xref: /netbsd-src/usr.bin/from/from.c (revision 0b9f50897e9a9c6709320fafb4c3787fddcc0a45)
1 /*
2  * Copyright (c) 1980, 1988 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 char copyright[] =
36 "@(#) Copyright (c) 1980, 1988 The Regents of the University of California.\n\
37  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 /*static char sccsid[] = "from: @(#)from.c	5.7 (Berkeley) 3/1/91";*/
42 static char rcsid[] = "$Id: from.c,v 1.2 1993/08/01 18:15:43 mycroft Exp $";
43 #endif /* not lint */
44 
45 #include <sys/types.h>
46 #include <ctype.h>
47 #include <pwd.h>
48 #include <stdio.h>
49 #include <paths.h>
50 
51 main(argc, argv)
52 	int argc;
53 	char **argv;
54 {
55 	extern char *optarg;
56 	extern int optind;
57 	struct passwd *pwd;
58 	int ch, newline;
59 	char *file, *sender, *p;
60 #if MAXPATHLEN > BUFSIZ
61 	char buf[MAXPATHLEN];
62 #else
63 	char buf[BUFSIZ];
64 #endif
65 
66 	file = sender = NULL;
67 	while ((ch = getopt(argc, argv, "f:s:")) != EOF)
68 		switch((char)ch) {
69 		case 'f':
70 			file = optarg;
71 			break;
72 		case 's':
73 			sender = optarg;
74 			for (p = sender; *p; ++p)
75 				if (isupper(*p))
76 					*p = tolower(*p);
77 			break;
78 		case '?':
79 		default:
80 			fprintf(stderr, "usage: from [-f file] [-s sender] [user]\n");
81 			exit(1);
82 		}
83 	argv += optind;
84 
85 	if (!file) {
86 		if (!(file = *argv)) {
87 			if (!(pwd = getpwuid(getuid()))) {
88 				fprintf(stderr,
89 				    "from: no password file entry for you.\n");
90 				exit(1);
91 			}
92 			file = pwd->pw_name;
93 		}
94 		(void)sprintf(buf, "%s/%s", _PATH_MAILDIR, file);
95 		file = buf;
96 	}
97 	if (!freopen(file, "r", stdin)) {
98 		fprintf(stderr, "from: can't read %s.\n", file);
99 		exit(1);
100 	}
101 	for (newline = 1; fgets(buf, sizeof(buf), stdin);) {
102 		if (*buf == '\n') {
103 			newline = 1;
104 			continue;
105 		}
106 		if (newline && !strncmp(buf, "From ", 5) &&
107 		    (!sender || match(buf + 5, sender)))
108 			printf("%s", buf);
109 		newline = 0;
110 	}
111 	exit(0);
112 }
113 
114 match(line, sender)
115 	register char *line, *sender;
116 {
117 	register char ch, pch, first, *p, *t;
118 
119 	for (first = *sender++;;) {
120 		if (isspace(ch = *line))
121 			return(0);
122 		++line;
123 		if (isupper(ch))
124 			ch = tolower(ch);
125 		if (ch != first)
126 			continue;
127 		for (p = sender, t = line;;) {
128 			if (!(pch = *p++))
129 				return(1);
130 			if (isupper(ch = *t++))
131 				ch = tolower(ch);
132 			if (ch != pch)
133 				break;
134 		}
135 	}
136 	/* NOTREACHED */
137 }
138