pwd was undefined when user was unknown for remote login
[unix-history] / usr / src / usr.bin / login / login.c
CommitLineData
22d4760e 1#ifndef lint
4cf9fc9e 2static char *sccsid = "@(#)login.c 4.31 (Berkeley) 83/06/30";
22d4760e
SL
3#endif
4
88a01c09
BJ
5/*
6 * login [ name ]
3b8dd95e
SL
7 * login -r hostname (for rlogind)
8 * login -h hostname (for telnetd, etc.)
88a01c09
BJ
9 */
10
7a625b73 11#include <sys/param.h>
3b8dd95e
SL
12#include <sys/quota.h>
13#include <sys/stat.h>
14#include <sys/time.h>
15#include <sys/resource.h>
16
88a01c09
BJ
17#include <sgtty.h>
18#include <utmp.h>
19#include <signal.h>
20#include <pwd.h>
21#include <stdio.h>
88a01c09 22#include <lastlog.h>
22d4760e 23#include <errno.h>
f570e1ff
BJ
24
25#define SCPYN(a, b) strncpy(a, b, sizeof(a))
88a01c09 26
b4389814 27#define NMAX sizeof(utmp.ut_name)
88a01c09 28
f570e1ff
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29#define FALSE 0
30#define TRUE -1
31
32char nolog[] = "/etc/nologin";
33char qlog[] = ".hushlogin";
34char securetty[] = "/etc/securetty";
88a01c09
BJ
35char maildir[30] = "/usr/spool/mail/";
36char lastlog[] = "/usr/adm/lastlog";
3479a16a 37struct passwd nouser = {"", "nope", -1, -1, -1, "", "", "", "" };
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BJ
38struct sgttyb ttyb;
39struct utmp utmp;
40char minusnam[16] = "-";
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SL
41/*
42 * This bounds the time given to login. We initialize it here
43 * so it can be patched on machines where it's too small.
44 */
45int timeout = 60;
86eb6c9e 46
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BJ
47char homedir[64] = "HOME=";
48char shell[64] = "SHELL=";
49char term[64] = "TERM=";
f570e1ff 50char user[20] = "USER=";
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51
52char *envinit[] =
3b8dd95e 53 { homedir, shell, "PATH=:/usr/ucb:/bin:/usr/bin", term, user, 0 };
88a01c09 54
86eb6c9e 55struct passwd *pwd;
88a01c09 56struct passwd *getpwnam();
86eb6c9e 57char *strcat(), *rindex(), *index();
88a01c09 58int setpwent();
3b8dd95e 59int timedout();
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BJ
60char *ttyname();
61char *crypt();
62char *getpass();
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63char *stypeof();
64extern char **environ;
22d4760e 65extern int errno;
88a01c09 66
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SL
67struct tchars tc = {
68 CINTR, CQUIT, CSTART, CSTOP, CEOT, CBRK
69};
70struct ltchars ltc = {
71 CSUSP, CDSUSP, CRPRNT, CFLUSH, CWERASE, CLNEXT
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BJ
72};
73
86eb6c9e 74int rflag;
b4389814 75char rusername[NMAX+1], lusername[NMAX+1];
86eb6c9e 76char rpassword[NMAX+1];
e5321f7b 77char name[NMAX+1];
b4389814 78char *rhost;
86eb6c9e 79
88a01c09 80main(argc, argv)
3b8dd95e 81 char *argv[];
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BJ
82{
83 register char *namep;
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SL
84 int t, f, c, i;
85 int invalid, quietlog;
f570e1ff 86 FILE *nlfd;
88a01c09 87 char *ttyn;
b4389814 88 int ldisc = 0, zero = 0;
88a01c09 89
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90 signal(SIGALRM, timedout);
91 alarm(timeout);
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92 signal(SIGQUIT, SIG_IGN);
93 signal(SIGINT, SIG_IGN);
3b8dd95e 94 setpriority(PRIO_PROCESS, 0, 0);
22d4760e 95 quota(Q_SETUID, 0, 0, 0);
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SL
96 /*
97 * -r is used by rlogind to cause the autologin protocol;
98 * -h is used by other servers to pass the name of the
99 * remote host to login so that it may be placed in utmp and wtmp
100 */
101 if (argc > 1) {
102 if (strcmp(argv[1], "-r") == 0) {
103 rflag = doremotelogin(argv[2]);
104 SCPYN(utmp.ut_host, argv[2]);
105 argc = 0;
b4389814 106 }
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SL
107 if (strcmp(argv[1], "-h") == 0 && getuid() == 0) {
108 SCPYN(utmp.ut_host, argv[2]);
109 argc = 0;
b4389814 110 }
86eb6c9e 111 }
714accc5 112 ioctl(0, TIOCLSET, &zero);
c95ed2b2 113 ioctl(0, TIOCNXCL, 0);
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114 ioctl(0, FIONBIO, &zero);
115 ioctl(0, FIOASYNC, &zero);
714accc5 116 ioctl(0, TIOCGETP, &ttyb);
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SL
117 /*
118 * If talking to an rlogin process,
119 * propagate the terminal type and
120 * baud rate across the network.
121 */
122 if (rflag)
123 doremoteterm(term, &ttyb);
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SL
124 ioctl(0, TIOCSLTC, &ltc);
125 ioctl(0, TIOCSETC, &tc);
126 ioctl(0, TIOCSETP, &ttyb);
3b8dd95e 127 for (t = getdtablesize(); t > 3; t--)
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128 close(t);
129 ttyn = ttyname(0);
f570e1ff 130 if (ttyn==(char *)0)
88a01c09 131 ttyn = "/dev/tty??";
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132 do {
133 ldisc = 0;
c95ed2b2 134 ioctl(0, TIOCSETD, &ldisc);
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135 invalid = FALSE;
136 SCPYN(utmp.ut_name, "");
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137 /*
138 * Name specified, take it.
139 */
140 if (argc > 1) {
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141 SCPYN(utmp.ut_name, argv[1]);
142 argc = 0;
143 }
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144 /*
145 * If remote login take given name,
146 * otherwise prompt user for something.
147 */
4f8d3876 148 if (rflag) {
3479a16a 149 SCPYN(utmp.ut_name, lusername);
3b8dd95e 150 /* autologin failed, prompt for passwd */
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151 if (rflag == -1)
152 rflag = 0;
4cf9fc9e 153 } else
3b8dd95e 154 getloginname(&utmp);
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155 if (!strcmp(pwd->pw_shell, "/bin/csh")) {
156 ldisc = NTTYDISC;
157 ioctl(0, TIOCSETD, &ldisc);
158 }
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SL
159 /*
160 * If no remote login authentication and
161 * a password exists for this user, prompt
162 * for one and verify it.
163 */
164 if (!rflag && *pwd->pw_passwd != '\0') {
165 char *pp;
166
167 setpriority(PRIO_PROCESS, 0, -4);
168 pp = getpass("Password:");
169 namep = crypt(pp, pwd->pw_passwd);
170 setpriority(PRIO_PROCESS, 0, 0);
171 if (strcmp(namep, pwd->pw_passwd))
172 invalid = TRUE;
f570e1ff 173 }
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SL
174 /*
175 * If user not super-user, check for logins disabled.
176 */
f570e1ff 177 if (pwd->pw_uid != 0 && (nlfd = fopen(nolog, "r")) > 0) {
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178 while ((c = getc(nlfd)) != EOF)
179 putchar(c);
180 fflush(stdout);
181 sleep(5);
182 exit(0);
183 }
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184 /*
185 * If valid so far and root is logging in,
186 * see if root logins on this terminal are permitted.
187 */
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188 if (!invalid && pwd->pw_uid == 0 &&
189 !rootterm(ttyn+sizeof("/dev/")-1)) {
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190 logerr("ROOT LOGIN REFUSED %s",
191 ttyn+sizeof("/dev/")-1);
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192 invalid = TRUE;
193 }
194 if (invalid) {
88a01c09 195 printf("Login incorrect\n");
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196 if (ttyn[sizeof("/dev/tty")-1] == 'd')
197 logerr("BADDIALUP %s %s\n",
198 ttyn+sizeof("/dev/")-1, utmp.ut_name);
88a01c09 199 }
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200 if (*pwd->pw_shell == '\0')
201 pwd->pw_shell = "/bin/sh";
202 i = strlen(pwd->pw_shell);
203 if (chdir(pwd->pw_dir) < 0 && !invalid ) {
204 if (chdir("/") < 0) {
205 printf("No directory!\n");
206 invalid = TRUE;
207 } else {
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SL
208 printf("No directory! %s\n",
209 "Logging in with home=/");
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210 pwd->pw_dir = "/";
211 }
88a01c09 212 }
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213 /*
214 * Remote login invalid must have been because
215 * of a restriction of some sort, no extra chances.
216 */
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217 if (rflag && invalid)
218 exit(1);
f570e1ff 219 } while (invalid);
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SL
220/* committed to login turn off timeout */
221 alarm(0);
88a01c09 222
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SL
223 if (quota(Q_SETUID, pwd->pw_uid, 0, 0) < 0) {
224 if (errno == EUSERS)
225 printf("%s.\n%s.\n",
226 "Too many users logged on already",
227 "Try again later");
228 else if (errno == EPROCLIM)
229 printf("You have too many processes running.\n");
230 else
231 perror("setuid");
232 sleep(5);
233 exit(0);
234 }
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235 time(&utmp.ut_time);
236 t = ttyslot();
3b8dd95e 237 if (t > 0 && (f = open("/etc/utmp", 1)) >= 0) {
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238 lseek(f, (long)(t*sizeof(utmp)), 0);
239 SCPYN(utmp.ut_line, rindex(ttyn, '/')+1);
240 write(f, (char *)&utmp, sizeof(utmp));
241 close(f);
242 }
3b8dd95e 243 if (t > 0 && (f = open("/usr/adm/wtmp", 1)) >= 0) {
88a01c09
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244 lseek(f, 0L, 2);
245 write(f, (char *)&utmp, sizeof(utmp));
246 close(f);
247 }
3b8dd95e 248 quietlog = access(qlog, 0) == 0;
4f8d3876 249 if ((f = open(lastlog, 2)) >= 0) {
f570e1ff
BJ
250 struct lastlog ll;
251
252 lseek(f, (long)pwd->pw_uid * sizeof (struct lastlog), 0);
253 if (read(f, (char *) &ll, sizeof ll) == sizeof ll &&
3b8dd95e
SL
254 ll.ll_time != 0 && !quietlog) {
255 printf("Last login: %.*s ",
256 24-5, (char *)ctime(&ll.ll_time));
257 if (*ll.ll_host != '\0')
258 printf("from %.*s\n",
259 sizeof (ll.ll_host), ll.ll_host);
260 else
261 printf("on %.*s\n",
262 sizeof (ll.ll_line), ll.ll_line);
f570e1ff
BJ
263 }
264 lseek(f, (long)pwd->pw_uid * sizeof (struct lastlog), 0);
265 time(&ll.ll_time);
266 SCPYN(ll.ll_line, rindex(ttyn, '/')+1);
3b8dd95e 267 SCPYN(ll.ll_host, utmp.ut_host);
f570e1ff
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268 write(f, (char *) &ll, sizeof ll);
269 close(f);
270 }
88a01c09 271 chown(ttyn, pwd->pw_uid, pwd->pw_gid);
3479a16a 272 chmod(ttyn, 0622);
88a01c09 273 setgid(pwd->pw_gid);
e5321f7b
KM
274 strncpy(name, utmp.ut_name, NMAX);
275 name[NMAX] = '\0';
b1198826 276 initgroups(name, pwd->pw_gid);
22d4760e 277 quota(Q_DOWARN, pwd->pw_uid, (dev_t)-1, 0);
88a01c09 278 setuid(pwd->pw_uid);
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279 environ = envinit;
280 strncat(homedir, pwd->pw_dir, sizeof(homedir)-6);
281 strncat(shell, pwd->pw_shell, sizeof(shell)-7);
4f8d3876 282 if (term[strlen("TERM=")] == 0)
86eb6c9e 283 strncat(term, stypeof(ttyn), sizeof(term)-6);
f570e1ff 284 strncat(user, pwd->pw_name, sizeof(user)-6);
88a01c09
BJ
285 if ((namep = rindex(pwd->pw_shell, '/')) == NULL)
286 namep = pwd->pw_shell;
287 else
288 namep++;
289 strcat(minusnam, namep);
b4389814 290 umask(022);
4f8d3876
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291 if (ttyn[sizeof("/dev/tty")-1] == 'd')
292 logerr("DIALUP %s %s\n", ttyn+sizeof("/dev/")-1, pwd->pw_name);
293 if (!quietlog) {
f570e1ff
BJ
294 showmotd();
295 strcat(maildir, pwd->pw_name);
296 if (access(maildir,4)==0) {
297 struct stat statb;
298 stat(maildir, &statb);
299 if (statb.st_size)
300 printf("You have mail.\n");
301 }
302 }
3b8dd95e 303 signal(SIGALRM, SIG_DFL);
88a01c09
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304 signal(SIGQUIT, SIG_DFL);
305 signal(SIGINT, SIG_DFL);
5f87416f 306 signal(SIGTSTP, SIG_IGN);
88a01c09 307 execlp(pwd->pw_shell, minusnam, 0);
f570e1ff 308 perror(pwd->pw_shell);
88a01c09
BJ
309 printf("No shell\n");
310 exit(0);
311}
312
3b8dd95e
SL
313getloginname(up)
314 register struct utmp *up;
315{
316 register char *namep;
5a786176 317 char c;
3b8dd95e 318
3b8dd95e
SL
319 while (up->ut_name[0] == '\0') {
320 namep = utmp.ut_name;
5a786176 321 printf("login: ");
3b8dd95e
SL
322 while ((c = getchar()) != '\n') {
323 if (c == ' ')
324 c = '_';
325 if (c == EOF)
326 exit(0);
327 if (namep < up->ut_name+NMAX)
328 *namep++ = c;
329 }
330 }
331 setpwent();
332 if ((pwd = getpwnam(utmp.ut_name)) == NULL)
333 pwd = &nouser;
334 endpwent();
335}
336
337timedout()
338{
339
340 printf("Login timed out after %d seconds\n", timeout);
341 exit(0);
342}
343
88a01c09
BJ
344int stopmotd;
345catch()
346{
1886582e 347
88a01c09
BJ
348 signal(SIGINT, SIG_IGN);
349 stopmotd++;
350}
351
f570e1ff 352rootterm(tty)
1886582e 353 char *tty;
f570e1ff
BJ
354{
355 register FILE *fd;
1886582e 356 char buf[100];
f570e1ff
BJ
357
358 if ((fd = fopen(securetty, "r")) == NULL)
359 return(1);
360 while (fgets(buf, sizeof buf, fd) != NULL) {
361 buf[strlen(buf)-1] = '\0';
362 if (strcmp(tty, buf) == 0) {
363 fclose(fd);
364 return(1);
365 }
366 }
367 fclose(fd);
368 return(0);
369}
370
88a01c09
BJ
371showmotd()
372{
373 FILE *mf;
374 register c;
375
376 signal(SIGINT, catch);
f570e1ff
BJ
377 if ((mf = fopen("/etc/motd","r")) != NULL) {
378 while ((c = getc(mf)) != EOF && stopmotd == 0)
88a01c09
BJ
379 putchar(c);
380 fclose(mf);
381 }
382 signal(SIGINT, SIG_IGN);
383}
384
f570e1ff 385#undef UNKNOWN
88a01c09
BJ
386#define UNKNOWN "su"
387
388char *
389stypeof(ttyid)
3b8dd95e 390 char *ttyid;
88a01c09 391{
3b8dd95e
SL
392 static char typebuf[16];
393 char buf[50];
394 register FILE *f;
395 register char *p, *t, *q;
88a01c09
BJ
396
397 if (ttyid == NULL)
398 return (UNKNOWN);
399 f = fopen("/etc/ttytype", "r");
400 if (f == NULL)
401 return (UNKNOWN);
402 /* split off end of name */
403 for (p = q = ttyid; *p != 0; p++)
404 if (*p == '/')
405 q = p + 1;
406
407 /* scan the file */
3b8dd95e
SL
408 while (fgets(buf, sizeof buf, f) != NULL) {
409 for (t = buf; *t != ' ' && *t != '\t'; t++)
88a01c09
BJ
410 ;
411 *t++ = 0;
f570e1ff
BJ
412 while (*t == ' ' || *t == '\t')
413 t++;
3b8dd95e 414 for (p = t; *p > ' '; p++)
88a01c09
BJ
415 ;
416 *p = 0;
3b8dd95e 417 if (strcmp(q,t) == 0) {
88a01c09
BJ
418 strcpy(typebuf, buf);
419 fclose(f);
420 return (typebuf);
421 }
422 }
423 fclose (f);
424 return (UNKNOWN);
425}
86eb6c9e 426
3b8dd95e
SL
427doremotelogin(host)
428 char *host;
429{
430 FILE *hostf;
431 int first = 1;
432
433 getstr(rusername, sizeof (rusername), "remuser");
434 getstr(lusername, sizeof (lusername), "locuser");
435 getstr(term+5, sizeof(term)-5, "Terminal type");
4cf9fc9e
SL
436 if (getuid()) {
437 pwd = &nouser;
3b8dd95e 438 goto bad;
4cf9fc9e 439 }
3b8dd95e
SL
440 setpwent();
441 pwd = getpwnam(lusername);
442 endpwent();
4cf9fc9e
SL
443 if (pwd == NULL) {
444 pwd = &nouser;
3b8dd95e 445 goto bad;
4cf9fc9e 446 }
3b8dd95e
SL
447 hostf = pwd->pw_uid ? fopen("/etc/hosts.equiv", "r") : 0;
448again:
449 if (hostf) {
450 char ahost[32];
451
452 while (fgets(ahost, sizeof (ahost), hostf)) {
453 char *user;
454
455 if ((user = index(ahost, '\n')) != 0)
456 *user++ = '\0';
457 if ((user = index(ahost, ' ')) != 0)
458 *user++ = '\0';
459 if (!strcmp(host, ahost) &&
460 !strcmp(rusername, user ? user : lusername)) {
461 fclose(hostf);
462 return (1);
463 }
464 }
465 fclose(hostf);
466 }
467 if (first == 1) {
468 char *rhosts = ".rhosts";
469 struct stat sbuf;
470
471 first = 0;
472 if (chdir(pwd->pw_dir) < 0)
473 goto again;
474 if (lstat(rhosts, &sbuf) < 0)
475 goto again;
476 if ((sbuf.st_mode & S_IFMT) == S_IFLNK) {
477 printf("login: .rhosts is a soft link.\r\n");
478 goto bad;
479 }
480 hostf = fopen(rhosts, "r");
481 fstat(fileno(hostf), &sbuf);
482 if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid) {
483 printf("login: Bad .rhosts ownership.\r\n");
484 fclose(hostf);
485 goto bad;
486 }
487 goto again;
488 }
489bad:
490 return (-1);
491}
492
86eb6c9e
BJ
493getstr(buf, cnt, err)
494 char *buf;
495 int cnt;
496 char *err;
497{
498 char c;
499
500 do {
501 if (read(0, &c, 1) != 1)
502 exit(1);
503 if (--cnt < 0) {
504 printf("%s too long\r\n", err);
505 exit(1);
506 }
507 *buf++ = c;
508 } while (c != 0);
509}
4f8d3876 510
3b8dd95e
SL
511char *speeds[] =
512 { "0", "50", "75", "110", "134", "150", "200", "300",
513 "600", "1200", "1800", "2400", "4800", "9600", "19200", "38400" };
514#define NSPEEDS (sizeof (speeds) / sizeof (speeds[0]))
515
516doremoteterm(term, tp)
517 char *term;
518 struct sgttyb *tp;
519{
520 char *cp = index(term, '/');
521 register int i;
522
523 if (cp) {
524 *cp++ = 0;
525 for (i = 0; i < NSPEEDS; i++)
526 if (!strcmp(speeds[i], cp)) {
527 tp->sg_ispeed = tp->sg_ospeed = i;
528 break;
529 }
530 }
531 tp->sg_flags = ECHO|CRMOD|ANYP|XTABS;
532}
533
4f8d3876
BJ
534logerr(fmt, a1, a2, a3)
535 char *fmt, *a1, *a2, *a3;
536{
da9c63f2
SL
537#ifdef LOGERR
538 FILE *cons = fopen("/dev/console", "w");
4f8d3876 539
da9c63f2
SL
540 if (cons != NULL) {
541 fprintf(cons, fmt, a1, a2, a3);
542 fputc('\r', cons);
543 fclose(cons);
544 }
545#endif
4f8d3876 546}