xref: /netbsd-src/usr.bin/from/from.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: from.c,v 1.8 1997/10/18 15:08:53 lukem Exp $	*/
2 
3 /*
4  * Copyright (c) 1980, 1988, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 __COPYRIGHT("@(#) Copyright (c) 1980, 1988, 1993\n\
39 	The Regents of the University of California.  All rights reserved.\n");
40 #endif /* not lint */
41 
42 #ifndef lint
43 #if 0
44 static char sccsid[] = "@(#)from.c	8.1 (Berkeley) 6/6/93";
45 #endif
46 __RCSID("$NetBSD: from.c,v 1.8 1997/10/18 15:08:53 lukem Exp $");
47 #endif /* not lint */
48 
49 #include <sys/types.h>
50 #include <ctype.h>
51 #include <paths.h>
52 #include <pwd.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <unistd.h>
57 
58 int	main __P((int, char **));
59 int	match __P((char *, char *));
60 
61 int
62 main(argc, argv)
63 	int argc;
64 	char **argv;
65 {
66 	struct passwd *pwd;
67 	int ch, newline;
68 	char *file, *sender, *p;
69 #if MAXPATHLEN > BUFSIZ
70 	char buf[MAXPATHLEN];
71 #else
72 	char buf[BUFSIZ];
73 #endif
74 
75 	file = sender = NULL;
76 	while ((ch = getopt(argc, argv, "f:s:")) != -1)
77 		switch((char)ch) {
78 		case 'f':
79 			file = optarg;
80 			break;
81 		case 's':
82 			sender = optarg;
83 			for (p = sender; *p; ++p)
84 				if (isupper(*p))
85 					*p = tolower(*p);
86 			break;
87 		case '?':
88 		default:
89 			fprintf(stderr, "usage: from [-f file] [-s sender] [user]\n");
90 			exit(1);
91 		}
92 	argv += optind;
93 
94 	/*
95 	 * We find the mailbox by:
96 	 *	1 -f flag
97 	 *	2 user
98 	 *	2 MAIL environment variable
99 	 *	3 _PATH_MAILDIR/file
100 	 */
101 	if (!file) {
102 		if (!(file = *argv)) {
103 			if (!(file = getenv("MAIL"))) {
104 				if (!(pwd = getpwuid(getuid()))) {
105 					(void)fprintf(stderr,
106 				"from: no password file entry for you.\n");
107 					exit(1);
108 				}
109 				if ((file = getenv("USER")) != NULL) {
110 					(void)sprintf(buf, "%s/%s",
111 					    _PATH_MAILDIR, file);
112 					file = buf;
113 				} else
114 					(void)sprintf(file = buf, "%s/%s",
115 					    _PATH_MAILDIR, pwd->pw_name);
116 			}
117 		} else {
118 			(void)sprintf(buf, "%s/%s", _PATH_MAILDIR, file);
119 			file = buf;
120 		}
121 	}
122 	if (!freopen(file, "r", stdin)) {
123 		(void)fprintf(stderr, "from: can't read %s.\n", file);
124 		exit(1);
125 	}
126 	for (newline = 1; fgets(buf, sizeof(buf), stdin);) {
127 		if (*buf == '\n') {
128 			newline = 1;
129 			continue;
130 		}
131 		if (newline && !strncmp(buf, "From ", 5) &&
132 		    (!sender || match(buf + 5, sender)))
133 			printf("%s", buf);
134 		newline = 0;
135 	}
136 	exit(0);
137 }
138 
139 int
140 match(line, sender)
141 	char *line, *sender;
142 {
143 	char ch, pch, first, *p, *t;
144 
145 	for (first = *sender++;;) {
146 		if (isspace(ch = *line))
147 			return(0);
148 		++line;
149 		if (isupper(ch))
150 			ch = tolower(ch);
151 		if (ch != first)
152 			continue;
153 		for (p = sender, t = line;;) {
154 			if (!(pch = *p++))
155 				return(1);
156 			if (isupper(ch = *t++))
157 				ch = tolower(ch);
158 			if (ch != pch)
159 				break;
160 		}
161 	}
162 	/* NOTREACHED */
163 }
164