1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1989, 1993, 1994
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Case Larsen.
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 * 3. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#ifndef lint
36static const char copyright[] =
37"@(#) Copyright (c) 1989, 1993, 1994\n\
38	The Regents of the University of California.  All rights reserved.\n";
39#endif
40
41#if 0
42#ifndef lint
43static char sccsid[] = "From: @(#)comm.c	8.4 (Berkeley) 5/4/95";
44#endif
45#endif
46
47#include <sys/cdefs.h>
48__FBSDID("$FreeBSD$");
49
50#include <err.h>
51#include <limits.h>
52#include <locale.h>
53#include <stdint.h>
54#include <stdio.h>
55#include <stdlib.h>
56#include <string.h>
57#include <unistd.h>
58#include <wchar.h>
59#include <wctype.h>
60
61static int iflag;
62static const char *tabs[] = { "", "\t", "\t\t" };
63
64static FILE	*file(const char *);
65static wchar_t	*convert(const char *);
66static void	show(FILE *, const char *, const char *, char **, size_t *);
67static void	usage(void);
68
69int
70main(int argc, char *argv[])
71{
72	int comp, read1, read2;
73	int ch, flag1, flag2, flag3;
74	FILE *fp1, *fp2;
75	const char *col1, *col2, *col3;
76	size_t line1len, line2len;
77	char *line1, *line2;
78	ssize_t n1, n2;
79	wchar_t *tline1, *tline2;
80	const char **p;
81
82	(void) setlocale(LC_ALL, "");
83
84	flag1 = flag2 = flag3 = 1;
85
86	while ((ch = getopt(argc, argv, "123i")) != -1)
87		switch(ch) {
88		case '1':
89			flag1 = 0;
90			break;
91		case '2':
92			flag2 = 0;
93			break;
94		case '3':
95			flag3 = 0;
96			break;
97		case 'i':
98			iflag = 1;
99			break;
100		case '?':
101		default:
102			usage();
103		}
104	argc -= optind;
105	argv += optind;
106
107	if (argc != 2)
108		usage();
109
110	fp1 = file(argv[0]);
111	fp2 = file(argv[1]);
112
113	/* for each column printed, add another tab offset */
114	p = tabs;
115	col1 = col2 = col3 = NULL;
116	if (flag1)
117		col1 = *p++;
118	if (flag2)
119		col2 = *p++;
120	if (flag3)
121		col3 = *p;
122
123	line1len = line2len = 0;
124	line1 = line2 = NULL;
125	n1 = n2 = -1;
126
127	for (read1 = read2 = 1;;) {
128		/* read next line, check for EOF */
129		if (read1) {
130			n1 = getline(&line1, &line1len, fp1);
131			if (n1 < 0 && ferror(fp1))
132				err(1, "%s", argv[0]);
133			if (n1 > 0 && line1[n1 - 1] == '\n')
134				line1[n1 - 1] = '\0';
135
136		}
137		if (read2) {
138			n2 = getline(&line2, &line2len, fp2);
139			if (n2 < 0 && ferror(fp2))
140				err(1, "%s", argv[1]);
141			if (n2 > 0 && line2[n2 - 1] == '\n')
142				line2[n2 - 1] = '\0';
143		}
144
145		/* if one file done, display the rest of the other file */
146		if (n1 < 0) {
147			if (n2 >= 0 && col2 != NULL)
148				show(fp2, argv[1], col2, &line2, &line2len);
149			break;
150		}
151		if (n2 < 0) {
152			if (n1 >= 0 && col1 != NULL)
153				show(fp1, argv[0], col1, &line1, &line1len);
154			break;
155		}
156
157		tline2 = NULL;
158		if ((tline1 = convert(line1)) != NULL)
159			tline2 = convert(line2);
160		if (tline1 == NULL || tline2 == NULL)
161			comp = strcmp(line1, line2);
162		else
163			comp = wcscoll(tline1, tline2);
164		if (tline1 != NULL)
165			free(tline1);
166		if (tline2 != NULL)
167			free(tline2);
168
169		/* lines are the same */
170		if (!comp) {
171			read1 = read2 = 1;
172			if (col3 != NULL)
173				(void)printf("%s%s\n", col3, line1);
174			continue;
175		}
176
177		/* lines are different */
178		if (comp < 0) {
179			read1 = 1;
180			read2 = 0;
181			if (col1 != NULL)
182				(void)printf("%s%s\n", col1, line1);
183		} else {
184			read1 = 0;
185			read2 = 1;
186			if (col2 != NULL)
187				(void)printf("%s%s\n", col2, line2);
188		}
189	}
190	exit(0);
191}
192
193static wchar_t *
194convert(const char *str)
195{
196	size_t n;
197	wchar_t *buf, *p;
198
199	if ((n = mbstowcs(NULL, str, 0)) == (size_t)-1)
200		return (NULL);
201	if (SIZE_MAX / sizeof(*buf) < n + 1)
202		errx(1, "conversion buffer length overflow");
203	if ((buf = malloc((n + 1) * sizeof(*buf))) == NULL)
204		err(1, "malloc");
205	if (mbstowcs(buf, str, n + 1) != n)
206		errx(1, "internal mbstowcs() error");
207
208	if (iflag) {
209		for (p = buf; *p != L'\0'; p++)
210			*p = towlower(*p);
211	}
212
213	return (buf);
214}
215
216static void
217show(FILE *fp, const char *fn, const char *offset, char **bufp, size_t *buflenp)
218{
219	ssize_t n;
220
221	do {
222		(void)printf("%s%s\n", offset, *bufp);
223		if ((n = getline(bufp, buflenp, fp)) < 0)
224			break;
225		if (n > 0 && (*bufp)[n - 1] == '\n')
226			(*bufp)[n - 1] = '\0';
227	} while (1);
228	if (ferror(fp))
229		err(1, "%s", fn);
230}
231
232static FILE *
233file(const char *name)
234{
235	FILE *fp;
236
237	if (!strcmp(name, "-"))
238		return (stdin);
239	if ((fp = fopen(name, "r")) == NULL) {
240		err(1, "%s", name);
241	}
242	return (fp);
243}
244
245static void
246usage(void)
247{
248	(void)fprintf(stderr, "usage: comm [-123i] file1 file2\n");
249	exit(1);
250}
251