dave@andromeda.UUCP (Dave Bloom) (09/26/85)
Here's the story:
I'm writing my own version of "idledaemon" but I'd like a few suggestions from
the net. Namely, what's the best way to get the pid of a users login shell? The
SystemV command 'who -u' supplies the number, but I can't find anything in the
4.2 BSD universe that does the same. Any suggestions? Any idea how AT&T does
it in 'who', and can it be done similarly in 4.2 BSD?
Thanx.
--
-------------------------------------------------------------------------------
allegra\ Dave Bloom
harvard \ pyramid\
seismo \ pyrnj >!andromeda!dave HOME: (201) 868-1764
ut-sally >!topaz/ WORK: (201) 648-5083
sri-iu /
ihnp4!packard / "You're never alone with a schizophrenic...."pds@mit-vax.UUCP (Philip Steen) (09/29/85)
In article <4@andromeda.UUCP> version B 2.10.2 9/18/84; site mit-vax.UUCP version B 2.10.3 4.3bsd-beta 6/6/85; site andromeda.UUCP mit-vax!mit-eddie!think!harvard!seismo!columbia!topaz!andromeda!dave dave@andromeda.UUCP (Dave Bloom) writes: >... what's the best way to get the pid of a users login shell? >... can it be done similarly in 4.2 BSD? Sure it can. The shell variable $$ gets the pid for you, use it thusly in the C-Shell: set pid=$$ echo "the pid of this shell is $$" One can do something similar in the Bourne Shell.
itkin@luke.UUCP (Steven List) (10/01/85)
In article <4@andromeda.UUCP> dave@andromeda.UUCP (Dave Bloom) writes: >I'm writing my own version of "idledaemon" but I'd like a few suggestions from >the net. Namely, what's the best way to get the pid of a users login shell? The >SystemV command 'who -u' supplies the number, but I can't find anything in the >4.2 BSD universe that does the same. Any suggestions? Any idea how AT&T does >it in 'who', and can it be done similarly in 4.2 BSD? System V (and III) use /etc/utmp to store information about logged in users. There is an include file <utmp.h> described in section 4 of the Programmer Reference Manual that describes the structure of each /etc/utmp entry. As I recall, in S5 there is also a set of functions that will read and write /etc/utmp for you. -- *** * Steven List @ Benetics Corporation, Mt. View, CA * Just part of the stock at "Uncle Bene's Farm" * {cdp,greipa,idi,oliveb,sun,tolerant}!bene!luke!itkin ***
mikel@codas.UUCP (Mikel Manitius) (10/06/85)
> Here's the story: > > I'm writing my own version of "idledaemon" but I'd like a few suggestions from > the net. Namely, what's the best way to get the pid of a users login shell? The > SystemV command 'who -u' supplies the number, but I can't find anything in the > 4.2 BSD universe that does the same. Any suggestions? Any idea how AT&T does > it in 'who', and can it be done similarly in 4.2 BSD? > > Thanx. > -- > ------------------------------------------------------------------------------- > allegra\ Dave Bloom > harvard \ pyramid\ > seismo \ pyrnj >!andromeda!dave HOME: (201) 868-1764 > ut-sally >!topaz/ WORK: (201) 648-5083 > sri-iu / > ihnp4!packard / "You're never alone with a schizophrenic...." Under System V, the login shell's pid is stored in /etc/utmp, the follwing is the contents of /usr/include/utmp.h ------- /* @(#)utmp.h 1.2 */ /* @(#)utmp.h 3.2 */ /* <sys/types.h> must be included. */ #define UTMP_FILE "/etc/utmp" #define WTMP_FILE "/etc/wtmp" #define ut_name ut_user struct utmp { char ut_user[8] ; /* User login name */ char ut_id[4] ; /* /etc/lines id(usually line #) */ char ut_line[12] ; /* device name (console, lnxx) */ short ut_pid ; /* process id */ short ut_type ; /* type of entry */ struct exit_status { short e_termination ; /* Process termination status */ short e_exit ; /* Process exit status */ } ut_exit ; /* The exit status of a process * marked as DEAD_PROCESS. */ time_t ut_time ; /* time entry was made */ } ; /* Definitions for ut_type */ #define EMPTY 0 #define RUN_LVL 1 #define BOOT_TIME 2 #define OLD_TIME 3 #define NEW_TIME 4 #define INIT_PROCESS 5 /* Process spawned by "init" */ #define LOGIN_PROCESS 6 /* A "getty" process waiting for login */ #define USER_PROCESS 7 /* A user process */ #define DEAD_PROCESS 8 #define ACCOUNTING 9 #define UTMAXTYPE ACCOUNTING /* Largest legal value of ut_type */ /* Special strings or formats used in the "ut_line" field when */ /* accounting for something other than a process. */ /* No string for the ut_line field can be more than 11 chars + */ /* a NULL in length. */ #define RUNLVL_MSG "run-level %c" #define BOOT_MSG "system boot" #define OTIME_MSG "old time" #define NTIME_MSG "new time" ------------- And you just read all the entries that have a ut_type equal to USER_PROCESS. This does not exist on BSD systems, however, I once wrote a kill idle program on a V8 System, you don't really need to know the person's root pid, just read /etc/utmp and get his ut_line, check the access times to determine if he is idle, and if so, set sg.sg_ispeed and sg.sg_ospeed to 0 (from sgtty.h, or, I beleive stty.h on BSD), then stty(3) or ioctl(2) his terminal with this (as long as you have modem control) and he will be logged off. Also, it's nice to warn the person that he will be nuked if he remains idle for another few minutes, then nuke him. -- ======= Mikel Manitius ==----===== AT&T (305) 869-2462 RNX: 755 ==------===== Information Systems ...{akguc|ihnp4}!codas!mikel ===----====== SDSS Regional Support ...attmail!mmanitius =========== Altamonte Springs, FL My opinions are my own. =======