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from.c revision 1.1 
      1 /*
      2  * Copyright (c) 1980, 1988 The Regents of the University of California.
      3  * 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 char copyright[] =
     36 "@(#) Copyright (c) 1980, 1988 The Regents of the University of California.\n\
     37  All rights reserved.\n";
     38 #endif /* not lint */
     39 
     40 #ifndef lint
     41 static char sccsid[] = "@(#)from.c	5.7 (Berkeley) 3/1/91";
     42 #endif /* not lint */
     43 
     44 #include <sys/types.h>
     45 #include <ctype.h>
     46 #include <pwd.h>
     47 #include <stdio.h>
     48 #include <paths.h>
     49 
     50 main(argc, argv)
     51 	int argc;
     52 	char **argv;
     53 {
     54 	extern char *optarg;
     55 	extern int optind;
     56 	struct passwd *pwd;
     57 	int ch, newline;
     58 	char *file, *sender, *p;
     59 #if MAXPATHLEN > BUFSIZ
     60 	char buf[MAXPATHLEN];
     61 #else
     62 	char buf[BUFSIZ];
     63 #endif
     64 
     65 	file = sender = NULL;
     66 	while ((ch = getopt(argc, argv, "f:s:")) != EOF)
     67 		switch((char)ch) {
     68 		case 'f':
     69 			file = optarg;
     70 			break;
     71 		case 's':
     72 			sender = optarg;
     73 			for (p = sender; *p; ++p)
     74 				if (isupper(*p))
     75 					*p = tolower(*p);
     76 			break;
     77 		case '?':
     78 		default:
     79 			fprintf(stderr, "usage: from [-f file] [-s sender] [user]\n");
     80 			exit(1);
     81 		}
     82 	argv += optind;
     83 
     84 	if (!file) {
     85 		if (!(file = *argv)) {
     86 			if (!(pwd = getpwuid(getuid()))) {
     87 				fprintf(stderr,
     88 				    "from: no password file entry for you.\n");
     89 				exit(1);
     90 			}
     91 			file = pwd->pw_name;
     92 		}
     93 		(void)sprintf(buf, "%s/%s", _PATH_MAILDIR, file);
     94 		file = buf;
     95 	}
     96 	if (!freopen(file, "r", stdin)) {
     97 		fprintf(stderr, "from: can't read %s.\n", file);
     98 		exit(1);
     99 	}
    100 	for (newline = 1; fgets(buf, sizeof(buf), stdin);) {
    101 		if (*buf == '\n') {
    102 			newline = 1;
    103 			continue;
    104 		}
    105 		if (newline && !strncmp(buf, "From ", 5) &&
    106 		    (!sender || match(buf + 5, sender)))
    107 			printf("%s", buf);
    108 		newline = 0;
    109 	}
    110 	exit(0);
    111 }
    112 
    113 match(line, sender)
    114 	register char *line, *sender;
    115 {
    116 	register char ch, pch, first, *p, *t;
    117 
    118 	for (first = *sender++;;) {
    119 		if (isspace(ch = *line))
    120 			return(0);
    121 		++line;
    122 		if (isupper(ch))
    123 			ch = tolower(ch);
    124 		if (ch != first)
    125 			continue;
    126 		for (p = sender, t = line;;) {
    127 			if (!(pch = *p++))
    128 				return(1);
    129 			if (isupper(ch = *t++))
    130 				ch = tolower(ch);
    131 			if (ch != pch)
    132 				break;
    133 		}
    134 	}
    135 	/* NOTREACHED */
    136 }
    137