UNIX for Dummies Questions & Answers

Hi there,
I start using the function shutdown instead of reboot + poweroff.
But there are some points that are not explained in the man pages.

1) What is the usage of the t swith.
Both commands will display the message immediatly on every terminal and shutdown at 22:30. Where is the difference?

2) Can I specify the date/time like in the date command?
Thanks for your help
Santiago

Post the output of "uname -a" so we know what OS you're using.

Hi Perderabo, here is the result:
It's a Debian

You should have a man page that states

"-t sec
Tell init(8) to wait sec seconds between sending processes the warning and the kill signal, before changing to another runlevel."

When the shutdown occurs, a program called init must kill running processes. To do this it first does the equivalent of a "kill -15 pid" and if that doesn't work, it will do the equivalent of a "kill -9 pid". The -t is affecting how long init waits between the two kills. The default is 5 seconds. So a "-t 120" might take longer to complete the shutdown. But if the first kill works, init will never try the second kill. In that case, the -t could have no effect at all.

Thanks Perderabo, I quite understand.
With my little knowledge, I thought that the warning sent before the kill signal was the message displayed by shutdown. That's why I was confused to see that this warning message was displayed exactly the same in both cases.
About my other question, do you have any clue?
I'd like to be have a command to reboot my server giving the other users 5 minuts to close their work in progress. How can I achieve something like:

Code:

shutdown -r 'now + 5 minute' 'beware, rebooting in 5 minutes!'

You really need to read that man page.

"The time argument can have different formats. First, it can be an absolute time in the format hh:mm, in which hh is the hour (1 or 2 digits) and mm is the minute of the hour (in two digits). Second, it can be in the format +m, in which m is the number of minutes to wait. The word now is an alias for +0."


If you want to wait 5 minutes it's just +5.

You're right Perderabo, I have been really distracted on that point.
Everything's clear now.
Thanks for your help.