xref: /freebsd/usr.bin/from/from.c (revision 4cf49a43559ed9fdad601bdcccd2c55963008675)
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
35 static 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
42 static char sccsid[] = "@(#)from.c	8.1 (Berkeley) 6/6/93";
43 #endif
44 static const char rcsid[] =
45   "$FreeBSD$";
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 
58 int match __P((char *, char *));
59 static void usage __P((void));
60 
61 int
62 main(argc, argv)
63 	int argc;
64 	char **argv;
65 {
66 	extern char *optarg;
67 	extern int optind;
68 	struct passwd *pwd;
69 	int ch, count, 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 	count = -1;
79 	while ((ch = getopt(argc, argv, "cf:s:")) != -1)
80 		switch (ch) {
81 		case 'c':
82 			count = 0;
83 			break;
84 		case 'f':
85 			file = optarg;
86 			break;
87 		case 's':
88 			sender = optarg;
89 			for (p = sender; *p; ++p)
90 				if (isupper(*p))
91 					*p = tolower(*p);
92 			break;
93 		case '?':
94 		default:
95 			usage();
96 		}
97 	argv += optind;
98 
99 	if (!file) {
100 		if (*argv) {
101 			(void)sprintf(buf, "%s/%s", _PATH_MAILDIR, *argv);
102 			file  = buf;
103 		} else {
104 			if (!(file = getenv("MAIL"))) {
105 				if (!(pwd = getpwuid(getuid())))
106 					errx(1, "no password file entry for you");
107 				file = pwd->pw_name;
108 				(void)sprintf(buf,
109 				    "%s/%s", _PATH_MAILDIR, file);
110 				file = buf;
111 			}
112 		}
113 	}
114 
115 	/* read from stdin */
116 	if (strcmp(file, "-") == 0) {
117 	}
118 	else if (!freopen(file, "r", stdin)) {
119 		errx(1, "can't read %s", file);
120 	}
121 	for (newline = 1; fgets(buf, sizeof(buf), stdin);) {
122 		if (*buf == '\n') {
123 			newline = 1;
124 			continue;
125 		}
126 		if (newline && !strncmp(buf, "From ", 5) &&
127 		    (!sender || match(buf + 5, sender))) {
128 			if (count != -1)
129 				count++;
130 			else
131 				printf("%s", buf);
132 		}
133 		newline = 0;
134 	}
135 	if (count != -1)
136 		printf("There %s %d message%s in your incoming mailbox.\n",
137 		    count == 1 ? "is" : "are", count, count == 1 ? "" : "s");
138 	exit(0);
139 }
140 
141 static void
142 usage()
143 {
144 	fprintf(stderr, "usage: from [-c] [-f file] [-s sender] [user]\n");
145 	exit(1);
146 }
147 
148 int
149 match(line, sender)
150 	register char *line, *sender;
151 {
152 	register char ch, pch, first, *p, *t;
153 
154 	for (first = *sender++;;) {
155 		if (isspace(ch = *line))
156 			return(0);
157 		++line;
158 		if (isupper(ch))
159 			ch = tolower(ch);
160 		if (ch != first)
161 			continue;
162 		for (p = sender, t = line;;) {
163 			if (!(pch = *p++))
164 				return(1);
165 			if (isupper(ch = *t++))
166 				ch = tolower(ch);
167 			if (ch != pch)
168 				break;
169 		}
170 	}
171 	/* NOTREACHED */
172 }
173