[4953] in Athena Bugs
getty tty name printing (from comp.bugs.4bsd)
daemon@ATHENA.MIT.EDU (Jonathan I. Kamens)
Sun May 20 13:05:51 1990
Date: Sun, 20 May 90 13:05:37 -0400
From: Jonathan I. Kamens <jik@pit-manager.MIT.EDU>
To: bugs@ATHENA.MIT.EDU
In article <5817@videovax.tv.tek.com>, bart@videovax.tv.tek.com (Bart
Massey) writes:
|> Program: /usr/src/etc/getty
|> Version: 4.3BSD "Tahoe"
|> Machine: VAX 11/750
|>
|> It seems to me that the call to ttyname() near line 445 in putf() in
|> getty/main.c is both expensive and incorrect. I think the proper way to
|> expand "%t" is using the tty name already determined and stored in
the global
|> "ttyn". The reason I noticed it is that some of our ttys are symlinked, and
|> getty was printing the name of the tty, rather than the name of the link,
|> the latter having been passed as an argument to getty. Also note that
|> ttyname() requires a scan of /dev/, and is thus pretty costly, even
|> considering the caches.
|>
|> Is there some security reason that I shouldn't do the following?
|>
|> Bart Massey
|> ..tektronix!videovax.tv.tek.com!bart
|> ..tektronix!reed.bitnet!bart
|>
|> *** /tmp/,RCSt1022702 Fri May 18 17:24:19 1990
|> --- main.c Fri May 18 17:24:02 1990
|> ***************
|> *** 429,438 ****
|> putf(cp)
|> register char *cp;
|> {
|> ! char *ttyn, *slash;
|> char datebuffer[60];
|> extern char editedhost[];
|> ! extern char *ttyname(), *rindex();
|>
|> while (*cp) {
|> if (*cp != '%') {
|> --- 429,438 ----
|> putf(cp)
|> register char *cp;
|> {
|> ! char *slash;
|> char datebuffer[60];
|> extern char editedhost[];
|> ! extern char *rindex();
|>
|> while (*cp) {
|> if (*cp != '%') {
|> ***************
|> *** 442,448 ****
|> switch (*++cp) {
|>
|> case 't':
|> - ttyn = ttyname(0);
|> slash = rindex(ttyn, '/');
|> if (slash == (char *) 0)
|> puts(ttyn);
|> --- 442,447 ----
Jonathan Kamens USnail:
MIT Project Athena 11 Ashford Terrace
jik@Athena.MIT.EDU Allston, MA 02134
Office: 617-253-8495 Home: 617-782-0710
