/usr.bin/from/from.c

  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 * 4. 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
 30#ifndef lint
 31static const char copyright[] =
 32"@(#) Copyright (c) 1980, 1988, 1993\n\
 33	The Regents of the University of California.  All rights reserved.\n";
 34#endif /* not lint */
 35
 36#ifndef lint
 37#if 0
 38static char sccsid[] = "@(#)from.c	8.1 (Berkeley) 6/6/93";
 39#endif
 40#endif /* not lint */
 41#include <sys/cdefs.h>
 42__FBSDID("$FreeBSD$");
 43
 44#include <sys/types.h>
 45#include <ctype.h>
 46#include <err.h>
 47#include <pwd.h>
 48#include <stdio.h>
 49#include <stdlib.h>
 50#include <paths.h>
 51#include <string.h>
 52#include <unistd.h>
 53
 54int match(const char *, const char *);
 55static void usage(void);
 56
 57int
 58main(int argc, char **argv)
 59{
 60	FILE *mbox;
 61	struct passwd *pwd;
 62	int ch, count, newline;
 63	const char *file;
 64	char *sender, *p;
 65#if MAXPATHLEN > BUFSIZ
 66	char buf[MAXPATHLEN];
 67#else
 68	char buf[BUFSIZ];
 69#endif
 70
 71	file = sender = NULL;
 72	count = -1;
 73	while ((ch = getopt(argc, argv, "cf:s:")) != -1)
 74		switch (ch) {
 75		case 'c':
 76			count = 0;
 77			break;
 78		case 'f':
 79			file = optarg;
 80			break;
 81		case 's':
 82			sender = optarg;
 83			for (p = sender; *p; ++p)
 84				if (isupper(*p))
 85					*p = tolower(*p);
 86			break;
 87		case '?':
 88		default:
 89			usage();
 90		}
 91	argc -= optind;
 92	argv += optind;
 93
 94	if (file == NULL) {
 95		if (argc) {
 96			(void)snprintf(buf, sizeof(buf), "%s/%s", _PATH_MAILDIR, *argv);
 97			file  = buf;
 98		} else {
 99			if (!(file = getenv("MAIL"))) {
100				if (!(pwd = getpwuid(getuid())))
101					errx(1, "no password file entry for you");
102				file = pwd->pw_name;
103				(void)snprintf(buf, sizeof(buf),
104				    "%s/%s", _PATH_MAILDIR, file);
105				file = buf;
106			}
107		}
108	}
109
110	/* read from stdin */
111	if (strcmp(file, "-") == 0) {
112		mbox = stdin;
113	} 
114	else if ((mbox = fopen(file, "r")) == NULL) {
115		errx(1, "can't read %s", file);
116	}
117	for (newline = 1; fgets(buf, sizeof(buf), mbox);) {
118		if (*buf == '\n') {
119			newline = 1;
120			continue;
121		}
122		if (newline && !strncmp(buf, "From ", 5) &&
123		    (!sender || match(buf + 5, sender))) {
124			if (count != -1)
125				count++;
126			else
127				printf("%s", buf);
128		}
129		newline = 0;
130	}
131	if (count != -1)
132		printf("There %s %d message%s in your incoming mailbox.\n",
133		    count == 1 ? "is" : "are", count, count == 1 ? "" : "s"); 
134	fclose(mbox);
135	exit(0);
136}
137
138static void
139usage(void)
140{
141	fprintf(stderr, "usage: from [-c] [-f file] [-s sender] [user]\n");
142	exit(1);
143}
144
145int
146match(const char *line, const char *sender)
147{
148	char ch, pch, first;
149	const char *p, *t;
150
151	for (first = *sender++;;) {
152		if (isspace(ch = *line))
153			return(0);
154		++line;
155		if (isupper(ch))
156			ch = tolower(ch);
157		if (ch != first)
158			continue;
159		for (p = sender, t = line;;) {
160			if (!(pch = *p++))
161				return(1);
162			if (isupper(ch = *t++))
163				ch = tolower(ch);
164			if (ch != pch)
165				break;
166		}
167	}
168	/* NOTREACHED */
169}