BSD 4_3_Net_2 release

[unix-history] / usr / src / usr.bin / from / from.c

/*
* Copyright (c) 1980, 1988 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed by the University of
*      California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1980, 1988 The Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)from.c      5.7 (Berkeley) 3/1/91";
#endif /* not lint */

#include <sys/types.h>
#include <ctype.h>
#include <pwd.h>
#include <stdio.h>
#include <paths.h>

main(argc, argv)
       int argc;
       char **argv;
{
       extern char *optarg;
       extern int optind;
       struct passwd *pwd;
       int ch, newline;
       char *file, *sender, *p;
#if MAXPATHLEN > BUFSIZ
       char buf[MAXPATHLEN];
#else
       char buf[BUFSIZ];
#endif

       file = sender = NULL;
       while ((ch = getopt(argc, argv, "f:s:")) != EOF)
               switch((char)ch) {
               case 'f':
                       file = optarg;
                       break;
               case 's':
                       sender = optarg;
                       for (p = sender; *p; ++p)
                               if (isupper(*p))
                                       *p = tolower(*p);
                       break;
               case '?':
               default:
                       fprintf(stderr, "usage: from [-f file] [-s sender] [user]\n");
                       exit(1);
               }
       argv += optind;

       if (!file) {
               if (!(file = *argv)) {
                       if (!(pwd = getpwuid(getuid()))) {
                               fprintf(stderr,
                                   "from: no password file entry for you.\n");
                               exit(1);
                       }
                       file = pwd->pw_name;
               }
               (void)sprintf(buf, "%s/%s", _PATH_MAILDIR, file);
               file = buf;
       }
       if (!freopen(file, "r", stdin)) {
               fprintf(stderr, "from: can't read %s.\n", file);
               exit(1);
       }
       for (newline = 1; fgets(buf, sizeof(buf), stdin);) {
               if (*buf == '\n') {
                       newline = 1;
                       continue;
               }
               if (newline && !strncmp(buf, "From ", 5) &&
                   (!sender || match(buf + 5, sender)))
                       printf("%s", buf);
               newline = 0;
       }
       exit(0);
}

match(line, sender)
       register char *line, *sender;
{
       register char ch, pch, first, *p, *t;

       for (first = *sender++;;) {
               if (isspace(ch = *line))
                       return(0);
               ++line;
               if (isupper(ch))
                       ch = tolower(ch);
               if (ch != first)
                       continue;
               for (p = sender, t = line;;) {
                       if (!(pch = *p++))
                               return(1);
                       if (isupper(ch = *t++))
                               ch = tolower(ch);
                       if (ch != pch)
                               break;
               }
       }
       /* NOTREACHED */
}