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uniq.c revision 1.6 
      1 /*	$NetBSD: uniq.c,v 1.6 2014/06/21 17:48:07 christos 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 __RCSID("$NetBSD: uniq.c,v 1.6 2014/06/21 17:48:07 christos Exp $");
     33 
     34 #include <stdio.h>
     35 #include <string.h>
     36 #include <stdlib.h>
     37 #include <db.h>
     38 #include <err.h>
     39 #include <util.h>
     40 #include <ctype.h>
     41 #include <fcntl.h>
     42 
     43 #include "extern.h"
     44 
     45 static const HASHINFO hinfo = {
     46 	.bsize = 256,
     47 	.ffactor = 4,
     48 	.nelem = 32768,
     49 	.cachesize = 1024,
     50 	.hash = NULL,
     51 	.lorder = 0
     52 };
     53 
     54 static int comp(const char *, char **, size_t *);
     55 
     56 /*
     57  * Preserve only unique content lines in a file. Input lines that have
     58  * content [alphanumeric characters before a comment] are white-space
     59  * normalized and have their comments removed. Then they are placed
     60  * in a hash table, and only the first instance of them is printed.
     61  * Comment lines without any alphanumeric content are always printed
     62  * since they are there to make the file "pretty". Comment lines with
     63  * alphanumeric content are also placed into the hash table and only
     64  * printed once.
     65  */
     66 void
     67 uniq(const char *fname)
     68 {
     69 	DB *db;
     70 	DBT key;
     71 	static const DBT data = { NULL, 0 };
     72 	FILE *fp;
     73 	char *line;
     74 	size_t len;
     75 
     76 	if ((db = dbopen(NULL, O_RDWR, 0, DB_HASH, &hinfo)) == NULL)
     77 		err(1, "Cannot create in memory database");
     78 
     79 	fp = efopen(fname, "r");
     80 	while ((line = fgetln(fp, &len)) != NULL) {
     81 		size_t complen = len;
     82 		char *compline;
     83 		if (!comp(line, &compline, &complen)) {
     84 			(void)fprintf(stdout, "%*.*s", (int)len, (int)len,
     85 			    line);
     86 			continue;
     87 		}
     88 		key.data = compline;
     89 		key.size = complen;
     90 		switch ((db->put)(db, &key, &data, R_NOOVERWRITE)) {
     91 		case 0:
     92 			(void)fprintf(stdout, "%*.*s", (int)len, (int)len,
     93 			    line);
     94 			break;
     95 		case 1:
     96 			break;
     97 		case -1:
     98 			err(1, "put");
     99 			/*NOTREACHED*/
    100 		default:
    101 			abort();
    102 			break;
    103 		}
    104 	}
    105 	(void)fflush(stdout);
    106 	exit(0);
    107 }
    108 
    109 /*
    110  * normalize whitespace in the original line and place a new string
    111  * with whitespace converted to a single space in compline. If the line
    112  * contains just comments, we preserve them. If it contains data and
    113  * comments, we kill the comments. Return 1 if the line had actual
    114  * contents, or 0 if it was just a comment without alphanumeric characters.
    115  */
    116 static int
    117 comp(const char *origline, char **compline, size_t *len)
    118 {
    119 	const unsigned char *p;
    120 	unsigned char *q;
    121 	char *cline;
    122 	size_t l = *len, complen;
    123 	int hasalnum, iscomment;
    124 
    125 	/* Eat leading space */
    126 	for (p = (const unsigned char *)origline; l && *p && isspace(*p);
    127 	    p++, l--)
    128 		continue;
    129 	cline = emalloc(l + 1);
    130 	(void)memcpy(cline, p, l);
    131 	cline[l] = '\0';
    132 	if (*cline == '\0')
    133 		return 0;
    134 
    135 	complen = 0;
    136 	hasalnum = 0;
    137 	iscomment = 0;
    138 
    139 	for (q = (unsigned char *)cline; l && *p; p++, l--) {
    140 		if (isspace(*p)) {
    141 			if (complen && isspace(q[-1]))
    142 				continue;
    143 			*q++ = ' ';
    144 			complen++;
    145 		} else {
    146 			if (!iscomment && *p == '#') {
    147 				if (hasalnum)
    148 					break;
    149 				iscomment = 1;
    150 			} else
    151 				hasalnum |= isalnum(*p);
    152 			*q++ = *p;
    153 			complen++;
    154 		}
    155 	}
    156 
    157 	/* Eat trailing space */
    158 	while (complen && isspace(q[-1])) {
    159 		--q;
    160 		--complen;
    161 	}
    162 	*q = '\0';
    163 	*compline = cline;
    164 	*len = complen;
    165 	return hasalnum;
    166 }
    167