from.c revision 13678 
1/*
2 * Copyright (c) 1980, 1988, 1993
3 *	The Regents of the University of California.  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
35static char copyright[] =
36"@(#) Copyright (c) 1980, 1988, 1993\n\
37	The Regents of the University of California.  All rights reserved.\n";
38#endif /* not lint */
39
40#ifndef lint
41static char sccsid[] = "@(#)from.c	8.1 (Berkeley) 6/6/93";
42#endif /* not lint */
43
44#include <sys/types.h>
45#include <ctype.h>
46#include <pwd.h>
47#include <stdio.h>
48#include <string.h>
49#include <paths.h>
50
51main(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
98	/* read from stdin */
99	if (strcmp(file, "-") == 0) {
100	}
101	else if (!freopen(file, "r", stdin)) {
102		fprintf(stderr, "from: can't read %s.\n", file);
103		exit(1);
104	}
105	for (newline = 1; fgets(buf, sizeof(buf), stdin);) {
106		if (*buf == '\n') {
107			newline = 1;
108			continue;
109		}
110		if (newline && !strncmp(buf, "From ", 5) &&
111		    (!sender || match(buf + 5, sender)))
112			printf("%s", buf);
113		newline = 0;
114	}
115	exit(0);
116}
117
118match(line, sender)
119	register char *line, *sender;
120{
121	register char ch, pch, first, *p, *t;
122
123	for (first = *sender++;;) {
124		if (isspace(ch = *line))
125			return(0);
126		++line;
127		if (isupper(ch))
128			ch = tolower(ch);
129		if (ch != first)
130			continue;
131		for (p = sender, t = line;;) {
132			if (!(pch = *p++))
133				return(1);
134			if (isupper(ch = *t++))
135				ch = tolower(ch);
136			if (ch != pch)
137				break;
138		}
139	}
140	/* NOTREACHED */
141}
142