from.c revision 27270 
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 const 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
41#if 0
42static char sccsid[] = "@(#)from.c	8.1 (Berkeley) 6/6/93";
43#endif
44static const char rcsid[] =
45	"$Id$";
46#endif /* not lint */
47
48#include <sys/types.h>
49#include <ctype.h>
50#include <err.h>
51#include <pwd.h>
52#include <stdio.h>
53#include <stdlib.h>
54#include <paths.h>
55#include <string.h>
56#include <unistd.h>
57
58int match __P((char *, char *));
59static void usage __P((void));
60
61int
62main(argc, argv)
63	int argc;
64	char **argv;
65{
66	extern char *optarg;
67	extern int optind;
68	struct passwd *pwd;
69	int ch, newline;
70	char *file, *sender, *p;
71#if MAXPATHLEN > BUFSIZ
72	char buf[MAXPATHLEN];
73#else
74	char buf[BUFSIZ];
75#endif
76
77	file = sender = NULL;
78	while ((ch = getopt(argc, argv, "f:s:")) != -1)
79		switch((char)ch) {
80		case 'f':
81			file = optarg;
82			break;
83		case 's':
84			sender = optarg;
85			for (p = sender; *p; ++p)
86				if (isupper(*p))
87					*p = tolower(*p);
88			break;
89		case '?':
90		default:
91			usage();
92		}
93	argv += optind;
94
95	if (!file) {
96		if (*argv) {
97			(void)sprintf(buf, "%s/%s", _PATH_MAILDIR, *argv);
98			file  = buf;
99		} else {
100			if (!(file = getenv("MAIL"))) {
101				if (!(pwd = getpwuid(getuid())))
102					errx(1, "no password file entry for you");
103				file = pwd->pw_name;
104				(void)sprintf(buf,
105				    "%s/%s", _PATH_MAILDIR, file);
106				file = buf;
107			}
108		}
109	}
110
111	/* read from stdin */
112	if (strcmp(file, "-") == 0) {
113	}
114	else if (!freopen(file, "r", stdin)) {
115		errx(1, "can't read %s", file);
116	}
117	for (newline = 1; fgets(buf, sizeof(buf), stdin);) {
118		if (*buf == '\n') {
119			newline = 1;
120			continue;
121		}
122		if (newline && !strncmp(buf, "From ", 5) &&
123		    (!sender || match(buf + 5, sender)))
124			printf("%s", buf);
125		newline = 0;
126	}
127	exit(0);
128}
129
130static void
131usage()
132{
133	fprintf(stderr, "usage: from [-f file] [-s sender] [user]\n");
134	exit(1);
135}
136
137int
138match(line, sender)
139	register char *line, *sender;
140{
141	register char ch, pch, first, *p, *t;
142
143	for (first = *sender++;;) {
144		if (isspace(ch = *line))
145			return(0);
146		++line;
147		if (isupper(ch))
148			ch = tolower(ch);
149		if (ch != first)
150			continue;
151		for (p = sender, t = line;;) {
152			if (!(pch = *p++))
153				return(1);
154			if (isupper(ch = *t++))
155				ch = tolower(ch);
156			if (ch != pch)
157				break;
158		}
159	}
160	/* NOTREACHED */
161}
162