xref: /netbsd-src/usr.bin/from/from.c (revision 76dfffe33547c37f8bdd446e3e4ab0f3c16cea4b)
1 /*	$NetBSD: from.c,v 1.6 1995/09/01 01:39:10 jtc 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 #ifndef lint
37 static char copyright[] =
38 "@(#) 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 static char rcsid[] = "$NetBSD: from.c,v 1.6 1995/09/01 01:39:10 jtc Exp $";
47 #endif /* not lint */
48 
49 #include <sys/types.h>
50 #include <ctype.h>
51 #include <pwd.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <unistd.h>
55 #include <paths.h>
56 
57 main(argc, argv)
58 	int argc;
59 	char **argv;
60 {
61 	extern char *optarg;
62 	extern int optind;
63 	struct passwd *pwd;
64 	int ch, newline;
65 	char *file, *sender, *p;
66 #if MAXPATHLEN > BUFSIZ
67 	char buf[MAXPATHLEN];
68 #else
69 	char buf[BUFSIZ];
70 #endif
71 
72 	file = sender = NULL;
73 	while ((ch = getopt(argc, argv, "f:s:")) != EOF)
74 		switch((char)ch) {
75 		case 'f':
76 			file = optarg;
77 			break;
78 		case 's':
79 			sender = optarg;
80 			for (p = sender; *p; ++p)
81 				if (isupper(*p))
82 					*p = tolower(*p);
83 			break;
84 		case '?':
85 		default:
86 			fprintf(stderr, "usage: from [-f file] [-s sender] [user]\n");
87 			exit(1);
88 		}
89 	argv += optind;
90 
91 	/*
92 	 * We find the mailbox by:
93 	 *	1 -f flag
94 	 *	2 user
95 	 *	2 MAIL environment variable
96 	 *	3 _PATH_MAILDIR/file
97 	 */
98 	if (!file) {
99 		if (!(file = *argv)) {
100 			if (!(file = getenv("MAIL"))) {
101 				if (!(pwd = getpwuid(getuid()))) {
102 					(void)fprintf(stderr,
103 				"from: no password file entry for you.\n");
104 					exit(1);
105 				}
106 				if (file = getenv("USER")) {
107 					(void)sprintf(buf, "%s/%s",
108 					    _PATH_MAILDIR, file);
109 					file = buf;
110 				} else
111 					(void)sprintf(file = buf, "%s/%s",
112 					    _PATH_MAILDIR, pwd->pw_name);
113 			}
114 		} else {
115 			(void)sprintf(buf, "%s/%s", _PATH_MAILDIR, file);
116 			file = buf;
117 		}
118 	}
119 	if (!freopen(file, "r", stdin)) {
120 		(void)fprintf(stderr, "from: can't read %s.\n", file);
121 		exit(1);
122 	}
123 	for (newline = 1; fgets(buf, sizeof(buf), stdin);) {
124 		if (*buf == '\n') {
125 			newline = 1;
126 			continue;
127 		}
128 		if (newline && !strncmp(buf, "From ", 5) &&
129 		    (!sender || match(buf + 5, sender)))
130 			printf("%s", buf);
131 		newline = 0;
132 	}
133 	exit(0);
134 }
135 
136 match(line, sender)
137 	register char *line, *sender;
138 {
139 	register char ch, pch, first, *p, *t;
140 
141 	for (first = *sender++;;) {
142 		if (isspace(ch = *line))
143 			return(0);
144 		++line;
145 		if (isupper(ch))
146 			ch = tolower(ch);
147 		if (ch != first)
148 			continue;
149 		for (p = sender, t = line;;) {
150 			if (!(pch = *p++))
151 				return(1);
152 			if (isupper(ch = *t++))
153 				ch = tolower(ch);
154 			if (ch != pch)
155 				break;
156 		}
157 	}
158 	/* NOTREACHED */
159 }
160