xref: /openbsd-src/usr.bin/from/from.c (revision daf88648c0e349d5c02e1504293082072c981640)
1 /*	$OpenBSD: from.c,v 1.12 2006/03/14 19:39:49 moritz Exp $	*/
2 /*	$NetBSD: from.c,v 1.6 1995/09/01 01:39:10 jtc Exp $	*/
3 
4 /*
5  * Copyright (c) 1980, 1988, 1993
6  *	The Regents of the University of California.  All rights reserved.
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. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #ifndef lint
34 static char copyright[] =
35 "@(#) Copyright (c) 1980, 1988, 1993\n\
36 	The Regents of the University of California.  All rights reserved.\n";
37 #endif /* not lint */
38 
39 #ifndef lint
40 #if 0
41 static char sccsid[] = "@(#)from.c	8.1 (Berkeley) 6/6/93";
42 #endif
43 static char rcsid[] = "$OpenBSD: from.c,v 1.12 2006/03/14 19:39:49 moritz Exp $";
44 #endif /* not lint */
45 
46 #include <sys/types.h>
47 #include <ctype.h>
48 #include <pwd.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <unistd.h>
52 #include <paths.h>
53 #include <string.h>
54 #include <err.h>
55 
56 int	match(char *, char *);
57 
58 int
59 main(int argc, char *argv[])
60 {
61 	struct passwd *pwd;
62 	int ch, newline;
63 	char *file, *sender, *p;
64 #if MAXPATHLEN > BUFSIZ
65 	char buf[MAXPATHLEN];
66 #else
67 	char buf[BUFSIZ];
68 #endif
69 
70 	file = sender = NULL;
71 	while ((ch = getopt(argc, argv, "f:s:")) != -1)
72 		switch((char)ch) {
73 		case 'f':
74 			file = optarg;
75 			break;
76 		case 's':
77 			sender = optarg;
78 			for (p = sender; *p; ++p)
79 				if (isupper(*p))
80 					*p = tolower(*p);
81 			break;
82 		case '?':
83 		default:
84 			fprintf(stderr, "usage: from [-f file] [-s sender] [user]\n");
85 			exit(1);
86 		}
87 	argv += optind;
88 
89 	/*
90 	 * We find the mailbox by:
91 	 *	1 -f flag
92 	 *	2 user
93 	 *	2 MAIL environment variable
94 	 *	3 _PATH_MAILDIR/file
95 	 */
96 	if (!file) {
97 		if (!(file = *argv)) {
98 			if (!(file = getenv("MAIL"))) {
99 				if (!(pwd = getpwuid(getuid())))
100 					errx(1, "no password file entry for you");
101 				if ((file = getenv("USER"))) {
102 					(void)snprintf(buf, sizeof(buf),
103 					    "%s/%s", _PATH_MAILDIR, file);
104 					file = buf;
105 				} else
106 					(void)snprintf(file = buf, sizeof(buf),
107 					    "%s/%s", _PATH_MAILDIR,
108 					    pwd->pw_name);
109 			}
110 		} else {
111 			(void)snprintf(buf, sizeof(buf), "%s/%s",
112 			    _PATH_MAILDIR, file);
113 			file = buf;
114 		}
115 	}
116 	if (!freopen(file, "r", stdin))
117 		err(1, "%s", file);
118 	for (newline = 1; fgets(buf, sizeof(buf), stdin);) {
119 		if (*buf == '\n') {
120 			newline = 1;
121 			continue;
122 		}
123 		if (newline && !strncmp(buf, "From ", 5) &&
124 		    (!sender || match(buf + 5, sender)))
125 			printf("%s", buf);
126 		newline = 0;
127 	}
128 	exit(0);
129 }
130 
131 int
132 match(char *line, char *sender)
133 {
134 	char ch, pch, first, *p, *t;
135 
136 	for (first = *sender++;;) {
137 		if (isspace(ch = *line))
138 			return(0);
139 		++line;
140 		if (isupper(ch))
141 			ch = tolower(ch);
142 		if (ch != first)
143 			continue;
144 		for (p = sender, t = line;;) {
145 			if (!(pch = *p++))
146 				return(1);
147 			if (isupper(ch = *t++))
148 				ch = tolower(ch);
149 			if (ch != pch)
150 				break;
151 		}
152 	}
153 	/* NOTREACHED */
154 }
155