xref: /freebsd/usr.bin/comm/comm.c (revision 6780ab54325a71e7e70112b11657973edde8655e)
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 <ctype.h>
53 #include <err.h>
54 #include <limits.h>
55 #include <locale.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include <unistd.h>
60 
61 #define	MAXLINELEN	(LINE_MAX + 1)
62 
63 const char *tabs[] = { "", "\t", "\t\t" };
64 
65 FILE   *file(const char *);
66 void	show(FILE *, const char *, char *);
67 int     stricoll(const char *, const char *);
68 static void	usage(void);
69 
70 int
71 main(int argc, char *argv[])
72 {
73 	int comp, file1done = 0, file2done = 0, read1, read2;
74 	int ch, flag1, flag2, flag3, iflag;
75 	FILE *fp1, *fp2;
76 	const char *col1, *col2, *col3;
77 	char line1[MAXLINELEN], line2[MAXLINELEN];
78 	const char **p;
79 
80 	flag1 = flag2 = flag3 = 1;
81 	iflag = 0;
82 
83 	(void) setlocale(LC_ALL, "");
84 
85 	while ((ch = getopt(argc, argv, "123i")) != -1)
86 		switch(ch) {
87 		case '1':
88 			flag1 = 0;
89 			break;
90 		case '2':
91 			flag2 = 0;
92 			break;
93 		case '3':
94 			flag3 = 0;
95 			break;
96 		case 'i':
97 			iflag = 1;
98 			break;
99 		case '?':
100 		default:
101 			usage();
102 		}
103 	argc -= optind;
104 	argv += optind;
105 
106 	if (argc != 2)
107 		usage();
108 
109 	fp1 = file(argv[0]);
110 	fp2 = file(argv[1]);
111 
112 	/* for each column printed, add another tab offset */
113 	p = tabs;
114 	col1 = col2 = col3 = NULL;
115 	if (flag1)
116 		col1 = *p++;
117 	if (flag2)
118 		col2 = *p++;
119 	if (flag3)
120 		col3 = *p;
121 
122 	for (read1 = read2 = 1;;) {
123 		/* read next line, check for EOF */
124 		if (read1)
125 			file1done = !fgets(line1, MAXLINELEN, fp1);
126 		if (read2)
127 			file2done = !fgets(line2, MAXLINELEN, fp2);
128 
129 		/* if one file done, display the rest of the other file */
130 		if (file1done) {
131 			if (!file2done && col2)
132 				show(fp2, col2, line2);
133 			break;
134 		}
135 		if (file2done) {
136 			if (!file1done && col1)
137 				show(fp1, col1, line1);
138 			break;
139 		}
140 
141 		/* lines are the same */
142 		if(iflag)
143 			comp = stricoll(line1, line2);
144 		else
145 			comp = strcoll(line1, line2);
146 
147 		if (!comp) {
148 			read1 = read2 = 1;
149 			if (col3)
150 				(void)printf("%s%s", col3, line1);
151 			continue;
152 		}
153 
154 		/* lines are different */
155 		if (comp < 0) {
156 			read1 = 1;
157 			read2 = 0;
158 			if (col1)
159 				(void)printf("%s%s", col1, line1);
160 		} else {
161 			read1 = 0;
162 			read2 = 1;
163 			if (col2)
164 				(void)printf("%s%s", col2, line2);
165 		}
166 	}
167 	exit(0);
168 }
169 
170 void
171 show(FILE *fp, const char *offset, char *buf)
172 {
173 
174 	do {
175 		(void)printf("%s%s", offset, buf);
176 	} while (fgets(buf, MAXLINELEN, fp));
177 }
178 
179 FILE *
180 file(const char *name)
181 {
182 	FILE *fp;
183 
184 	if (!strcmp(name, "-"))
185 		return (stdin);
186 	if ((fp = fopen(name, "r")) == NULL) {
187 		err(1, "%s", name);
188 	}
189 	return (fp);
190 }
191 
192 static void
193 usage(void)
194 {
195 	(void)fprintf(stderr, "usage: comm [-123i] file1 file2\n");
196 	exit(1);
197 }
198 
199 int
200 stricoll(const char *s1, const char *s2)
201 {
202 	char *p, line1[MAXLINELEN], line2[MAXLINELEN];
203 
204 	for (p = line1; *s1; s1++)
205 		*p++ = tolower((unsigned char)*s1);
206 	*p = '\0';
207 	for (p = line2; *s2; s2++)
208 		*p++ = tolower((unsigned char)*s2);
209 	*p = '\0';
210 	return strcoll(line1, line2);
211 }
212