difference between poweroff and shutdown -h now

[vickey_20]

Hey ppl
I just found out that system can be shutdowned by shutdown -h now command and was wondering the difference between the it and poweroff and also can any one tell me how to pass a message in the shutdown command.
thanks for your replies.

[vickey_20]

this is confusing me , y can't a normal user use the shutdown command ???

[vickey_20]

also how can i get to view the source code of shutdown as vi command can't open shutdown script( it opens but it's in unreadable format)

[oz]

this is confusing me , y can't a normal user use the shutdown command ???

Allowing a normal user to shutdown a Unix machine would be considered a security issue. Normal users can shutdown if you set them up to do so with the sudo command.

[Jonathan183]

Switch off power to shutdown is not a good idea ... it is better to go through a controlled shutdown which will write disk cache and unmount file systems.

A normal user is unable to shutdown a system without being given rights to do so (use sudo to do this) ... allowing a normal user logged on remotely to shutdown a server makes little sense.

If you are running a graphical login manager like kdm then there is normally an option to allow shutdown of system (assuming you have a desktop or laptop system) ... what distro are you using?

[vickey_20]

I am using red hat 5
I guess i understood the use( plz correct me If I am wrong)
shutdown - is for shutting down the server
poweroff- is for shutting down the client

[saivin]

A normal user is unable to shutdown a system without being given rights to do so (use sudo to do this) ... allowing a normal user logged on remotely to shutdown a server makes little sense.

If you are running a graphical login manager like kdm then there is normally an option to allow shutdown of system (assuming you have a desktop or laptop system) ... what distro are you using?

Whats difference does it make to security if I can shutdown/reboot from graphical menu but cannot use the shutdown command from terminal on the same system?

Also, is there a difference between shutdown and halt? Coz, in FreeBSD when I tried

shutdown -h now

It says system halted. Enter reboot to restart the system. It stays in the root prompt.

[saivin]

shutdown - is for shutting down the server
poweroff- is for shutting down the client

No, there is no such distinction.

[Jonathan183]

Sorry I had misunderstood the question ...
but man shutdown and man poweroff show differences
from man pages

shutdown brings the system down in a secure way.

and from halt man page

-f Force halt or reboot, don't call shutdown(.

I always use shutdown ...

Allowing any user to execute shutdown, poweroff or halt would cause problems ... I think kdm limits shutdown option to local users only, and regular users are unable to start kdm.

[vickey_20]

No, there is no such distinction.

Then are they both same!!!