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/* $OpenBSD: wall.c,v 1.32 2016/08/01 20:30:25 martijn Exp $ */ |
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/* $NetBSD: wall.c,v 1.6 1994/11/17 07:17:58 jtc Exp $ */ |
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/* |
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* Copyright (c) 1988, 1990, 1993 |
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* The Regents of the University of California. All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* 3. Neither the name of the University nor the names of its contributors |
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* may be used to endorse or promote products derived from this software |
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* without specific prior written permission. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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* SUCH DAMAGE. |
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*/ |
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/* |
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* This program is not related to David Wall, whose Stanford Ph.D. thesis |
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* is entitled "Mechanisms for Broadcast and Selective Broadcast". |
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*/ |
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#include <sys/queue.h> |
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#include <sys/stat.h> |
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#include <sys/time.h> |
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#include <sys/uio.h> |
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#include <ctype.h> |
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#include <err.h> |
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#include <grp.h> |
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#include <limits.h> |
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#include <paths.h> |
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#include <pwd.h> |
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#include <stdio.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <unistd.h> |
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#include <utmp.h> |
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struct wallgroup { |
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gid_t gid; |
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char *name; |
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char **mem; |
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struct wallgroup *next; |
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} *grouplist; |
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struct utmptty { |
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char *tty; |
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SLIST_ENTRY(utmptty) next; |
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}; |
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void makemsg(char *); |
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void addgroup(struct group *, char *); |
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char *ttymsg(struct iovec *, int, char *, int); |
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__dead void usage(void); |
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static int isu8cont(unsigned char); |
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int nobanner; |
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int mbufsize; |
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char *mbuf; |
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/* ARGSUSED */ |
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int |
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main(int argc, char **argv) |
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{ |
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FILE *fp; |
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int ch, ingroup; |
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struct iovec iov; |
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struct utmp utmp; |
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char *p, **mem; |
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char line[sizeof(utmp.ut_line) + 1]; |
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char username[sizeof(utmp.ut_name) + 1]; |
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struct passwd *pw; |
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struct group *grp; |
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struct wallgroup *g; |
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struct utmptty *un; |
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SLIST_HEAD(,utmptty) utmphead; |
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SLIST_INIT(&utmphead); |
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while ((ch = getopt(argc, argv, "ng:")) != -1) |
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switch (ch) { |
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case 'n': |
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/* undoc option for shutdown: suppress banner */ |
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pw = getpwnam("nobody"); |
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if (geteuid() == 0 || (pw && getuid() == pw->pw_uid)) |
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nobanner = 1; |
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break; |
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case 'g': |
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if ((grp = getgrnam(optarg)) == NULL) |
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errx(1, "unknown group `%s'", optarg); |
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addgroup(grp, optarg); |
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break; |
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default: |
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usage(); |
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} |
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argc -= optind; |
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argv += optind; |
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if (argc > 1) |
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usage(); |
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makemsg(*argv); |
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if (pledge("stdio rpath wpath getpw proc flock cpath", NULL) == -1) |
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err(1, "pledge"); |
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if (!(fp = fopen(_PATH_UTMP, "r"))) |
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err(1, "cannot read %s", _PATH_UTMP); |
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iov.iov_base = mbuf; |
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iov.iov_len = mbufsize; |
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while (fread(&utmp, sizeof(utmp), 1, fp) == 1) { |
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if (!utmp.ut_name[0]) |
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continue; |
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if (grouplist) { |
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ingroup = 0; |
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strncpy(username, utmp.ut_name, sizeof(utmp.ut_name)); |
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username[sizeof(utmp.ut_name)] = '\0'; |
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pw = getpwnam(username); |
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if (!pw) |
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continue; |
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for (g = grouplist; g && ingroup == 0; g = g->next) { |
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if (g->gid == pw->pw_gid) |
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ingroup = 1; |
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for (mem = g->mem; *mem && ingroup == 0; mem++) |
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if (strcmp(username, *mem) == 0) |
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ingroup = 1; |
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} |
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if (ingroup == 0) |
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continue; |
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} |
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strncpy(line, utmp.ut_line, sizeof(utmp.ut_line)); |
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line[sizeof(utmp.ut_line)] = '\0'; |
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un = malloc(sizeof(struct utmptty)); |
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if (un == NULL) |
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err(1, "malloc"); |
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un->tty = strndup(line, sizeof(utmp.ut_line)); |
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if (un->tty == NULL) |
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err(1, "strndup"); |
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SLIST_INSERT_HEAD(&utmphead, un, next); |
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} |
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fclose(fp); |
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if (pledge("stdio rpath wpath proc flock cpath", NULL) == -1) |
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err(1, "pledge"); |
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SLIST_FOREACH(un, &utmphead, next) { |
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if ((p = ttymsg(&iov, 1, un->tty, 60*5)) != NULL) |
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warnx("%s", p); |
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} |
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exit(0); |
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} |
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void |
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makemsg(char *fname) |
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{ |
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int cnt; |
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struct tm *lt; |
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struct passwd *pw; |
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struct stat sbuf; |
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time_t now; |
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FILE *fp; |
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int fd; |
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char *p, *whom, hostname[HOST_NAME_MAX+1], lbuf[100], tmpname[PATH_MAX]; |
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char *ttynam; |
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unsigned char ch; |
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snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXXXXXX", _PATH_TMP); |
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if ((fd = mkstemp(tmpname)) >= 0) { |
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(void)unlink(tmpname); |
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fp = fdopen(fd, "r+"); |
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} |
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if (fd == -1 || fp == NULL) |
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err(1, "can't open temporary file"); |
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if (!nobanner) { |
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if (!(whom = getlogin())) |
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whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???"; |
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(void)gethostname(hostname, sizeof(hostname)); |
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(void)time(&now); |
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lt = localtime(&now); |
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if ((ttynam = ttyname(STDERR_FILENO)) == NULL) |
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ttynam = "(not a tty)"; |
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/* |
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* all this stuff is to blank out a square for the message; |
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* we wrap message lines at column 79, not 80, because some |
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* terminals wrap after 79, some do not, and we can't tell. |
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* Which means that we may leave a non-blank character |
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* in column 80, but that can't be helped. |
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*/ |
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(void)fprintf(fp, "\r%79s\r\n", " "); |
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(void)snprintf(lbuf, sizeof lbuf, |
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"Broadcast Message from %s@%s", whom, hostname); |
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(void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf); |
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(void)snprintf(lbuf, sizeof lbuf, |
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" (%s) at %d:%02d ...", ttynam, |
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lt->tm_hour, lt->tm_min); |
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(void)fprintf(fp, "%-79.79s\r\n", lbuf); |
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} |
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(void)fprintf(fp, "%79s\r\n", " "); |
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if (fname) { |
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gid_t egid = getegid(); |
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setegid(getgid()); |
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if (freopen(fname, "r", stdin) == NULL) |
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err(1, "can't read %s", fname); |
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setegid(egid); |
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} |
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while (fgets(lbuf, sizeof(lbuf), stdin)) |
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for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) { |
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if (cnt == 79 || ch == '\n') { |
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for (; cnt < 79; ++cnt) |
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putc(' ', fp); |
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putc('\r', fp); |
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putc('\n', fp); |
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cnt = -1; |
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} else if (!isu8cont(ch)) |
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putc(isprint(ch) || isspace(ch) || ch == '\a' ? |
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ch : '?', fp); |
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} |
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(void)fprintf(fp, "%79s\r\n", " "); |
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rewind(fp); |
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if (fstat(fd, &sbuf)) |
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err(1, "can't stat temporary file"); |
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mbufsize = sbuf.st_size; |
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mbuf = malloc((u_int)mbufsize); |
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if (mbuf == NULL) |
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err(1, NULL); |
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if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize) |
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err(1, "can't read temporary file"); |
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(void)close(fd); |
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} |
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void |
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addgroup(struct group *grp, char *name) |
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{ |
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int i; |
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struct wallgroup *g; |
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for (i = 0; grp->gr_mem[i]; i++) |
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; |
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g = malloc(sizeof *g); |
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if (g == NULL) |
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err(1, NULL); |
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g->gid = grp->gr_gid; |
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g->name = name; |
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g->mem = calloc(i + 1, sizeof(char *)); |
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if (g->mem == NULL) |
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err(1, NULL); |
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for (i = 0; grp->gr_mem[i] != NULL; i++) { |
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g->mem[i] = strdup(grp->gr_mem[i]); |
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if (g->mem[i] == NULL) |
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err(1, NULL); |
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} |
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g->mem[i] = NULL; |
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g->next = grouplist; |
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grouplist = g; |
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} |
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void |
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usage(void) |
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{ |
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extern char *__progname; |
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(void)fprintf(stderr, "usage: %s [-g group] [file]\n", __progname); |
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exit(1); |
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} |
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static int |
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isu8cont(unsigned char c) |
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{ |
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return (c & (0x80 | 0x40)) == 0x80; |
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} |