)cline; l && *p; p++, l--) {
133		if (isspace(*p)) {
134			if (complen && isspace(q[-1]))
135				continue;
136			*q++ = ' ';
137			complen++;
138		} else {
139			if (!iscomment && *p == '#') {
140				if (hasalnum)
141					break;
142				iscomment = 1;
143			} else
144				hasalnum |= isalnum(*p);
145			*q++ = *p;
146			complen++;
147		}
148	}
149
150	/* Eat trailing space */
151	while (complen && isspace(q[-1])) {
152		--q;
153		--complen;
154	}
155	*q = '\0';
156	*compline = cline;
157	*len = complen;
158	return hasalnum;
159}
160