i wanna make an alias for shutdown and reboot, and i need them to be available to all users from any terminal
alias off="/sbin/shutdown -h now"
alias reb="/sbin/shutdown -r now"
what is the file i should add these lines to ?
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i've set the permissions for shutdown

If you want aliases to be globally available and your default shell is Bash then create a file in /etc/profile.d with custom aliases readable for all. However 0) having unprivileged users execute commands to be issued by root or the admin group alone itself, 1) especially on multi-user machines and 2) with alias names that don't really make sense nor 3) allow any connected user to save files etc, etc, may cause interesting and unexpected situations. If it makes sense to you then you will also set the binary setuid-root, which isn't a security best practice anyway, or use an /etc/sudoers NOPASSWD entry so any user can actually execute the command. If in the future any damage occurs because of your craving for interesting and unexpected situations then you're completely SOL as far as I'm concerned: there's best practices, standard procedures and things you just shouldn't do.

Instead of aliases, create scripts with the corresponding names and put them in /usr/bin for example. Thus you could use them no matter the shell.

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i checked "profile.d" directory, it's full of shell scripts. every user read all the scripts their when he login :O ???
i just want it alias
i'm the only user of my laptop, and i dont care about security issues right now i dont have " Clasified " on my top ,um justn learning. i have 2 users on my slackware, when i want to reboot or shutdown i must switch to root first, i just want to be able to reboot my machine without switching to root, by any user and from any terminal. i know there are files in every user's home directory are read after login to set his environment variables, is there a file which is read by all users to set a global alias their ???
and if so what should i write then to make the alias work from any terminal.

When using the Bash shell /etc/profile is not the correct place for aliases. The profile file(s) is/are only run by bash 'login shells' so any non-login child shells, such as those that get started within an xterm, aren't going to have the aliases defined. Aliases are local to the shell instance and can't be exported in the same manner as environment variables and will not be inherited by child shells.

The only file that gets run by interactive non-login bash shells is the users ~/.bashrc, but there is no global /etc/bashrc that gets run automatically. But it gets worse, because if you put the aliases in the bashrc, they're not available in 'login' bash shells as they only run the profile file(s) and not the bashrc.

By making the distinction between the two types of shell and not having a common file that gets run by both types of shell, the bash developers have made life a little difficult here.

You need to call one from the other to be sure. I've seen some people advocate calling /etc/profile from your ~/.bashrc but the bash documentation makes it clear that /etc/profile is intended to be run once only for login shells and if you want to respect that concept you want to do it the other way around with something like the following somewhere in your /etc/profile or /etc/profile.d
You can then put your aliases, Prompt string ($PS1) and so on in your ~/.bashrc and they will be available from both types of bash shell (login and non-login).

If you want to have a global bashrc shared between all users then you can create an /etc/bashrc to contain it, but you'll still need to add something like the following to each users ~/bashrc to call it
Unfortunately, this still relies on each user having a ~/.bashrc, but until bash provides support for a global /etc/bashrc in the same manner as /etc/profile, I see no way around this.


Anyway, that aside, I agree with Perceptor: wrapper scripts in /usr/local/bin will probably serve you better in this specific case. Especially so if you take care to use them safely through sudo.

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I'm pretty much aware of the differences in startup script usage when the shell is called as compatible 'sh' or as 'bash' and when it's called as interactive login or as interactive non-login shell or non-interactive shell. On most systems, that is. Clearly this didn't apply to slackware as it by default doesn't even carry shell initialization files in /etc/skel/, so there's no enforced uniformity to speak of anyway, except the guidelines the slackware bash manual page puts forth which I obviously should have read more closely. Anyway, "safe" usage of sudo sounds nice but it in no way addresses stuff like data loss when a user forces a 'shutdown -r now' on others...

Yes, I think this is one of those issues where Slackware's critics would point to it and say "it lacks polish", while its defenders would argue that "Slackware doesn't make any assumptions and it's left to the local admin to set it up how they want it.".

Personally, I don't care for the way the Slackware shell invocation/profile setup has been done, but then I'm not that keen on the RHEL one either, and fixing a few little niggles like this is a lot easier than having to yank out whole subsystems such as pulseaudio to get to something I can live with..

thanQ guys .. it's really too much valuable information n i think i'll forget abot the alias and i'll just write " /sbin/shutdown -r|h now " easier lol

Wise choice.

Personally, I just press the power button to shutdown,
and ctrl-alt-f1 + ctrl-alt-delete to reboot.

I had to solve the same problem when I built my home theater PC. I wanted to allow anybody using the remote control to shut down the box.

In /usr/local/sbin I created three special shell scripts named safe-reboot, safe-halt, and safe-shutdown. The first two point to the safe-shutdown script and only distinguish between root and non-root accounts to use sudo when appropriate. The safe-shutdown script performs numerous checks such as whether a recording is in session and refuses to reboot/shutdown in such cases.

I modified /etc/inittab to use safe-reboot when using the three finger salute (Ctrl-Alt-Del).

I modified the KDM login manager to use those scripts rather than the standard /sbin/reboot and shutdown commands.

I placed two aliases for shutdown and reboot in /etc/bashrc that pointed to my safe-shutdown and safe-reboot scripts. I source that file in ~/.bashrc.

I added the HTPC user account name to the /etc/sudoers list and allow that account to run /sbin/halt, /sbin/shutdown, /usr/local/sbin/safe-halt, /usr/local/sbin/safe-reboot, and /usr/local/sbin/safe-shutdown.

Of course, I always can login as root (locally or ssh) and directly run /sbin/shutdown and /sbin/reboot to force either event.

A caveat with allowing any user to reboot or shutdown is determining whether other users are logged in. 'nix systems are multi-user. Those are some of the kind of tests my safe-shutdown script performs.

You can read more:

Harmonizing the Bash Startup Scripts
Improving Scripts and Safe Shutdown

@GAZL --> that what i always looking for just pressing one button for every action
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@woodsman --> ya it's really nice idea for organizing the work , but still alot of work and i chose Slackware to avoid doing many things ;
) anyway ,i'm sure that i'll follow this harmony between scripts but not now i guess thx