xref: /dragonfly/usr.bin/from/from.c (revision 279dd846)
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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * @(#) Copyright (c) 1980, 1988, 1993 The Regents of the University of California.  All rights reserved.
30  * @(#)from.c	8.1 (Berkeley) 6/6/93
31  * $FreeBSD: src/usr.bin/from/from.c,v 1.8.2.1 2000/10/06 08:19:19 ru Exp $
32  * $DragonFly: src/usr.bin/from/from.c,v 1.5 2005/04/22 15:36:39 liamfoy Exp $
33  */
34 
35 #include <sys/types.h>
36 
37 #include <ctype.h>
38 #include <err.h>
39 #include <pwd.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <paths.h>
43 #include <string.h>
44 #include <unistd.h>
45 
46 static int	match(char *, char *);
47 static void	usage(void);
48 
49 int
50 main(int argc, char **argv)
51 {
52 	struct passwd *pwd;
53 	int ch, count, newline;
54 	const char *file;
55 	char *sender, *p;
56 #if MAXPATHLEN > BUFSIZ
57 	char buf[MAXPATHLEN];
58 #else
59 	char buf[BUFSIZ];
60 #endif
61 
62 	file = sender = NULL;
63 	count = -1;
64 	while ((ch = getopt(argc, argv, "cf:s:")) != -1)
65 		switch (ch) {
66 		case 'c':
67 			count = 0;
68 			break;
69 		case 'f':
70 			file = optarg;
71 			break;
72 		case 's':
73 			sender = optarg;
74 			for (p = sender; *p; ++p)
75 				*p = tolower(*p);
76 			break;
77 		case '?':
78 		default:
79 			usage();
80 		}
81 	argv += optind;
82 
83 	if (file == NULL) {
84 		if (*argv) {
85 			snprintf(buf, sizeof(buf), "%s/%s", _PATH_MAILDIR, *argv);
86 			file  = buf;
87 		} else {
88 			if ((file = getenv("MAIL")) == NULL) {
89 				if (!(pwd = getpwuid(getuid())))
90 					errx(1, "no password file entry for you");
91 				file = pwd->pw_name;
92 				snprintf(buf, sizeof(buf),
93 				    "%s/%s", _PATH_MAILDIR, file);
94 				file = buf;
95 			}
96 		}
97 	}
98 
99 	/* read from stdin */
100 	if (strcmp(file, "-") == 0) {
101 	}
102 	else if (freopen(file, "r", stdin) == NULL) {
103 		err(1, "can't read %s", file);
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 			if (count != -1)
113 				count++;
114 			else
115 				printf("%s", buf);
116 		}
117 		newline = 0;
118 	}
119 	if (count != -1)
120 		printf("There %s %d message%s in your incoming mailbox.\n",
121 		    count == 1 ? "is" : "are", count, count == 1 ? "" : "s");
122 	exit(0);
123 }
124 
125 static void
126 usage(void)
127 {
128 	fprintf(stderr, "usage: from [-c] [-f file] [-s sender] [user]\n");
129 	exit(1);
130 }
131 
132 static int
133 match(char *line, char *sender)
134 {
135 	char ch, pch, first, *p, *t;
136 
137 	for (first = *sender++;;) {
138 		if (isspace(ch = *line))
139 			return(0);
140 		++line;
141 		ch = tolower(ch);
142 		if (ch != first)
143 			continue;
144 		for (p = sender, t = line;;) {
145 			if (!(pch = *p++))
146 				return(1);
147 			ch = tolower(*t++);
148 			if (ch != pch)
149 				break;
150 		}
151 	}
152 	/* NOTREACHED */
153 }
154