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Apur-phy.260 net.bugs.2bsd utcsrgv!utzoo!decvax!pur-ee!purdue!pur-phy!crl Mon Mar 29 13:27:45 1982 A fix to the w.c bug fix (sigh) Well, I guess I spoke too soon with my previous bug fix. There's a problem that I didn't notice before. This occurs when someone is logged on has an 8-character user name. Because most of the users around here have short id's, I missed this point in testing. The entry in utmp is not guaranteed to be null-terminated, so the call to getpwnam() returns NULL when that happens. The fix is indicated below. Also, if you haven't done so already, it is really advantageous to make w be setuid to root so that it can use the phys() system call (if you have it). This reduces system time used by about 5 sec.

Charles LaBrec pur-ee!physics:crl

---------------------------------------- *** w.c.old Mon Mar 29 13:11:10 1982 --- w.c Mon Mar 29 13:14:11 1982 *************** *** 108,114 { int days, hrs, mins; register int i, j; ! char *cp; register int curpid, empty; struct passwd *pwptr;

--- 108,114 ----- { int days, hrs, mins; register int i, j; ! char *cp, tmp[9]; register int curpid, empty; struct passwd *pwptr;

*************** *** 235,241 } if (utmp.ut_name[0] == '\0') continue; /* that tty is free */ ! if ((pwptr = getpwnam(utmp.ut_name)) == NULL ) continue; /* can't figure out who's on it */ uid = pwptr->pw_uid; if (sel_user && strncmp(utmp.ut_name, sel_user, 8) != 0)

--- 235,243 ----- } if (utmp.ut_name[0] == '\0') continue; /* that tty is free */ ! strncpy(tmp, utmp.ut_name, 8); ! tmp[8] = '\0'; /* make sure it's null-terminated */ ! if ((pwptr = getpwnam(tmp)) == NULL ) continue; /* can't figure out who's on it */ uid = pwptr->pw_uid; if (sel_user && strncmp(utmp.ut_name, sel_user, 8) != 0)

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