xref: /freebsd/usr.bin/comm/comm.c (revision aa64588d28258aef88cc33b8043112e8856948d0)
1 /*
2  * Copyright (c) 1989, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Case Larsen.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #ifndef lint
38 static const char copyright[] =
39 "@(#) Copyright (c) 1989, 1993, 1994\n\
40 	The Regents of the University of California.  All rights reserved.\n";
41 #endif
42 
43 #if 0
44 #ifndef lint
45 static char sccsid[] = "From: @(#)comm.c	8.4 (Berkeley) 5/4/95";
46 #endif
47 #endif
48 
49 #include <sys/cdefs.h>
50 __FBSDID("$FreeBSD$");
51 
52 #include <err.h>
53 #include <limits.h>
54 #include <locale.h>
55 #include <stdint.h>
56 #define _WITH_GETLINE
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <unistd.h>
61 #include <wchar.h>
62 #include <wctype.h>
63 
64 int iflag;
65 const char *tabs[] = { "", "\t", "\t\t" };
66 
67 FILE   *file(const char *);
68 wchar_t	*convert(const char *);
69 void	show(FILE *, const char *, const char *, char **, size_t *);
70 static void	usage(void);
71 
72 int
73 main(int argc, char *argv[])
74 {
75 	int comp, read1, read2;
76 	int ch, flag1, flag2, flag3;
77 	FILE *fp1, *fp2;
78 	const char *col1, *col2, *col3;
79 	size_t line1len, line2len;
80 	char *line1, *line2;
81 	ssize_t n1, n2;
82 	wchar_t *tline1, *tline2;
83 	const char **p;
84 
85 	(void) setlocale(LC_ALL, "");
86 
87 	flag1 = flag2 = flag3 = 1;
88 
89 	while ((ch = getopt(argc, argv, "123i")) != -1)
90 		switch(ch) {
91 		case '1':
92 			flag1 = 0;
93 			break;
94 		case '2':
95 			flag2 = 0;
96 			break;
97 		case '3':
98 			flag3 = 0;
99 			break;
100 		case 'i':
101 			iflag = 1;
102 			break;
103 		case '?':
104 		default:
105 			usage();
106 		}
107 	argc -= optind;
108 	argv += optind;
109 
110 	if (argc != 2)
111 		usage();
112 
113 	fp1 = file(argv[0]);
114 	fp2 = file(argv[1]);
115 
116 	/* for each column printed, add another tab offset */
117 	p = tabs;
118 	col1 = col2 = col3 = NULL;
119 	if (flag1)
120 		col1 = *p++;
121 	if (flag2)
122 		col2 = *p++;
123 	if (flag3)
124 		col3 = *p;
125 
126 	line1len = line2len = 0;
127 	line1 = line2 = NULL;
128 	n1 = n2 = -1;
129 
130 	for (read1 = read2 = 1;;) {
131 		/* read next line, check for EOF */
132 		if (read1) {
133 			n1 = getline(&line1, &line1len, fp1);
134 			if (n1 < 0 && ferror(fp1))
135 				err(1, "%s", argv[0]);
136 			if (n1 > 0 && line1[n1 - 1] == '\n')
137 				line1[n1 - 1] = '\0';
138 
139 		}
140 		if (read2) {
141 			n2 = getline(&line2, &line2len, fp2);
142 			if (n2 < 0 && ferror(fp2))
143 				err(1, "%s", argv[1]);
144 			if (n2 > 0 && line2[n2 - 1] == '\n')
145 				line2[n2 - 1] = '\0';
146 		}
147 
148 		/* if one file done, display the rest of the other file */
149 		if (n1 < 0) {
150 			if (n2 >= 0 && col2 != NULL)
151 				show(fp2, argv[1], col2, &line2, &line2len);
152 			break;
153 		}
154 		if (n2 < 0) {
155 			if (n1 >= 0 && col1 != NULL)
156 				show(fp1, argv[0], col1, &line1, &line1len);
157 			break;
158 		}
159 
160 		tline2 = NULL;
161 		if ((tline1 = convert(line1)) != NULL)
162 			tline2 = convert(line2);
163 		if (tline1 == NULL || tline2 == NULL)
164 			comp = strcmp(line1, line2);
165 		else
166 			comp = wcscoll(tline1, tline2);
167 		if (tline1 != NULL)
168 			free(tline1);
169 		if (tline2 != NULL)
170 			free(tline2);
171 
172 		/* lines are the same */
173 		if (!comp) {
174 			read1 = read2 = 1;
175 			if (col3 != NULL)
176 				(void)printf("%s%s\n", col3, line1);
177 			continue;
178 		}
179 
180 		/* lines are different */
181 		if (comp < 0) {
182 			read1 = 1;
183 			read2 = 0;
184 			if (col1 != NULL)
185 				(void)printf("%s%s\n", col1, line1);
186 		} else {
187 			read1 = 0;
188 			read2 = 1;
189 			if (col2 != NULL)
190 				(void)printf("%s%s\n", col2, line2);
191 		}
192 	}
193 	exit(0);
194 }
195 
196 wchar_t *
197 convert(const char *str)
198 {
199 	size_t n;
200 	wchar_t *buf, *p;
201 
202 	if ((n = mbstowcs(NULL, str, 0)) == (size_t)-1)
203 		return (NULL);
204 	if (SIZE_MAX / sizeof(*buf) < n + 1)
205 		errx(1, "conversion buffer length overflow");
206 	if ((buf = malloc((n + 1) * sizeof(*buf))) == NULL)
207 		err(1, "malloc");
208 	if (mbstowcs(buf, str, n + 1) != n)
209 		errx(1, "internal mbstowcs() error");
210 
211 	if (iflag) {
212 		for (p = buf; *p != L'\0'; p++)
213 			*p = towlower(*p);
214 	}
215 
216 	return (buf);
217 }
218 
219 void
220 show(FILE *fp, const char *fn, const char *offset, char **bufp, size_t *buflenp)
221 {
222 	ssize_t n;
223 
224 	do {
225 		(void)printf("%s%s\n", offset, *bufp);
226 		if ((n = getline(bufp, buflenp, fp)) < 0)
227 			break;
228 		if (n > 0 && (*bufp)[n - 1] == '\n')
229 			(*bufp)[n - 1] = '\0';
230 	} while (1);
231 	if (ferror(fp))
232 		err(1, "%s", fn);
233 }
234 
235 FILE *
236 file(const char *name)
237 {
238 	FILE *fp;
239 
240 	if (!strcmp(name, "-"))
241 		return (stdin);
242 	if ((fp = fopen(name, "r")) == NULL) {
243 		err(1, "%s", name);
244 	}
245 	return (fp);
246 }
247 
248 static void
249 usage(void)
250 {
251 	(void)fprintf(stderr, "usage: comm [-123i] file1 file2\n");
252 	exit(1);
253 }
254