Michael J. Hammel
mjhammel at graphics-muse.org
Thu Sep 7 16:54:18 MDT 2000
Thus spoke John Starkey
> I need to have reminders show up on the screen and some I want emailed. If
> I write a script to simply echo "whatever I need to say to myself" how
> would I require a certain keystroke to confirm? ( an IF statement maybe??
As far as I know you can't do this. Cron runs without being attached to a
vt and it can't be told to grab a vt directly - the program you run will
have to do that. For example, under X (which I know you don't want) I can
run xmessage or gmessage or whatever from cron *if* "xhost +localhost" was
run on that display already. gmessage (or whatever) will prompt for user
input - and can do so because it has a connection to a display. There
isn't a shell connected to a vt under cron, so your program called from
cron would have to open a vt and try to read/write from it. In other
words, setting the following line as a cron job:
echo "this is a test message"
causes the output to go into /dev/null from cron. There isn't any place for
cron to display it.
Cron is specifically designed to run in the background without user
interaction, so I think adding user interaction from it is kind of a
security violation. Or at least I think it's generally frowned upon.
> Is it possible to do this on ttyS[1-6] and have input from one confirm for
> all the vt's??
Leave cron out of the picture and ask yourself if you can write a program
to do this just from your own shell prompt. The answer is "probably not" -
at least not easily. You might be able to do it in Perl. I'd do it in C.
Cron just launches programs and doesn't give them access to a terminal
(display) device. It really doesn't care too much what the program does.
> And in the daily entry in crontab what do the "*" represent. If I remember
> correctly they're 15 minute increments in the hourly line.
No, they're a wildcard meaning "any". So if a * was in the hour field, it
would mean do it every hour. If the * was in the day field, it would mean
do it every day.
Michael J. Hammel |
The Graphics Muse | And your crybaby whiny-assed opinion would
mjhammel at graphics-muse.org | be...?
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