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  * 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  * @(#) Copyright (c) 1980, 1988, 1993 The Regents of the University of California.  All rights reserved.
  34  * @(#)from.c   8.1 (Berkeley) 6/6/93
  35  * $FreeBSD: src/usr.bin/from/from.c,v 1.8.2.1 2000/10/06 08:19:19 ru Exp $
  36  * $DragonFly: src/usr.bin/from/from.c,v 1.5 2005/04/22 15:36:39 liamfoy Exp $
  37  */
  38
  39 #include <sys/types.h>
  40
  41 #include <ctype.h>
  42 #include <err.h>
  43 #include <pwd.h>
  44 #include <stdio.h>
  45 #include <stdlib.h>
  46 #include <paths.h>
  47 #include <string.h>
  48 #include <unistd.h>
  49
  50 static int      match(char *, char *);
  51 static void     usage(void);
  52
  53 int
  54 main(int argc, char **argv)
  55 {
  56         struct passwd *pwd;
  57         int ch, count, newline;
  58         const char *file;
  59         char *sender, *p;
  60 #if MAXPATHLEN > BUFSIZ
  61         char buf[MAXPATHLEN];
  62 #else
  63         char buf[BUFSIZ];
  64 #endif
  65
  66         file = sender = NULL;
  67         count = -1;
  68         while ((ch = getopt(argc, argv, "cf:s:")) != -1)
  69                 switch (ch) {
  70                 case 'c':
  71                         count = 0;
  72                         break;
  73                 case 'f':
  74                         file = optarg;
  75                         break;
  76                 case 's':
  77                         sender = optarg;
  78                         for (p = sender; *p; ++p)
  79                                 *p = tolower(*p);
  80                         break;
  81                 case '?':
  82                 default:
  83                         usage();
  84                 }
  85         argv += optind;
  86
  87         if (file == NULL) {
  88                 if (*argv) {
  89                         snprintf(buf, sizeof(buf), "%s/%s", _PATH_MAILDIR, *argv);
  90                         file  = buf;
  91                 } else {
  92                         if ((file = getenv("MAIL")) == NULL) {
  93                                 if (!(pwd = getpwuid(getuid())))
  94                                         errx(1, "no password file entry for you");
  95                                 file = pwd->pw_name;
  96                                 snprintf(buf, sizeof(buf),
  97                                     "%s/%s", _PATH_MAILDIR, file);
  98                                 file = buf;
  99                         }
 100                 }
 101         }
 102
 103         /* read from stdin */
 104         if (strcmp(file, "-") == 0) {
 105         }
 106         else if (freopen(file, "r", stdin) == NULL) {
 107                 err(1, "can't read %s", file);
 108         }
 109         for (newline = 1; fgets(buf, sizeof(buf), stdin);) {
 110                 if (*buf == '\n') {
 111                         newline = 1;
 112                         continue;
 113                 }
 114                 if (newline && !strncmp(buf, "From ", 5) &&
 115                     (!sender || match(buf + 5, sender))) {
 116                         if (count != -1)
 117                                 count++;
 118                         else
 119                                 printf("%s", buf);
 120                 }
 121                 newline = 0;
 122         }
 123         if (count != -1)
 124                 printf("There %s %d message%s in your incoming mailbox.\n",
 125                     count == 1 ? "is" : "are", count, count == 1 ? "" : "s");
 126         exit(0);
 127 }
 128
 129 static void
 130 usage(void)
 131 {
 132         fprintf(stderr, "usage: from [-c] [-f file] [-s sender] [user]\n");
 133         exit(1);
 134 }
 135
 136 static int
 137 match(char *line, char *sender)
 138 {
 139         char ch, pch, first, *p, *t;
 140
 141         for (first = *sender++;;) {
 142                 if (isspace(ch = *line))
 143                         return(0);
 144                 ++line;
 145                 ch = tolower(ch);
 146                 if (ch != first)
 147                         continue;
 148                 for (p = sender, t = line;;) {
 149                         if (!(pch = *p++))
 150                                 return(1);
 151                         ch = tolower(*t++);
 152                         if (ch != pch)
 153                                 break;
 154                 }
 155         }
 156         /* NOTREACHED */
 157 }